There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.
# Code examples for Elastic Load Balancing - Version 2 using AWS SDKs
The following code examples show you how to use Elastic Load Balancing - Version 2 with an AWS software development kit (SDK).
*Actions* are code excerpts from larger programs and must be run in context. While actions show you how to call individual service functions, you can see actions in context in their related scenarios.
*Scenarios* are code examples that show you how to accomplish specific tasks by calling multiple functions within a service or combined with other AWS services.
**More resources**
+ **[ Elastic Load Balancing - Version 2 User Guide](https://docs.aws.amazon.com/elasticloadbalancing/latest/userguide/what-is-load-balancing.html)** – More information about Elastic Load Balancing - Version 2.
+ **[Elastic Load Balancing - Version 2 API Reference](https://docs.aws.amazon.com/elasticloadbalancing/latest/APIReference/Welcome.html)** – Details about all available Elastic Load Balancing - Version 2 actions.
+ **[AWS Developer Center](https://aws.amazon.com/developer/code-examples/?awsf.sdk-code-examples-product=product%23elb)** – Code examples that you can filter by category or full-text search.
+ **[AWS SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples)** – GitHub repo with complete code in preferred languages. Includes instructions for setting up and running the code.
**Contents**
+ [Basics](elastic-load-balancing-v2_code_examples_basics.md)
+ [Hello Elastic Load Balancing](elastic-load-balancing-v2_example_elastic-load-balancing-v2_Hello_section.md)
+ [Actions](elastic-load-balancing-v2_code_examples_actions.md)
+ [`AddListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_AddListenerCertificates_section.md)
+ [`AddTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_AddTags_section.md)
+ [`CreateListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateListener_section.md)
+ [`CreateLoadBalancer`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateLoadBalancer_section.md)
+ [`CreateRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateRule_section.md)
+ [`CreateTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateTargetGroup_section.md)
+ [`DeleteListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteListener_section.md)
+ [`DeleteLoadBalancer`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteLoadBalancer_section.md)
+ [`DeleteRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteRule_section.md)
+ [`DeleteTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteTargetGroup_section.md)
+ [`DeregisterTargets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeregisterTargets_section.md)
+ [`DescribeAccountLimits`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeAccountLimits_section.md)
+ [`DescribeListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeListenerCertificates_section.md)
+ [`DescribeListeners`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeListeners_section.md)
+ [`DescribeLoadBalancerAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeLoadBalancerAttributes_section.md)
+ [`DescribeLoadBalancers`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeLoadBalancers_section.md)
+ [`DescribeRules`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeRules_section.md)
+ [`DescribeSslPolicies`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeSslPolicies_section.md)
+ [`DescribeTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTags_section.md)
+ [`DescribeTargetGroupAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetGroupAttributes_section.md)
+ [`DescribeTargetGroups`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetGroups_section.md)
+ [`DescribeTargetHealth`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetHealth_section.md)
+ [`ModifyListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyListener_section.md)
+ [`ModifyLoadBalancerAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyLoadBalancerAttributes_section.md)
+ [`ModifyRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyRule_section.md)
+ [`ModifyTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyTargetGroup_section.md)
+ [`ModifyTargetGroupAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyTargetGroupAttributes_section.md)
+ [`RegisterTargets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RegisterTargets_section.md)
+ [`RemoveListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RemoveListenerCertificates_section.md)
+ [`RemoveTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RemoveTags_section.md)
+ [`SetIpAddressType`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetIpAddressType_section.md)
+ [`SetRulePriorities`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetRulePriorities_section.md)
+ [`SetSecurityGroups`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetSecurityGroups_section.md)
+ [`SetSubnets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetSubnets_section.md)
+ [Scenarios](elastic-load-balancing-v2_code_examples_scenarios.md)
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
# Basic examples for Elastic Load Balancing - Version 2 using AWS SDKs
The following code examples show how to use the basics of Elastic Load Balancing - Version 2 with AWS SDKs.
**Contents**
+ [Hello Elastic Load Balancing](elastic-load-balancing-v2_example_elastic-load-balancing-v2_Hello_section.md)
+ [Actions](elastic-load-balancing-v2_code_examples_actions.md)
+ [`AddListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_AddListenerCertificates_section.md)
+ [`AddTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_AddTags_section.md)
+ [`CreateListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateListener_section.md)
+ [`CreateLoadBalancer`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateLoadBalancer_section.md)
+ [`CreateRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateRule_section.md)
+ [`CreateTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateTargetGroup_section.md)
+ [`DeleteListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteListener_section.md)
+ [`DeleteLoadBalancer`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteLoadBalancer_section.md)
+ [`DeleteRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteRule_section.md)
+ [`DeleteTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteTargetGroup_section.md)
+ [`DeregisterTargets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeregisterTargets_section.md)
+ [`DescribeAccountLimits`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeAccountLimits_section.md)
+ [`DescribeListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeListenerCertificates_section.md)
+ [`DescribeListeners`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeListeners_section.md)
+ [`DescribeLoadBalancerAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeLoadBalancerAttributes_section.md)
+ [`DescribeLoadBalancers`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeLoadBalancers_section.md)
+ [`DescribeRules`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeRules_section.md)
+ [`DescribeSslPolicies`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeSslPolicies_section.md)
+ [`DescribeTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTags_section.md)
+ [`DescribeTargetGroupAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetGroupAttributes_section.md)
+ [`DescribeTargetGroups`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetGroups_section.md)
+ [`DescribeTargetHealth`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetHealth_section.md)
+ [`ModifyListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyListener_section.md)
+ [`ModifyLoadBalancerAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyLoadBalancerAttributes_section.md)
+ [`ModifyRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyRule_section.md)
+ [`ModifyTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyTargetGroup_section.md)
+ [`ModifyTargetGroupAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyTargetGroupAttributes_section.md)
+ [`RegisterTargets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RegisterTargets_section.md)
+ [`RemoveListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RemoveListenerCertificates_section.md)
+ [`RemoveTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RemoveTags_section.md)
+ [`SetIpAddressType`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetIpAddressType_section.md)
+ [`SetRulePriorities`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetRulePriorities_section.md)
+ [`SetSecurityGroups`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetSecurityGroups_section.md)
+ [`SetSubnets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetSubnets_section.md)
# Hello Elastic Load Balancing
The following code examples show how to get started using Elastic Load Balancing.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
```
public class HelloLoadBalancer {
public static void main(String[] args) {
ElasticLoadBalancingV2Client loadBalancingV2Client = ElasticLoadBalancingV2Client.builder()
.region(Region.US_EAST_1)
.build();
DescribeLoadBalancersResponse loadBalancersResponse = loadBalancingV2Client
.describeLoadBalancers(r -> r.pageSize(10));
List loadBalancerList = loadBalancersResponse.loadBalancers();
for (LoadBalancer lb : loadBalancerList)
System.out.println("Load Balancer DNS name = " + lb.dnsName());
}
}
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/elastic-load-balancing-v2#code-examples).
```
import {
ElasticLoadBalancingV2Client,
DescribeLoadBalancersCommand,
} from "@aws-sdk/client-elastic-load-balancing-v2";
export async function main() {
const client = new ElasticLoadBalancingV2Client({});
const { LoadBalancers } = await client.send(
new DescribeLoadBalancersCommand({}),
);
const loadBalancersList = LoadBalancers.map(
(lb) => `• ${lb.LoadBalancerName}: ${lb.DNSName}`,
).join("\n");
console.log(
"Hello, Elastic Load Balancing! Let's list some of your load balancers:\n",
loadBalancersList,
);
}
// Call function if run directly
import { fileURLToPath } from "node:url";
if (process.argv[1] === fileURLToPath(import.meta.url)) {
main();
}
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DescribeLoadBalancersCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
import boto3
def hello_elbv2(elbv2_client):
"""
Use the AWS SDK for Python (Boto3) to create an Elastic Load Balancing V2 client and list
up to ten of the load balancers for your account.
This example uses the default settings specified in your shared credentials
and config files.
:param elbv2_client: A Boto3 Elastic Load Balancing V2 client object.
"""
print("Hello, Elastic Load Balancing! Let's list some of your load balancers:")
load_balancers = elbv2_client.describe_load_balancers(PageSize=10).get(
"LoadBalancers", []
)
if load_balancers:
for lb in load_balancers:
print(f"\t{lb['LoadBalancerName']}: {lb['DNSName']}")
else:
print("Your account doesn't have any load balancers.")
if __name__ == "__main__":
hello_elbv2(boto3.client("elbv2"))
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers) in *AWS SDK for Python (Boto3) API Reference*.
------
# Actions for Elastic Load Balancing - Version 2 using AWS SDKs
The following code examples demonstrate how to perform individual Elastic Load Balancing - Version 2 actions with AWS SDKs. Each example includes a link to GitHub, where you can find instructions for setting up and running the code.
These excerpts call the Elastic Load Balancing - Version 2 API and are code excerpts from larger programs that must be run in context. You can see actions in context in [Scenarios for Elastic Load Balancing - Version 2 using AWS SDKs](elastic-load-balancing-v2_code_examples_scenarios.md).
The following examples include only the most commonly used actions. For a complete list, see the [Elastic Load Balancing - Version 2 API Reference](https://docs.aws.amazon.com/elasticloadbalancing/latest/APIReference/Welcome.html).
**Topics**
+ [`AddListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_AddListenerCertificates_section.md)
+ [`AddTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_AddTags_section.md)
+ [`CreateListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateListener_section.md)
+ [`CreateLoadBalancer`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateLoadBalancer_section.md)
+ [`CreateRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateRule_section.md)
+ [`CreateTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_CreateTargetGroup_section.md)
+ [`DeleteListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteListener_section.md)
+ [`DeleteLoadBalancer`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteLoadBalancer_section.md)
+ [`DeleteRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteRule_section.md)
+ [`DeleteTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeleteTargetGroup_section.md)
+ [`DeregisterTargets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DeregisterTargets_section.md)
+ [`DescribeAccountLimits`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeAccountLimits_section.md)
+ [`DescribeListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeListenerCertificates_section.md)
+ [`DescribeListeners`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeListeners_section.md)
+ [`DescribeLoadBalancerAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeLoadBalancerAttributes_section.md)
+ [`DescribeLoadBalancers`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeLoadBalancers_section.md)
+ [`DescribeRules`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeRules_section.md)
+ [`DescribeSslPolicies`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeSslPolicies_section.md)
+ [`DescribeTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTags_section.md)
+ [`DescribeTargetGroupAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetGroupAttributes_section.md)
+ [`DescribeTargetGroups`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetGroups_section.md)
+ [`DescribeTargetHealth`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_DescribeTargetHealth_section.md)
+ [`ModifyListener`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyListener_section.md)
+ [`ModifyLoadBalancerAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyLoadBalancerAttributes_section.md)
+ [`ModifyRule`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyRule_section.md)
+ [`ModifyTargetGroup`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyTargetGroup_section.md)
+ [`ModifyTargetGroupAttributes`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_ModifyTargetGroupAttributes_section.md)
+ [`RegisterTargets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RegisterTargets_section.md)
+ [`RemoveListenerCertificates`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RemoveListenerCertificates_section.md)
+ [`RemoveTags`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_RemoveTags_section.md)
+ [`SetIpAddressType`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetIpAddressType_section.md)
+ [`SetRulePriorities`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetRulePriorities_section.md)
+ [`SetSecurityGroups`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetSecurityGroups_section.md)
+ [`SetSubnets`](elastic-load-balancing-v2_example_elastic-load-balancing-v2_SetSubnets_section.md)
# Use `AddListenerCertificates` with a CLI
The following code examples show how to use `AddListenerCertificates`.
------
#### [ CLI ]
**AWS CLI**
**To add a certificate to a secure listener**
This example adds the specified certificate to the specified secure listener.
Command:
```
aws elbv2 add-listener-certificates --listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 --certificates CertificateArn=arn:aws:acm:us-west-2:123456789012:certificate/5cc54884-f4a3-4072-80be-05b9ba72f705
```
Output:
```
{
"Certificates": [
{
"CertificateArn": "arn:aws:acm:us-west-2:123456789012:certificate/5cc54884-f4a3-4072-80be-05b9ba72f705",
"IsDefault": false
}
]
}
```
+ For API details, see [AddListenerCertificates](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/add-listener-certificates.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example adds additional certificate to the specified Listener.**
```
Add-ELB2ListenerCertificate -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618' -Certificate @{CertificateArn = 'arn:aws:acm:us-east-1:123456789012:certificate/19478bd5-491d-47d4-b1d7-5217feba1d97'}
```
**Output:**
```
CertificateArn IsDefault
-------------- ---------
arn:aws:acm:us-east-1:123456789012:certificate/19478bd5-491d-47d4-b1d7-5217feba1d97 False
```
+ For API details, see [AddListenerCertificates](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example adds additional certificate to the specified Listener.**
```
Add-ELB2ListenerCertificate -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618' -Certificate @{CertificateArn = 'arn:aws:acm:us-east-1:123456789012:certificate/19478bd5-491d-47d4-b1d7-5217feba1d97'}
```
**Output:**
```
CertificateArn IsDefault
-------------- ---------
arn:aws:acm:us-east-1:123456789012:certificate/19478bd5-491d-47d4-b1d7-5217feba1d97 False
```
+ For API details, see [AddListenerCertificates](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `AddTags` with a CLI
The following code examples show how to use `AddTags`.
------
#### [ CLI ]
**AWS CLI**
**To add tags to a load balancer**
The following `add-tags` example adds the `project` and `department` tags to the specified load balancer.
```
aws elbv2 add-tags \
--resource-arns arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 \
--tags "Key=project,Value=lima" "Key=department,Value=digital-media"
```
+ For API details, see [AddTags](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/add-tags.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example add new Tag to specified `AWS.Tools.ElasticLoadBalancingV2` resource.**
```
Add-ELB2Tag -ResourceArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -Tag @{Key = 'productVersion'; Value = '1.0.0'}
```
+ For API details, see [AddTags](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example add new Tag to specified `AWS.Tools.ElasticLoadBalancingV2` resource.**
```
Add-ELB2Tag -ResourceArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -Tag @{Key = 'productVersion'; Value = '1.0.0'}
```
+ For API details, see [AddTags](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `CreateListener` with an AWS SDK or CLI
The following code examples show how to use `CreateListener`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService/ElasticLoadBalancerActions#code-examples).
```
///
/// Create an Elastic Load Balancing load balancer that uses the specified subnets
/// and forwards requests to the specified target group.
///
/// The name for the new load balancer.
/// Subnets for the load balancer.
/// Target group for forwarded requests.
/// The new LoadBalancer object.
public async Task CreateLoadBalancerAndListener(string name, List subnetIds, TargetGroup targetGroup)
{
var createLbResponse = await _amazonElasticLoadBalancingV2.CreateLoadBalancerAsync(
new CreateLoadBalancerRequest()
{
Name = name,
Subnets = subnetIds
});
var loadBalancerArn = createLbResponse.LoadBalancers[0].LoadBalancerArn;
// Wait for load balancer to be available.
var loadBalancerReady = false;
while (!loadBalancerReady)
{
try
{
var describeResponse =
await _amazonElasticLoadBalancingV2.DescribeLoadBalancersAsync(
new DescribeLoadBalancersRequest()
{
Names = new List() { name }
});
var loadBalancerState = describeResponse.LoadBalancers[0].State.Code;
loadBalancerReady = loadBalancerState == LoadBalancerStateEnum.Active;
}
catch (LoadBalancerNotFoundException)
{
loadBalancerReady = false;
}
Thread.Sleep(10000);
}
// Create the listener.
await _amazonElasticLoadBalancingV2.CreateListenerAsync(
new CreateListenerRequest()
{
LoadBalancerArn = loadBalancerArn,
Protocol = targetGroup.Protocol,
Port = targetGroup.Port,
DefaultActions = new List()
{
new Action()
{
Type = ActionTypeEnum.Forward,
TargetGroupArn = targetGroup.TargetGroupArn
}
}
});
return createLbResponse.LoadBalancers[0];
}
```
+ For API details, see [CreateListener](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/CreateListener) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To create an HTTP listener**
The following `create-listener` example creates an HTTP listener for the specified Application Load Balancer that forwards requests to the specified target group.
```
aws elbv2 create-listener \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 \
--protocol HTTP \
--port 80 \
--default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
For more information, see [Tutorial: Create an Application Load Balancer using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/tutorial-application-load-balancer-cli.html#create-load-balancer-aws-cli) in the *User Guide for Application Load Balancers*.
**Example 2: To create an HTTPS listener**
The following `create-listener` example creates an HTTPS listener for the specified Application Load Balancer that forwards requests to the specified target group. You must specify an SSL certificate for an HTTPS listener. You can create and manage certificates using AWS Certificate Manager (ACM). Alternatively, you can create a certificate using SSL/TLS tools, get the certificate signed by a certificate authority (CA), and upload the certificate to AWS Identity and Access Management (IAM).
```
aws elbv2 create-listener \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 \
--protocol HTTPS \
--port 443 \
--certificates CertificateArn=arn:aws:acm:us-west-2:123456789012:certificate/3dcb0a41-bd72-4774-9ad9-756919c40557 \
--ssl-policy ELBSecurityPolicy-2016-08 \
--default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
For more information, see [Add an HTTPS listener](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/tutorial-application-load-balancer-cli.html#https-listener-aws-cli) in the *User Guide for Application Load Balancers*.
**Example 3: To create a TCP listener**
The following `create-listener` example creates a TCP listener for the specified Network Load Balancer that forwards requests to the specified target group.
```
aws elbv2 create-listener \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/net/my-network-load-balancer/5d1b75f4f1cee11e \
--protocol TCP \
--port 80 \
--default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-tcp-targets/b6bba954d1361c78
```
For more information, see [Tutorial: Create a Network Load Balancer using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/network/network-load-balancer-cli.html#create-load-balancer-aws-cli) in the *User Guide for Network Load Balancers*.
**Example 4: To create a TLS listener**
The following `create-listener` example creates a TLS listener for the specified Network Load Balancer that forwards requests to the specified target group. You must specify an SSL certificate for a TLS listener.
```
aws elbv2 create-listener \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 \
--protocol TLS \
--port 443 \
--certificates CertificateArn=arn:aws:acm:us-west-2:123456789012:certificate/3dcb0a41-bd72-4774-9ad9-756919c40557 \
--ssl-policy ELBSecurityPolicy-2016-08 \
--default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
For more information, see [TLS listeners for your Network Load Balancer](https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-tls-listener.html) in the *User Guide for Network Load Balancers*.
**Example 5: To create a UDP listener**
The following `create-listener` example creates a UDP listener for the specified Network Load Balancer that forwards requests to the specified target group.
```
aws elbv2 create-listener \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/net/my-network-load-balancer/5d1b75f4f1cee11e \
--protocol UDP \
--port 53 \
--default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-tcp-targets/b6bba954d1361c78
```
For more information, see [Tutorial: Create a Network Load Balancer using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/network/network-load-balancer-cli.html#create-load-balancer-aws-cli) in the *User Guide for Network Load Balancers*.
**Example 6: To create a listener for the specified gateway and forwarding**
The following `create-listener` example creates a listener for the specified Gateway Load Balancer that forwards requests to the specified target group.
```
aws elbv2 create-listener \
--load-balancer-arn arn:aws:elasticloadbalancing:us-east-1:850631746142:loadbalancer/gwy/my-gateway-load-balancer/e0f9b3d5c7f7d3d6 \
--default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-east-1:850631746142:targetgroup/my-glb-targets/007ca469fae3bb1615
```
Output:
```
{
"Listeners": [
{
"ListenerArn": "arn:aws:elasticloadbalancing:us-east-1:850631746142:listener/gwy/my-agw-lb-example2/e0f9b3d5c7f7d3d6/afc127db15f925de",
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-east-1:850631746142:loadbalancer/gwy/my-agw-lb-example2/e0f9b3d5c7f7d3d6",
"DefaultActions": [
{
"Type": "forward",
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-east-1:850631746142:targetgroup/test-tg-agw-2/007ca469fae3bb1615",
"ForwardConfig": {
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-east-1:850631746142:targetgroup/test-tg-agw-2/007ca469fae3bb1615"
}
]
}
}
]
}
]
}
```
For more information, see [Getting started with Gateway Load Balancers using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/gateway/getting-started-cli.html) in the *User Guide for Gateway Load Balancers*.
+ For API details, see [CreateListener](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/create-listener.html) in *AWS CLI Command Reference*.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
```
/*
* Creates an Elastic Load Balancing load balancer that uses the specified
* subnets
* and forwards requests to the specified target group.
*/
public String createLoadBalancer(List subnetIds, String targetGroupARN, String lbName, int port,
String protocol) {
try {
List subnetIdStrings = subnetIds.stream()
.map(Subnet::subnetId)
.collect(Collectors.toList());
CreateLoadBalancerRequest balancerRequest = CreateLoadBalancerRequest.builder()
.subnets(subnetIdStrings)
.name(lbName)
.scheme("internet-facing")
.build();
// Create and wait for the load balancer to become available.
CreateLoadBalancerResponse lsResponse = getLoadBalancerClient().createLoadBalancer(balancerRequest);
String lbARN = lsResponse.loadBalancers().get(0).loadBalancerArn();
ElasticLoadBalancingV2Waiter loadBalancerWaiter = getLoadBalancerClient().waiter();
DescribeLoadBalancersRequest request = DescribeLoadBalancersRequest.builder()
.loadBalancerArns(lbARN)
.build();
System.out.println("Waiting for Load Balancer " + lbName + " to become available.");
WaiterResponse waiterResponse = loadBalancerWaiter
.waitUntilLoadBalancerAvailable(request);
waiterResponse.matched().response().ifPresent(System.out::println);
System.out.println("Load Balancer " + lbName + " is available.");
// Get the DNS name (endpoint) of the load balancer.
String lbDNSName = lsResponse.loadBalancers().get(0).dnsName();
System.out.println("*** Load Balancer DNS Name: " + lbDNSName);
// Create a listener for the load balance.
Action action = Action.builder()
.targetGroupArn(targetGroupARN)
.type("forward")
.build();
CreateListenerRequest listenerRequest = CreateListenerRequest.builder()
.loadBalancerArn(lsResponse.loadBalancers().get(0).loadBalancerArn())
.defaultActions(action)
.port(port)
.protocol(protocol)
.build();
getLoadBalancerClient().createListener(listenerRequest);
System.out.println("Created listener to forward traffic from load balancer " + lbName + " to target group "
+ targetGroupARN);
// Return the load balancer DNS name.
return lbDNSName;
} catch (ElasticLoadBalancingV2Exception e) {
e.printStackTrace();
}
return "";
}
```
+ For API details, see [CreateListener](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/CreateListener) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-resilient-service#code-examples).
```
const client = new ElasticLoadBalancingV2Client({});
const { Listeners } = await client.send(
new CreateListenerCommand({
LoadBalancerArn: state.loadBalancerArn,
Protocol: state.targetGroupProtocol,
Port: state.targetGroupPort,
DefaultActions: [
{ Type: "forward", TargetGroupArn: state.targetGroupArn },
],
}),
);
```
+ For API details, see [CreateListener](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/CreateListenerCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example creates new ALB listener with the default action 'Forward' to send traffic to specified Target Group.**
```
$defaultAction = [Amazon.ElasticLoadBalancingV2.Model.Action]@{
ForwardConfig = @{
TargetGroups = @(
@{ TargetGroupArn = "arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/testAlbTG/3d61c2f20aa5bccb" }
)
TargetGroupStickinessConfig = @{
DurationSeconds = 900
Enabled = $true
}
}
Type = "Forward"
}
New-ELB2Listener -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/testALB/3e2f03b558e19676' -Port 8001 -Protocol "HTTP" -DefaultAction $defaultAction
```
**Output:**
```
Certificates : {}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/1c84f02aec143e80
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/testALB/3e2f03b558e19676
Port : 8001
Protocol : HTTP
SslPolicy :
```
+ For API details, see [CreateListener](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example creates new ALB listener with the default action 'Forward' to send traffic to specified Target Group.**
```
$defaultAction = [Amazon.ElasticLoadBalancingV2.Model.Action]@{
ForwardConfig = @{
TargetGroups = @(
@{ TargetGroupArn = "arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/testAlbTG/3d61c2f20aa5bccb" }
)
TargetGroupStickinessConfig = @{
DurationSeconds = 900
Enabled = $true
}
}
Type = "Forward"
}
New-ELB2Listener -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/testALB/3e2f03b558e19676' -Port 8001 -Protocol "HTTP" -DefaultAction $defaultAction
```
**Output:**
```
Certificates : {}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/1c84f02aec143e80
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/testALB/3e2f03b558e19676
Port : 8001
Protocol : HTTP
SslPolicy :
```
+ For API details, see [CreateListener](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def create_listener(
self,
load_balancer_name: str,
target_group: Dict[str, Any],
) -> Dict[str, Any]:
"""
Creates a listener for the specified load balancer that forwards requests to the
specified target group.
:param load_balancer_name: The name of the load balancer to create a listener for.
:param target_group: An existing target group that is added as a listener to the
load balancer.
:return: Data about the newly created listener.
"""
try:
# Retrieve the load balancer ARN
load_balancer_response = self.elb_client.describe_load_balancers(
Names=[load_balancer_name]
)
load_balancer_arn = load_balancer_response["LoadBalancers"][0][
"LoadBalancerArn"
]
# Create the listener
response = self.elb_client.create_listener(
LoadBalancerArn=load_balancer_arn,
Protocol=target_group["Protocol"],
Port=target_group["Port"],
DefaultActions=[
{
"Type": "forward",
"TargetGroupArn": target_group["TargetGroupArn"],
}
],
)
log.info(
f"Created listener to forward traffic from load balancer '{load_balancer_name}' to target group '{target_group['TargetGroupName']}'."
)
return response["Listeners"][0]
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to add a listener on '{load_balancer_name}' for target group '{target_group['TargetGroupName']}'."
)
if error_code == "ListenerNotFoundException":
log.error(
f"The listener could not be found for the load balancer '{load_balancer_name}'. "
"Please check the load balancer name and target group configuration."
)
if error_code == "InvalidConfigurationRequestException":
log.error(
f"The configuration provided for the listener on load balancer '{load_balancer_name}' is invalid. "
"Please review the provided protocol, port, and target group settings."
)
log.error(f"Full error:\n\t{err}")
```
+ For API details, see [CreateListener](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/CreateListener) in *AWS SDK for Python (Boto3) API Reference*.
------
# Use `CreateLoadBalancer` with an AWS SDK or CLI
The following code examples show how to use `CreateLoadBalancer`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService/ElasticLoadBalancerActions#code-examples).
```
///
/// Create an Elastic Load Balancing load balancer that uses the specified subnets
/// and forwards requests to the specified target group.
///
/// The name for the new load balancer.
/// Subnets for the load balancer.
/// Target group for forwarded requests.
/// The new LoadBalancer object.
public async Task CreateLoadBalancerAndListener(string name, List subnetIds, TargetGroup targetGroup)
{
var createLbResponse = await _amazonElasticLoadBalancingV2.CreateLoadBalancerAsync(
new CreateLoadBalancerRequest()
{
Name = name,
Subnets = subnetIds
});
var loadBalancerArn = createLbResponse.LoadBalancers[0].LoadBalancerArn;
// Wait for load balancer to be available.
var loadBalancerReady = false;
while (!loadBalancerReady)
{
try
{
var describeResponse =
await _amazonElasticLoadBalancingV2.DescribeLoadBalancersAsync(
new DescribeLoadBalancersRequest()
{
Names = new List() { name }
});
var loadBalancerState = describeResponse.LoadBalancers[0].State.Code;
loadBalancerReady = loadBalancerState == LoadBalancerStateEnum.Active;
}
catch (LoadBalancerNotFoundException)
{
loadBalancerReady = false;
}
Thread.Sleep(10000);
}
// Create the listener.
await _amazonElasticLoadBalancingV2.CreateListenerAsync(
new CreateListenerRequest()
{
LoadBalancerArn = loadBalancerArn,
Protocol = targetGroup.Protocol,
Port = targetGroup.Port,
DefaultActions = new List()
{
new Action()
{
Type = ActionTypeEnum.Forward,
TargetGroupArn = targetGroup.TargetGroupArn
}
}
});
return createLbResponse.LoadBalancers[0];
}
```
+ For API details, see [CreateLoadBalancer](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/CreateLoadBalancer) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To create an Internet-facing load balancer**
The following `create-load-balancer` example creates an Internet-facing Application Load Balancer and enables the Availability Zones for the specified subnets.
```
aws elbv2 create-load-balancer \
--name my-load-balancer \
--subnets subnet-b7d581c0 subnet-8360a9e7
```
Output:
```
{
"LoadBalancers": [
{
"Type": "application",
"Scheme": "internet-facing",
"IpAddressType": "ipv4",
"VpcId": "vpc-3ac0fb5f",
"AvailabilityZones": [
{
"ZoneName": "us-west-2a",
"SubnetId": "subnet-8360a9e7"
},
{
"ZoneName": "us-west-2b",
"SubnetId": "subnet-b7d581c0"
}
],
"CreatedTime": "2017-08-25T21:26:12.920Z",
"CanonicalHostedZoneId": "Z2P70J7EXAMPLE",
"DNSName": "my-load-balancer-424835706.us-west-2.elb.amazonaws.com",
"SecurityGroups": [
"sg-5943793c"
],
"LoadBalancerName": "my-load-balancer",
"State": {
"Code": "provisioning"
},
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188"
}
]
}
```
For more information, see [Tutorial: Create an Application Load Balancer using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/tutorial-application-load-balancer-cli.html) in the *User Guide for Application Load Balancers*.
**Example 2: To create an internal load balancer**
The following `create-load-balancer` example creates an internal Application Load Balancer and enables the Availability Zones for the specified subnets.
```
aws elbv2 create-load-balancer \
--name my-internal-load-balancer \
--scheme internal \
--subnets subnet-b7d581c0 subnet-8360a9e7
```
Output:
```
{
"LoadBalancers": [
{
"Type": "application",
"Scheme": "internal",
"IpAddressType": "ipv4",
"VpcId": "vpc-3ac0fb5f",
"AvailabilityZones": [
{
"ZoneName": "us-west-2a",
"SubnetId": "subnet-8360a9e7"
},
{
"ZoneName": "us-west-2b",
"SubnetId": "subnet-b7d581c0"
}
],
"CreatedTime": "2016-03-25T21:29:48.850Z",
"CanonicalHostedZoneId": "Z2P70J7EXAMPLE",
"DNSName": "internal-my-internal-load-balancer-1529930873.us-west-2.elb.amazonaws.com",
"SecurityGroups": [
"sg-5943793c"
],
"LoadBalancerName": "my-internal-load-balancer",
"State": {
"Code": "provisioning"
},
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-internal-load-balancer/5b49b8d4303115c2"
}
]
}
```
For more information, see [Tutorial: Create an Application Load Balancer using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/tutorial-application-load-balancer-cli.html) in the *User Guide for Application Load Balancers*.
**Example 3: To create a Network Load Balancer**
The following `create-load-balancer` example creates an Internet-facing Network Load Balancer and enables the Availability Zone for the specified subnet. It uses a subnet mapping to associate the specified Elastic IP address with the network interface used by the load balancer nodes for the Availability Zone.
```
aws elbv2 create-load-balancer \
--name my-network-load-balancer \
--type network \
--subnet-mappings SubnetId=subnet-b7d581c0,AllocationId=eipalloc-64d5890a
```
Output:
```
{
"LoadBalancers": [
{
"Type": "network",
"Scheme": "internet-facing",
"IpAddressType": "ipv4",
"VpcId": "vpc-3ac0fb5f",
"AvailabilityZones": [
{
"LoadBalancerAddresses": [
{
"IpAddress": "35.161.207.171",
"AllocationId": "eipalloc-64d5890a"
}
],
"ZoneName": "us-west-2b",
"SubnetId": "subnet-5264e837"
}
],
"CreatedTime": "2017-10-15T22:41:25.657Z",
"CanonicalHostedZoneId": "Z2P70J7EXAMPLE",
"DNSName": "my-network-load-balancer-5d1b75f4f1cee11e.elb.us-west-2.amazonaws.com",
"LoadBalancerName": "my-network-load-balancer",
"State": {
"Code": "provisioning"
},
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/net/my-network-load-balancer/5d1b75f4f1cee11e"
}
]
}
```
For more information, see [Tutorial: Create a Network Load Balancer using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/network/network-load-balancer-cli.html) in the *User Guide for Network Load Balancers*.
**Example 4: To create a Gateway Load Balancer**
The following `create-load-balancer` example creates a Gateway Load Balancer and enables the Availability Zones for the specified subnets.
```
aws elbv2 create-load-balancer \
--name my-gateway-load-balancer \
--type gateway \
--subnets subnet-dc83f691 subnet-a62583f9
```
Output:
```
{
"LoadBalancers": [
{
"Type": "gateway",
"VpcId": "vpc-838475fe",
"AvailabilityZones": [
{
"ZoneName": "us-east-1b",
"SubnetId": "subnet-a62583f9"
},
{
"ZoneName": "us-east-1a",
"SubnetId": "subnet-dc83f691"
}
],
"CreatedTime": "2021-07-14T19:33:43.324000+00:00",
"LoadBalancerName": "my-gateway-load-balancer",
"State": {
"Code": "provisioning"
},
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-east-1:850631746142:loadbalancer/gwy/my-gateway-load-balancer/dfbb5a7d32cdee79"
}
]
}
```
For more information, see [Getting started with Gateway Load Balancers using the AWS CLI](https://docs.aws.amazon.com/elasticloadbalancing/latest/gateway/getting-started-cli.html) in the *User Guide for Gateway Load Balancers*.
+ For API details, see [CreateLoadBalancer](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/create-load-balancer.html) in *AWS CLI Command Reference*.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
```
/*
* Creates an Elastic Load Balancing load balancer that uses the specified
* subnets
* and forwards requests to the specified target group.
*/
public String createLoadBalancer(List subnetIds, String targetGroupARN, String lbName, int port,
String protocol) {
try {
List subnetIdStrings = subnetIds.stream()
.map(Subnet::subnetId)
.collect(Collectors.toList());
CreateLoadBalancerRequest balancerRequest = CreateLoadBalancerRequest.builder()
.subnets(subnetIdStrings)
.name(lbName)
.scheme("internet-facing")
.build();
// Create and wait for the load balancer to become available.
CreateLoadBalancerResponse lsResponse = getLoadBalancerClient().createLoadBalancer(balancerRequest);
String lbARN = lsResponse.loadBalancers().get(0).loadBalancerArn();
ElasticLoadBalancingV2Waiter loadBalancerWaiter = getLoadBalancerClient().waiter();
DescribeLoadBalancersRequest request = DescribeLoadBalancersRequest.builder()
.loadBalancerArns(lbARN)
.build();
System.out.println("Waiting for Load Balancer " + lbName + " to become available.");
WaiterResponse waiterResponse = loadBalancerWaiter
.waitUntilLoadBalancerAvailable(request);
waiterResponse.matched().response().ifPresent(System.out::println);
System.out.println("Load Balancer " + lbName + " is available.");
// Get the DNS name (endpoint) of the load balancer.
String lbDNSName = lsResponse.loadBalancers().get(0).dnsName();
System.out.println("*** Load Balancer DNS Name: " + lbDNSName);
// Create a listener for the load balance.
Action action = Action.builder()
.targetGroupArn(targetGroupARN)
.type("forward")
.build();
CreateListenerRequest listenerRequest = CreateListenerRequest.builder()
.loadBalancerArn(lsResponse.loadBalancers().get(0).loadBalancerArn())
.defaultActions(action)
.port(port)
.protocol(protocol)
.build();
getLoadBalancerClient().createListener(listenerRequest);
System.out.println("Created listener to forward traffic from load balancer " + lbName + " to target group "
+ targetGroupARN);
// Return the load balancer DNS name.
return lbDNSName;
} catch (ElasticLoadBalancingV2Exception e) {
e.printStackTrace();
}
return "";
}
```
+ For API details, see [CreateLoadBalancer](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/CreateLoadBalancer) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-resilient-service#code-examples).
```
const client = new ElasticLoadBalancingV2Client({});
const { LoadBalancers } = await client.send(
new CreateLoadBalancerCommand({
Name: NAMES.loadBalancerName,
Subnets: state.subnets,
}),
);
state.loadBalancerDns = LoadBalancers[0].DNSName;
state.loadBalancerArn = LoadBalancers[0].LoadBalancerArn;
await waitUntilLoadBalancerAvailable(
{ client },
{ Names: [NAMES.loadBalancerName] },
);
```
+ For API details, see [CreateLoadBalancer](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/CreateLoadBalancerCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example creates new internet facing Application load balancer with two subnets.**
```
New-ELB2LoadBalancer -Type application -Scheme internet-facing -IpAddressType ipv4 -Name 'New-Test-ALB' -SecurityGroup 'sg-07c3414abb8811cbd' -subnet 'subnet-c37a67a6','subnet-fc02eea0'
```
**Output:**
```
AvailabilityZones : {us-east-1b, us-east-1a}
CanonicalHostedZoneId : Z35SXDOTRQ7X7K
CreatedTime : 12/28/19 2:58:03 PM
DNSName : New-Test-ALB-1391502222.us-east-1.elb.amazonaws.com
IpAddressType : ipv4
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/New-Test-ALB/dab2e4d90eb51493
LoadBalancerName : New-Test-ALB
Scheme : internet-facing
SecurityGroups : {sg-07c3414abb8811cbd}
State : Amazon.ElasticLoadBalancingV2.Model.LoadBalancerState
Type : application
VpcId : vpc-2cfd7000
```
+ For API details, see [CreateLoadBalancer](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example creates new internet facing Application load balancer with two subnets.**
```
New-ELB2LoadBalancer -Type application -Scheme internet-facing -IpAddressType ipv4 -Name 'New-Test-ALB' -SecurityGroup 'sg-07c3414abb8811cbd' -subnet 'subnet-c37a67a6','subnet-fc02eea0'
```
**Output:**
```
AvailabilityZones : {us-east-1b, us-east-1a}
CanonicalHostedZoneId : Z35SXDOTRQ7X7K
CreatedTime : 12/28/19 2:58:03 PM
DNSName : New-Test-ALB-1391502222.us-east-1.elb.amazonaws.com
IpAddressType : ipv4
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/New-Test-ALB/dab2e4d90eb51493
LoadBalancerName : New-Test-ALB
Scheme : internet-facing
SecurityGroups : {sg-07c3414abb8811cbd}
State : Amazon.ElasticLoadBalancingV2.Model.LoadBalancerState
Type : application
VpcId : vpc-2cfd7000
```
+ For API details, see [CreateLoadBalancer](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def create_load_balancer(
self,
load_balancer_name: str,
subnet_ids: List[str],
) -> Dict[str, Any]:
"""
Creates an Elastic Load Balancing load balancer that uses the specified subnets
and forwards requests to the specified target group.
:param load_balancer_name: The name of the load balancer to create.
:param subnet_ids: A list of subnets to associate with the load balancer.
:return: Data about the newly created load balancer.
"""
try:
response = self.elb_client.create_load_balancer(
Name=load_balancer_name, Subnets=subnet_ids
)
load_balancer = response["LoadBalancers"][0]
log.info(f"Created load balancer '{load_balancer_name}'.")
waiter = self.elb_client.get_waiter("load_balancer_available")
log.info(
f"Waiting for load balancer '{load_balancer_name}' to be available..."
)
waiter.wait(Names=[load_balancer_name])
log.info(f"Load balancer '{load_balancer_name}' is now available!")
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to create load balancer '{load_balancer_name}'. Error code: {error_code}, Message: {err.response['Error']['Message']}"
)
if error_code == "DuplicateLoadBalancerNameException":
log.error(
f"A load balancer with the name '{load_balancer_name}' already exists. "
"Load balancer names must be unique within the AWS region. "
"Please choose a different name and try again."
)
if error_code == "TooManyLoadBalancersException":
log.error(
"The maximum number of load balancers has been reached in this account and region. "
"You can delete unused load balancers or request an increase in the service quota from AWS Support."
)
log.error(f"Full error:\n\t{err}")
else:
return load_balancer
```
+ For API details, see [CreateLoadBalancer](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/CreateLoadBalancer) in *AWS SDK for Python (Boto3) API Reference*.
------
# Use `CreateRule` with a CLI
The following code examples show how to use `CreateRule`.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To create a rule using a path condition and a forward action**
The following `create-rule` example creates a rule that forwards requests to the specified target group if the URL contains the specified pattern.
```
aws elbv2 create-rule \
--listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 \
--priority 5 \
--conditions file://conditions-pattern.json
--actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
Contents of `conditions-pattern.json`:
```
[
{
"Field": "path-pattern",
"PathPatternConfig": {
"Values": ["/images/*"]
}
}
]
```
**Example 2: To create a rule using a host condition and a fixed response**
The following `create-rule` example creates a rule that provides a fixed response if the hostname in the host header matches the specified hostname.
```
aws elbv2 create-rule \
--listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 \
--priority 10 \
--conditions file://conditions-host.json \
--actions file://actions-fixed-response.json
```
Contents of `conditions-host.json`
```
[
{
"Field": "host-header",
"HostHeaderConfig": {
"Values": ["*.example.com"]
}
}
]
```
Contents of `actions-fixed-response.json`
```
[
{
"Type": "fixed-response",
"FixedResponseConfig": {
"MessageBody": "Hello world",
"StatusCode": "200",
"ContentType": "text/plain"
}
}
]
```
**Example 3: To create a rule using a source IP address condition, an authenticate action, and a forward action**
The following `create-rule` example creates a rule that authenticates the user if the source IP address matches the specified IP address, and forwards the request to the specified target group if authentication is successful.
```
aws elbv2 create-rule \
--listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 \
--priority 20 \
--conditions file://conditions-source-ip.json \
--actions file://actions-authenticate.json
```
Contents of `conditions-source-ip.json`
```
[
{
"Field": "source-ip",
"SourceIpConfig": {
"Values": ["192.0.2.0/24", "198.51.100.10/32"]
}
}
]
```
Contents of `actions-authenticate.json`
```
[
{
"Type": "authenticate-oidc",
"AuthenticateOidcConfig": {
"Issuer": "https://idp-issuer.com",
"AuthorizationEndpoint": "https://authorization-endpoint.com",
"TokenEndpoint": "https://token-endpoint.com",
"UserInfoEndpoint": "https://user-info-endpoint.com",
"ClientId": "abcdefghijklmnopqrstuvwxyz123456789",
"ClientSecret": "123456789012345678901234567890",
"SessionCookieName": "my-cookie",
"SessionTimeout": 3600,
"Scope": "email",
"AuthenticationRequestExtraParams": {
"display": "page",
"prompt": "login"
},
"OnUnauthenticatedRequest": "deny"
},
"Order": 1
},
{
"Type": "forward",
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-east-1:880185128111:targetgroup/cli-test/642a97ecb0e0f26b",
"Order": 2
}
]
```
+ For API details, see [CreateRule](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/create-rule.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example creates new Listener rule with fixed-response action based on the customer header value for the specified Listener.**
```
$newRuleAction = [Amazon.ElasticLoadBalancingV2.Model.Action]@{
"FixedResponseConfig" = @{
"ContentType" = "text/plain"
"MessageBody" = "Hello World"
"StatusCode" = "200"
}
"Type" = [Amazon.ElasticLoadBalancingV2.ActionTypeEnum]::FixedResponse
}
$newRuleCondition = [Amazon.ElasticLoadBalancingV2.Model.RuleCondition]@{
"httpHeaderConfig" = @{
"HttpHeaderName" = "customHeader"
"Values" = "header2","header1"
}
"Field" = "http-header"
}
New-ELB2Rule -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/1c84f02aec143e80' -Action $newRuleAction -Condition $newRuleCondition -Priority 10
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 10
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/testALB/3e2f03b558e19676/1c84f02aec143e80/f4f51dfaa033a8cc
```
+ For API details, see [CreateRule](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example creates new Listener rule with fixed-response action based on the customer header value for the specified Listener.**
```
$newRuleAction = [Amazon.ElasticLoadBalancingV2.Model.Action]@{
"FixedResponseConfig" = @{
"ContentType" = "text/plain"
"MessageBody" = "Hello World"
"StatusCode" = "200"
}
"Type" = [Amazon.ElasticLoadBalancingV2.ActionTypeEnum]::FixedResponse
}
$newRuleCondition = [Amazon.ElasticLoadBalancingV2.Model.RuleCondition]@{
"httpHeaderConfig" = @{
"HttpHeaderName" = "customHeader"
"Values" = "header2","header1"
}
"Field" = "http-header"
}
New-ELB2Rule -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/1c84f02aec143e80' -Action $newRuleAction -Condition $newRuleCondition -Priority 10
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 10
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/testALB/3e2f03b558e19676/1c84f02aec143e80/f4f51dfaa033a8cc
```
+ For API details, see [CreateRule](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `CreateTargetGroup` with an AWS SDK or CLI
The following code examples show how to use `CreateTargetGroup`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService/ElasticLoadBalancerActions#code-examples).
```
///
/// Create an Elastic Load Balancing target group. The target group specifies how the load balancer forwards
/// requests to instances in the group and how instance health is checked.
///
/// To speed up this demo, the health check is configured with shortened times and lower thresholds. In production,
/// you might want to decrease the sensitivity of your health checks to avoid unwanted failures.
///
/// The name for the group.
/// The protocol, such as HTTP.
/// The port to use to forward requests, such as 80.
/// The Id of the Vpc in which the load balancer exists.
/// The new TargetGroup object.
public async Task CreateTargetGroupOnVpc(string groupName, ProtocolEnum protocol, int port, string vpcId)
{
var createResponse = await _amazonElasticLoadBalancingV2.CreateTargetGroupAsync(
new CreateTargetGroupRequest()
{
Name = groupName,
Protocol = protocol,
Port = port,
HealthCheckPath = "/healthcheck",
HealthCheckIntervalSeconds = 10,
HealthCheckTimeoutSeconds = 5,
HealthyThresholdCount = 2,
UnhealthyThresholdCount = 2,
VpcId = vpcId
});
var targetGroup = createResponse.TargetGroups[0];
return targetGroup;
}
```
+ For API details, see [CreateTargetGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/CreateTargetGroup) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To create a target group for an Application Load Balancer**
The following `create-target-group` example creates a target group for an Application Load Balancer where you register targets by instance ID (the target type is `instance`). This target group uses the HTTP protocol, port 80, and the default health check settings for an HTTP target group.
```
aws elbv2 create-target-group \
--name my-targets \
--protocol HTTP \
--port 80 \
--target-type instance \
--vpc-id vpc-3ac0fb5f
```
Output:
```
{
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
"TargetGroupName": "my-targets",
"Protocol": "HTTP",
"Port": 80,
"VpcId": "vpc-3ac0fb5f",
"HealthCheckProtocol": "HTTP",
"HealthCheckPort": "traffic-port",
"HealthCheckEnabled": true,
"HealthCheckIntervalSeconds": 30,
"HealthCheckTimeoutSeconds": 5,
"HealthyThresholdCount": 5,
"UnhealthyThresholdCount": 2,
"HealthCheckPath": "/",
"Matcher": {
"HttpCode": "200"
},
"TargetType": "instance",
"ProtocolVersion": "HTTP1",
"IpAddressType": "ipv4"
}
]
}
```
For more information, see [Create a target group](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/create-target-group.html) in the *User Guide for Application Load Balancers*.
**Example 2: To create a target group to route traffic from an Application Load Balancer to a Lambda function**
The following `create-target-group` example creates a target group for an Application Load Balancer where the target is a Lambda function (the target type is `lambda`). Health checks are disabled for this target group by default.
```
aws elbv2 create-target-group \
--name my-lambda-target \
--target-type lambda
```
Output:
```
{
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-lambda-target/a3003e085dbb8ddc",
"TargetGroupName": "my-lambda-target",
"HealthCheckEnabled": false,
"HealthCheckIntervalSeconds": 35,
"HealthCheckTimeoutSeconds": 30,
"HealthyThresholdCount": 5,
"UnhealthyThresholdCount": 2,
"HealthCheckPath": "/",
"Matcher": {
"HttpCode": "200"
},
"TargetType": "lambda",
"IpAddressType": "ipv4"
}
]
}
```
For more information, see [Lambda functions as targets](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/lambda-functions.html) in the *User Guide for Application Load Balancers*.
**Example 3: To create a target group for a Network Load Balancer**
The following `create-target-group` example creates a target group for a Network Load Balancer where you register targets by IP address (the target type is `ip`). This target group uses the TCP protocol, port 80, and the default health check settings for a TCP target group.
```
aws elbv2 create-target-group \
--name my-ip-targets \
--protocol TCP \
--port 80 \
--target-type ip \
--vpc-id vpc-3ac0fb5f
```
Output:
```
{
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-ip-targets/b6bba954d1361c78",
"TargetGroupName": "my-ip-targets",
"Protocol": "TCP",
"Port": 80,
"VpcId": "vpc-3ac0fb5f",
"HealthCheckEnabled": true,
"HealthCheckProtocol": "TCP",
"HealthCheckPort": "traffic-port",
"HealthCheckIntervalSeconds": 30,
"HealthCheckTimeoutSeconds": 10,
"HealthyThresholdCount": 5,
"UnhealthyThresholdCount": 2,
"TargetType": "ip",
"IpAddressType": "ipv4"
}
]
}
```
For more information, see [Create a target group](https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-target-group.html) in the *User Guide for Network Load Balancers*.
**Example 4: To create a target group to route traffic from a Network Load Balancer to an Application Load Balancer**
The following `create-target-group` example creates a target group for a Network Load Balancer where you register an Application Load Balancer as a target (the target type is `alb`).
aws elbv2 create-target-group --name my-alb-target --protocol TCP --port 80 --target-type alb --vpc-id vpc-3ac0fb5f
Output:
```
{
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-alb-target/a3003e085dbb8ddc",
"TargetGroupName": "my-alb-target",
"Protocol": "TCP",
"Port": 80,
"VpcId": "vpc-838475fe",
"HealthCheckProtocol": "HTTP",
"HealthCheckPort": "traffic-port",
"HealthCheckEnabled": true,
"HealthCheckIntervalSeconds": 30,
"HealthCheckTimeoutSeconds": 6,
"HealthyThresholdCount": 5,
"UnhealthyThresholdCount": 2,
"HealthCheckPath": "/",
"Matcher": {
"HttpCode": "200-399"
},
"TargetType": "alb",
"IpAddressType": "ipv4"
}
]
}
```
For more information, see [Create a target group with an Application Load Balancer as the target](https://docs.aws.amazon.com/elasticloadbalancing/latest/network/application-load-balancer-target.html) in the *User Guide for Network Load Balancers*.
**Example 5: To create a target group for a Gateway Load Balancer**
The following `create-target-group` example creates a target group for a Gateway Load Balancer where the target is an instance, and the target group protocol is `GENEVE`.
```
aws elbv2 create-target-group \
--name my-glb-targetgroup \
--protocol GENEVE \
--port 6081 \
--target-type instance \
--vpc-id vpc-838475fe
```
Output:
```
{
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-glb-targetgroup/00c3d57eacd6f40b6f",
"TargetGroupName": "my-glb-targetgroup",
"Protocol": "GENEVE",
"Port": 6081,
"VpcId": "vpc-838475fe",
"HealthCheckProtocol": "TCP",
"HealthCheckPort": "80",
"HealthCheckEnabled": true,
"HealthCheckIntervalSeconds": 10,
"HealthCheckTimeoutSeconds": 5,
"HealthyThresholdCount": 5,
"UnhealthyThresholdCount": 2,
"TargetType": "instance"
}
]
}
```
For more information, see Create a target group `\$1\$1 in the *Gateway Load Balancer User Guide*.
+ For API details, see [CreateTargetGroup](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/create-target-group.html) in *AWS CLI Command Reference*.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
```
/*
* Creates an Elastic Load Balancing target group. The target group specifies
* how
* the load balancer forward requests to instances in the group and how instance
* health is checked.
*/
public String createTargetGroup(String protocol, int port, String vpcId, String targetGroupName) {
CreateTargetGroupRequest targetGroupRequest = CreateTargetGroupRequest.builder()
.healthCheckPath("/healthcheck")
.healthCheckTimeoutSeconds(5)
.port(port)
.vpcId(vpcId)
.name(targetGroupName)
.protocol(protocol)
.build();
CreateTargetGroupResponse targetGroupResponse = getLoadBalancerClient().createTargetGroup(targetGroupRequest);
String targetGroupArn = targetGroupResponse.targetGroups().get(0).targetGroupArn();
String targetGroup = targetGroupResponse.targetGroups().get(0).targetGroupName();
System.out.println("The " + targetGroup + " was created with ARN" + targetGroupArn);
return targetGroupArn;
}
```
+ For API details, see [CreateTargetGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/CreateTargetGroup) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-resilient-service#code-examples).
```
const client = new ElasticLoadBalancingV2Client({});
const { TargetGroups } = await client.send(
new CreateTargetGroupCommand({
Name: NAMES.loadBalancerTargetGroupName,
Protocol: "HTTP",
Port: 80,
HealthCheckPath: "/healthcheck",
HealthCheckIntervalSeconds: 10,
HealthCheckTimeoutSeconds: 5,
HealthyThresholdCount: 2,
UnhealthyThresholdCount: 2,
VpcId: state.defaultVpc,
}),
);
```
+ For API details, see [CreateTargetGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/CreateTargetGroupCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example creates new Target group with the provided parameters.**
```
New-ELB2TargetGroup -HealthCheckEnabled 1 -HealthCheckIntervalSeconds 30 -HealthCheckPath '/index.html' -HealthCheckPort 80 -HealthCheckTimeoutSecond 5 -HealthyThresholdCount 2 -UnhealthyThresholdCount 5 -Port 80 -Protocol 'HTTP' -TargetType instance -VpcId 'vpc-2cfd7000' -Name 'NewTargetGroup'
```
**Output:**
```
HealthCheckEnabled : True
HealthCheckIntervalSeconds : 30
HealthCheckPath : /index.html
HealthCheckPort : 80
HealthCheckProtocol : HTTP
HealthCheckTimeoutSeconds : 5
HealthyThresholdCount : 2
LoadBalancerArns : {}
Matcher : Amazon.ElasticLoadBalancingV2.Model.Matcher
Port : 80
Protocol : HTTP
TargetGroupArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/NewTargetGroup/534e484681d801bf
TargetGroupName : NewTargetGroup
TargetType : instance
UnhealthyThresholdCount : 5
VpcId : vpc-2cfd7000
```
+ For API details, see [CreateTargetGroup](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example creates new Target group with the provided parameters.**
```
New-ELB2TargetGroup -HealthCheckEnabled 1 -HealthCheckIntervalSeconds 30 -HealthCheckPath '/index.html' -HealthCheckPort 80 -HealthCheckTimeoutSecond 5 -HealthyThresholdCount 2 -UnhealthyThresholdCount 5 -Port 80 -Protocol 'HTTP' -TargetType instance -VpcId 'vpc-2cfd7000' -Name 'NewTargetGroup'
```
**Output:**
```
HealthCheckEnabled : True
HealthCheckIntervalSeconds : 30
HealthCheckPath : /index.html
HealthCheckPort : 80
HealthCheckProtocol : HTTP
HealthCheckTimeoutSeconds : 5
HealthyThresholdCount : 2
LoadBalancerArns : {}
Matcher : Amazon.ElasticLoadBalancingV2.Model.Matcher
Port : 80
Protocol : HTTP
TargetGroupArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/NewTargetGroup/534e484681d801bf
TargetGroupName : NewTargetGroup
TargetType : instance
UnhealthyThresholdCount : 5
VpcId : vpc-2cfd7000
```
+ For API details, see [CreateTargetGroup](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def create_target_group(
self, target_group_name: str, protocol: str, port: int, vpc_id: str
) -> Dict[str, Any]:
"""
Creates an Elastic Load Balancing target group. The target group specifies how
the load balancer forwards requests to instances in the group and how instance
health is checked.
To speed up this demo, the health check is configured with shortened times and
lower thresholds. In production, you might want to decrease the sensitivity of
your health checks to avoid unwanted failures.
:param target_group_name: The name of the target group to create.
:param protocol: The protocol to use to forward requests, such as 'HTTP'.
:param port: The port to use to forward requests, such as 80.
:param vpc_id: The ID of the VPC in which the load balancer exists.
:return: Data about the newly created target group.
"""
try:
response = self.elb_client.create_target_group(
Name=target_group_name,
Protocol=protocol,
Port=port,
HealthCheckPath="/healthcheck",
HealthCheckIntervalSeconds=10,
HealthCheckTimeoutSeconds=5,
HealthyThresholdCount=2,
UnhealthyThresholdCount=2,
VpcId=vpc_id,
)
target_group = response["TargetGroups"][0]
log.info(f"Created load balancing target group '{target_group_name}'.")
return target_group
except ClientError as err:
log.error(
f"Couldn't create load balancing target group '{target_group_name}'."
)
error_code = err.response["Error"]["Code"]
if error_code == "DuplicateTargetGroupName":
log.error(
f"Target group name {target_group_name} already exists. "
"Check if the target group already exists."
"Consider using a different name or deleting the existing target group if appropriate."
)
elif error_code == "TooManyTargetGroups":
log.error(
"Too many target groups exist in the account. "
"Consider deleting unused target groups to create space for new ones."
)
log.error(f"Full error:\n\t{err}")
```
+ For API details, see [CreateTargetGroup](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/CreateTargetGroup) in *AWS SDK for Python (Boto3) API Reference*.
------
# Use `DeleteListener` with a CLI
The following code examples show how to use `DeleteListener`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example:
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ CLI ]
**AWS CLI**
**To delete a listener**
The following `delete-listener` example deletes the specified listener.
```
aws elbv2 delete-listener \
--listener-arn arn:aws:elasticloadbalancing:ua-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2
```
+ For API details, see [DeleteListener](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/delete-listener.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example deletes the specified Listener.**
```
Remove-ELB2Listener -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Listener (DeleteListener)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
**Example 2: This example removes specified listener from the Load balancer.**
```
Remove-ELB2Listener -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Listener (DeleteListener)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteListener](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example deletes the specified Listener.**
```
Remove-ELB2Listener -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Listener (DeleteListener)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
**Example 2: This example removes specified listener from the Load balancer.**
```
Remove-ELB2Listener -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Listener (DeleteListener)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteListener](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DeleteLoadBalancer` with an AWS SDK or CLI
The following code examples show how to use `DeleteLoadBalancer`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService/ElasticLoadBalancerActions#code-examples).
```
///
/// Delete a load balancer by its specified name.
///
/// The name of the load balancer to delete.
/// Async task.
public async Task DeleteLoadBalancerByName(string name)
{
try
{
var describeLoadBalancerResponse =
await _amazonElasticLoadBalancingV2.DescribeLoadBalancersAsync(
new DescribeLoadBalancersRequest()
{
Names = new List() { name }
});
var lbArn = describeLoadBalancerResponse.LoadBalancers[0].LoadBalancerArn;
await _amazonElasticLoadBalancingV2.DeleteLoadBalancerAsync(
new DeleteLoadBalancerRequest()
{
LoadBalancerArn = lbArn
}
);
}
catch (LoadBalancerNotFoundException)
{
Console.WriteLine($"Load balancer {name} not found.");
}
}
```
+ For API details, see [DeleteLoadBalancer](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DeleteLoadBalancer) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**To delete a load balancer**
The following `delete-load-balancer` example deletes the specified load balancer.
```
aws elbv2 delete-load-balancer \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188
```
+ For API details, see [DeleteLoadBalancer](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/delete-load-balancer.html) in *AWS CLI Command Reference*.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
```
// Deletes a load balancer.
public void deleteLoadBalancer(String lbName) {
try {
// Use a waiter to delete the Load Balancer.
DescribeLoadBalancersResponse res = getLoadBalancerClient()
.describeLoadBalancers(describe -> describe.names(lbName));
ElasticLoadBalancingV2Waiter loadBalancerWaiter = getLoadBalancerClient().waiter();
DescribeLoadBalancersRequest request = DescribeLoadBalancersRequest.builder()
.loadBalancerArns(res.loadBalancers().get(0).loadBalancerArn())
.build();
getLoadBalancerClient().deleteLoadBalancer(
builder -> builder.loadBalancerArn(res.loadBalancers().get(0).loadBalancerArn()));
WaiterResponse waiterResponse = loadBalancerWaiter
.waitUntilLoadBalancersDeleted(request);
waiterResponse.matched().response().ifPresent(System.out::println);
} catch (ElasticLoadBalancingV2Exception e) {
System.err.println(e.awsErrorDetails().errorMessage());
}
System.out.println(lbName + " was deleted.");
}
```
+ For API details, see [DeleteLoadBalancer](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DeleteLoadBalancer) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-resilient-service#code-examples).
```
const client = new ElasticLoadBalancingV2Client({});
const loadBalancer = await findLoadBalancer(NAMES.loadBalancerName);
await client.send(
new DeleteLoadBalancerCommand({
LoadBalancerArn: loadBalancer.LoadBalancerArn,
}),
);
await retry({ intervalInMs: 1000, maxRetries: 60 }, async () => {
const lb = await findLoadBalancer(NAMES.loadBalancerName);
if (lb) {
throw new Error("Load balancer still exists.");
}
});
```
+ For API details, see [DeleteLoadBalancer](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DeleteLoadBalancerCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example deletes the specified Load balancer.**
```
Remove-ELB2LoadBalancer -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2LoadBalancer (DeleteLoadBalancer)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteLoadBalancer](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example deletes the specified Load balancer.**
```
Remove-ELB2LoadBalancer -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2LoadBalancer (DeleteLoadBalancer)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteLoadBalancer](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def delete_load_balancer(self, load_balancer_name) -> None:
"""
Deletes a load balancer.
:param load_balancer_name: The name of the load balancer to delete.
"""
try:
response = self.elb_client.describe_load_balancers(
Names=[load_balancer_name]
)
lb_arn = response["LoadBalancers"][0]["LoadBalancerArn"]
self.elb_client.delete_load_balancer(LoadBalancerArn=lb_arn)
log.info("Deleted load balancer %s.", load_balancer_name)
waiter = self.elb_client.get_waiter("load_balancers_deleted")
log.info("Waiting for load balancer to be deleted...")
waiter.wait(Names=[load_balancer_name])
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Couldn't delete load balancer '{load_balancer_name}'. Error code: {error_code}, Message: {err.response['Error']['Message']}"
)
if error_code == "LoadBalancerNotFoundException":
log.error(
f"The load balancer '{load_balancer_name}' does not exist. "
"Please check the name and try again."
)
log.error(f"Full error:\n\t{err}")
```
+ For API details, see [DeleteLoadBalancer](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DeleteLoadBalancer) in *AWS SDK for Python (Boto3) API Reference*.
------
# Use `DeleteRule` with a CLI
The following code examples show how to use `DeleteRule`.
------
#### [ CLI ]
**AWS CLI**
**To delete a rule**
The following `delete-rule` example deletes the specified rule.
```
aws elbv2 delete-rule \
--rule-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener-rule/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2/1291d13826f405c3
```
+ For API details, see [DeleteRule](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/delete-rule.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example removes the specified rule from the Listener**
```
Remove-ELB2Rule -RuleArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/3873f123b98f7618/4b25eb10a42e33ab'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Rule (DeleteRule)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/3873f123b98f7618/4b25eb10a42e33ab".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteRule](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example removes the specified rule from the Listener**
```
Remove-ELB2Rule -RuleArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/3873f123b98f7618/4b25eb10a42e33ab'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Rule (DeleteRule)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/3873f123b98f7618/4b25eb10a42e33ab".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteRule](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DeleteTargetGroup` with an AWS SDK or CLI
The following code examples show how to use `DeleteTargetGroup`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService/ElasticLoadBalancerActions#code-examples).
```
///
/// Delete a TargetGroup by its specified name.
///
/// Name of the group to delete.
/// Async task.
public async Task DeleteTargetGroupByName(string groupName)
{
var done = false;
while (!done)
{
try
{
var groupResponse =
await _amazonElasticLoadBalancingV2.DescribeTargetGroupsAsync(
new DescribeTargetGroupsRequest()
{
Names = new List() { groupName }
});
var targetArn = groupResponse.TargetGroups[0].TargetGroupArn;
await _amazonElasticLoadBalancingV2.DeleteTargetGroupAsync(
new DeleteTargetGroupRequest() { TargetGroupArn = targetArn });
Console.WriteLine($"Deleted load balancing target group {groupName}.");
done = true;
}
catch (TargetGroupNotFoundException)
{
Console.WriteLine(
$"Target group {groupName} not found, could not delete.");
done = true;
}
catch (ResourceInUseException)
{
Console.WriteLine("Target group not yet released, waiting...");
Thread.Sleep(10000);
}
}
}
```
+ For API details, see [DeleteTargetGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DeleteTargetGroup) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**To delete a target group**
The following `delete-target-group` example deletes the specified target group.
```
aws elbv2 delete-target-group \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
This command produces no output.
For more information, see [Delete a load balancer](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-delete.html) in the *Application Load Balancer Guide*.
+ For API details, see [DeleteTargetGroup](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/delete-target-group.html) in *AWS CLI Command Reference*.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
```
// Deletes the target group.
public void deleteTargetGroup(String targetGroupName) {
try {
DescribeTargetGroupsResponse res = getLoadBalancerClient()
.describeTargetGroups(describe -> describe.names(targetGroupName));
getLoadBalancerClient()
.deleteTargetGroup(builder -> builder.targetGroupArn(res.targetGroups().get(0).targetGroupArn()));
} catch (ElasticLoadBalancingV2Exception e) {
System.err.println(e.awsErrorDetails().errorMessage());
}
System.out.println(targetGroupName + " was deleted.");
}
```
+ For API details, see [DeleteTargetGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DeleteTargetGroup) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-resilient-service#code-examples).
```
const client = new ElasticLoadBalancingV2Client({});
try {
const { TargetGroups } = await client.send(
new DescribeTargetGroupsCommand({
Names: [NAMES.loadBalancerTargetGroupName],
}),
);
await retry({ intervalInMs: 1000, maxRetries: 30 }, () =>
client.send(
new DeleteTargetGroupCommand({
TargetGroupArn: TargetGroups[0].TargetGroupArn,
}),
),
);
} catch (e) {
state.deleteLoadBalancerTargetGroupError = e;
}
```
+ For API details, see [DeleteTargetGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DeleteTargetGroupCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example removes the specified Target Group.**
```
Remove-ELB2TargetGroup -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/testsssss/4e0b6076bc6483a7'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2TargetGroup (DeleteTargetGroup)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/testsssss/4e0b6076bc6483a7".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteTargetGroup](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example removes the specified Target Group.**
```
Remove-ELB2TargetGroup -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/testsssss/4e0b6076bc6483a7'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2TargetGroup (DeleteTargetGroup)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/testsssss/4e0b6076bc6483a7".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [DeleteTargetGroup](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def delete_target_group(self, target_group_name) -> None:
"""
Deletes the target group.
"""
try:
# Describe the target group to get its ARN
response = self.elb_client.describe_target_groups(Names=[target_group_name])
tg_arn = response["TargetGroups"][0]["TargetGroupArn"]
# Delete the target group
self.elb_client.delete_target_group(TargetGroupArn=tg_arn)
log.info("Deleted load balancing target group %s.", target_group_name)
# Use a custom waiter to wait until the target group is no longer available
self.wait_for_target_group_deletion(self.elb_client, tg_arn)
log.info("Target group %s successfully deleted.", target_group_name)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(f"Failed to delete target group '{target_group_name}'.")
if error_code == "TargetGroupNotFound":
log.error(
"Load balancer target group either already deleted or never existed. "
"Verify the name and check that the resource exists in the AWS Console."
)
elif error_code == "ResourceInUseException":
log.error(
"Target group still in use by another resource. "
"Ensure that the target group is no longer associated with any load balancers or resources.",
)
log.error(f"Full error:\n\t{err}")
def wait_for_target_group_deletion(
self, elb_client, target_group_arn, max_attempts=10, delay=30
):
for attempt in range(max_attempts):
try:
elb_client.describe_target_groups(TargetGroupArns=[target_group_arn])
print(
f"Attempt {attempt + 1}: Target group {target_group_arn} still exists."
)
except ClientError as e:
if e.response["Error"]["Code"] == "TargetGroupNotFound":
print(
f"Target group {target_group_arn} has been successfully deleted."
)
return
else:
raise
time.sleep(delay)
raise TimeoutError(
f"Target group {target_group_arn} was not deleted after {max_attempts * delay} seconds."
)
```
+ For API details, see [DeleteTargetGroup](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DeleteTargetGroup) in *AWS SDK for Python (Boto3) API Reference*.
------
# Use `DeregisterTargets` with a CLI
The following code examples show how to use `DeregisterTargets`.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To deregister a target from a target group**
The following `deregister-targets` example removes the specified instance from the specified target group.
```
aws elbv2 deregister-targets \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067 \
--targets Id=i-1234567890abcdef0
```
**Example 2: To deregister a target registered using port overrides**
The following `deregister-targets` example removes an instance from a target group that was registered using port overrides.
```
aws elbv2 deregister-targets \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-internal-targets/3bb63f11dfb0faf9 \
--targets Id=i-1234567890abcdef0,Port=80 Id=i-1234567890abcdef0,Port=766
```
+ For API details, see [DeregisterTargets](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/deregister-targets.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example deregisters instance 'i-0672a4c4cdeae3111' from the specified Target group.**
```
$targetDescription = New-Object Amazon.ElasticLoadBalancingV2.Model.TargetDescription
$targetDescription.Id = 'i-0672a4c4cdeae3111'
Unregister-ELB2Target -Target $targetDescription -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
+ For API details, see [DeregisterTargets](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example deregisters instance 'i-0672a4c4cdeae3111' from the specified Target group.**
```
$targetDescription = New-Object Amazon.ElasticLoadBalancingV2.Model.TargetDescription
$targetDescription.Id = 'i-0672a4c4cdeae3111'
Unregister-ELB2Target -Target $targetDescription -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
+ For API details, see [DeregisterTargets](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeAccountLimits` with a CLI
The following code examples show how to use `DescribeAccountLimits`.
------
#### [ CLI ]
**AWS CLI**
**To describe your Elastic Load Balancing limits**
The following `describe-account-limits` example displays the Elastic Load Balancing limits for your AWS account in the current Region.
```
aws elbv2 describe-account-limits
```
Output:
```
{
"Limits": [
{
"Name": "target-groups",
"Max": "3000"
},
{
"Name": "targets-per-application-load-balancer",
"Max": "1000"
},
{
"Name": "listeners-per-application-load-balancer",
"Max": "50"
},
{
"Name": "rules-per-application-load-balancer",
"Max": "100"
},
{
"Name": "network-load-balancers",
"Max": "50"
},
{
"Name": "targets-per-network-load-balancer",
"Max": "3000"
},
{
"Name": "targets-per-availability-zone-per-network-load-balancer",
"Max": "500"
},
{
"Name": "listeners-per-network-load-balancer",
"Max": "50"
},
{
"Name": "condition-values-per-alb-rule",
"Max": "5"
},
{
"Name": "condition-wildcards-per-alb-rule",
"Max": "5"
},
{
"Name": "target-groups-per-application-load-balancer",
"Max": "100"
},
{
"Name": "target-groups-per-action-on-application-load-balancer",
"Max": "5"
},
{
"Name": "target-groups-per-action-on-network-load-balancer",
"Max": "1"
},
{
"Name": "certificates-per-application-load-balancer",
"Max": "25"
},
{
"Name": "certificates-per-network-load-balancer",
"Max": "25"
},
{
"Name": "targets-per-target-group",
"Max": "1000"
},
{
"Name": "target-id-registrations-per-application-load-balancer",
"Max": "1000"
},
{
"Name": "network-load-balancer-enis-per-vpc",
"Max": "1200"
},
{
"Name": "application-load-balancers",
"Max": "50"
},
{
"Name": "gateway-load-balancers",
"Max": "100"
},
{
"Name": "gateway-load-balancers-per-vpc",
"Max": "100"
},
{
"Name": "geneve-target-groups",
"Max": "100"
},
{
"Name": "targets-per-availability-zone-per-gateway-load-balancer",
"Max": "300"
}
]
}
```
For more information, see [Quotas](https://docs.aws.amazon.com/general/latest/gr/elb.html#limits_elastic_load_balancer) in the *AWS General Reference*.
+ For API details, see [DescribeAccountLimits](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-account-limits.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This command lists ELB2 account limits for a given region.**
```
Get-ELB2AccountLimit
```
**Output:**
```
Max Name
--- ----
3000 target-groups
1000 targets-per-application-load-balancer
50 listeners-per-application-load-balancer
100 rules-per-application-load-balancer
50 network-load-balancers
3000 targets-per-network-load-balancer
500 targets-per-availability-zone-per-network-load-balancer
50 listeners-per-network-load-balancer
5 condition-values-per-alb-rule
5 condition-wildcards-per-alb-rule
100 target-groups-per-application-load-balancer
5 target-groups-per-action-on-application-load-balancer
1 target-groups-per-action-on-network-load-balancer
50 application-load-balancers
```
+ For API details, see [DescribeAccountLimits](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This command lists ELB2 account limits for a given region.**
```
Get-ELB2AccountLimit
```
**Output:**
```
Max Name
--- ----
3000 target-groups
1000 targets-per-application-load-balancer
50 listeners-per-application-load-balancer
100 rules-per-application-load-balancer
50 network-load-balancers
3000 targets-per-network-load-balancer
500 targets-per-availability-zone-per-network-load-balancer
50 listeners-per-network-load-balancer
5 condition-values-per-alb-rule
5 condition-wildcards-per-alb-rule
100 target-groups-per-application-load-balancer
5 target-groups-per-action-on-application-load-balancer
1 target-groups-per-action-on-network-load-balancer
50 application-load-balancers
```
+ For API details, see [DescribeAccountLimits](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeListenerCertificates` with a CLI
The following code examples show how to use `DescribeListenerCertificates`.
------
#### [ CLI ]
**AWS CLI**
**To describe the certificates for a secure listener**
This example describes the certificates for the specified secure listener.
Command:
```
aws elbv2 describe-listener-certificates --listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2
```
Output:
```
{
"Certificates": [
{
"CertificateArn": "arn:aws:acm:us-west-2:123456789012:certificate/5cc54884-f4a3-4072-80be-05b9ba72f705",
"IsDefault": false
},
{
"CertificateArn": "arn:aws:acm:us-west-2:123456789012:certificate/3dcb0a41-bd72-4774-9ad9-756919c40557",
"IsDefault": false
},
{
"CertificateArn": "arn:aws:acm:us-west-2:123456789012:certificate/fe59da96-6f58-4a22-8eed-6d0d50477e1d",
"IsDefault": true
}
]
}
```
+ For API details, see [DescribeListenerCertificates](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-listener-certificates.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This examples describes the certificate for the specified listener.**
```
Get-ELB2ListenerCertificate -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b'
```
**Output:**
```
CertificateArn IsDefault
-------------- ---------
arn:aws:acm:us-east-1:123456789012:certificate/5fc7c092-68bf-4862-969c-22fd48b6e17c True
```
+ For API details, see [DescribeListenerCertificates](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This examples describes the certificate for the specified listener.**
```
Get-ELB2ListenerCertificate -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b'
```
**Output:**
```
CertificateArn IsDefault
-------------- ---------
arn:aws:acm:us-east-1:123456789012:certificate/5fc7c092-68bf-4862-969c-22fd48b6e17c True
```
+ For API details, see [DescribeListenerCertificates](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeListeners` with a CLI
The following code examples show how to use `DescribeListeners`.
------
#### [ CLI ]
**AWS CLI**
**To describe a listener**
This example describes the specified listener.
Command:
```
aws elbv2 describe-listeners --listener-arns arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2
```
Output:
```
{
"Listeners": [
{
"Port": 80,
"Protocol": "HTTP",
"DefaultActions": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
"Type": "forward"
}
],
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
"ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2"
}
]
}
```
**To describe the listeners for a load balancer**
This example describe the listeners for the specified load balancer.
Command:
```
aws elbv2 describe-listeners --load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188
```
Output:
```
{
"Listeners": [
{
"Port": 443,
"Protocol": "HTTPS",
"DefaultActions": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
"Type": "forward"
}
],
"SslPolicy": "ELBSecurityPolicy-2015-05",
"Certificates": [
{
"CertificateArn": "arn:aws:iam::123456789012:server-certificate/my-server-cert"
}
],
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
"ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/0467ef3c8400ae65"
},
{
"Port": 80,
"Protocol": "HTTP",
"DefaultActions": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
"Type": "forward"
}
],
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
"ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2"
}
]
}
```
+ For API details, see [DescribeListeners](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-listeners.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This examples describes listeners of the specified ALB/NLB.**
```
Get-ELB2Listener -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f'
```
**Output:**
```
Certificates : {}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/1dac07c21187d41e
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f
Port : 80
Protocol : HTTP
SslPolicy :
Certificates : {Amazon.ElasticLoadBalancingV2.Model.Certificate}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f
Port : 443
Protocol : HTTPS
SslPolicy : ELBSecurityPolicy-2016-08
```
+ For API details, see [DescribeListeners](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This examples describes listeners of the specified ALB/NLB.**
```
Get-ELB2Listener -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f'
```
**Output:**
```
Certificates : {}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/1dac07c21187d41e
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f
Port : 80
Protocol : HTTP
SslPolicy :
Certificates : {Amazon.ElasticLoadBalancingV2.Model.Certificate}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f
Port : 443
Protocol : HTTPS
SslPolicy : ELBSecurityPolicy-2016-08
```
+ For API details, see [DescribeListeners](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeLoadBalancerAttributes` with a CLI
The following code examples show how to use `DescribeLoadBalancerAttributes`.
------
#### [ CLI ]
**AWS CLI**
**To describe load balancer attributes**
The following `describe-load-balancer-attributes` example displays the attributes of the specified load balancer.
```
aws elbv2 describe-load-balancer-attributes \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188
```
The following example output show the attributes for an Application Load Balancer.
```
{
"Attributes": [
{
"Value": "false",
"Key": "access_logs.s3.enabled"
},
{
"Value": "",
"Key": "access_logs.s3.bucket"
},
{
"Value": "",
"Key": "access_logs.s3.prefix"
},
{
"Value": "60",
"Key": "idle_timeout.timeout_seconds"
},
{
"Value": "false",
"Key": "deletion_protection.enabled"
},
{
"Value": "true",
"Key": "routing.http2.enabled"
}
]
}
```
The following example output includes the attributes for a Network Load Balancer.
```
{
"Attributes": [
{
"Value": "false",
"Key": "access_logs.s3.enabled"
},
{
"Value": "",
"Key": "access_logs.s3.bucket"
},
{
"Value": "",
"Key": "access_logs.s3.prefix"
},
{
"Value": "false",
"Key": "deletion_protection.enabled"
},
{
"Value": "false",
"Key": "load_balancing.cross_zone.enabled"
}
]
}
```
+ For API details, see [DescribeLoadBalancerAttributes](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-load-balancer-attributes.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This command describes the attributes of given Load balancer.**
```
Get-ELB2LoadBalancerAttribute -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/net/test-elb/238d34ad8d94bc2e'
```
**Output:**
```
Key Value
--- -----
access_logs.s3.enabled false
load_balancing.cross_zone.enabled true
access_logs.s3.prefix
deletion_protection.enabled false
access_logs.s3.bucket
```
+ For API details, see [DescribeLoadBalancerAttributes](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This command describes the attributes of given Load balancer.**
```
Get-ELB2LoadBalancerAttribute -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/net/test-elb/238d34ad8d94bc2e'
```
**Output:**
```
Key Value
--- -----
access_logs.s3.enabled false
load_balancing.cross_zone.enabled true
access_logs.s3.prefix
deletion_protection.enabled false
access_logs.s3.bucket
```
+ For API details, see [DescribeLoadBalancerAttributes](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeLoadBalancers` with an AWS SDK or CLI
The following code examples show how to use `DescribeLoadBalancers`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService/ElasticLoadBalancerActions#code-examples).
```
///
/// Get the HTTP Endpoint of a load balancer by its name.
///
/// The name of the load balancer.
/// The HTTP endpoint.
public async Task GetEndpointForLoadBalancerByName(string loadBalancerName)
{
if (_endpoint == null)
{
var endpointResponse =
await _amazonElasticLoadBalancingV2.DescribeLoadBalancersAsync(
new DescribeLoadBalancersRequest()
{
Names = new List() { loadBalancerName }
});
_endpoint = endpointResponse.LoadBalancers[0].DNSName;
}
return _endpoint;
}
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**To describe a load balancer**
This example describes the specified load balancer.
Command:
```
aws elbv2 describe-load-balancers --load-balancer-arns arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188
```
Output:
```
{
"LoadBalancers": [
{
"Type": "application",
"Scheme": "internet-facing",
"IpAddressType": "ipv4",
"VpcId": "vpc-3ac0fb5f",
"AvailabilityZones": [
{
"ZoneName": "us-west-2a",
"SubnetId": "subnet-8360a9e7"
},
{
"ZoneName": "us-west-2b",
"SubnetId": "subnet-b7d581c0"
}
],
"CreatedTime": "2016-03-25T21:26:12.920Z",
"CanonicalHostedZoneId": "Z2P70J7EXAMPLE",
"DNSName": "my-load-balancer-424835706.us-west-2.elb.amazonaws.com",
"SecurityGroups": [
"sg-5943793c"
],
"LoadBalancerName": "my-load-balancer",
"State": {
"Code": "active"
},
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188"
}
]
}
```
**To describe all load balancers**
This example describes all of your load balancers.
Command:
```
aws elbv2 describe-load-balancers
```
+ For API details, see [DescribeLoadBalancers](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-load-balancers.html) in *AWS CLI Command Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/elastic-load-balancing-v2#code-examples).
```
import {
ElasticLoadBalancingV2Client,
DescribeLoadBalancersCommand,
} from "@aws-sdk/client-elastic-load-balancing-v2";
export async function main() {
const client = new ElasticLoadBalancingV2Client({});
const { LoadBalancers } = await client.send(
new DescribeLoadBalancersCommand({}),
);
const loadBalancersList = LoadBalancers.map(
(lb) => `• ${lb.LoadBalancerName}: ${lb.DNSName}`,
).join("\n");
console.log(
"Hello, Elastic Load Balancing! Let's list some of your load balancers:\n",
loadBalancersList,
);
}
// Call function if run directly
import { fileURLToPath } from "node:url";
if (process.argv[1] === fileURLToPath(import.meta.url)) {
main();
}
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DescribeLoadBalancersCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This sample displays all the load balancers for the given region.**
```
Get-ELB2LoadBalancer
```
**Output:**
```
AvailabilityZones : {us-east-1c}
CanonicalHostedZoneId : Z26RNL4JYFTOTI
CreatedTime : 6/22/18 11:21:50 AM
DNSName : test-elb1234567890-238d34ad8d94bc2e.elb.us-east-1.amazonaws.com
IpAddressType : ipv4
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/net/test-elb1234567890/238d34ad8d94bc2e
LoadBalancerName : test-elb1234567890
Scheme : internet-facing
SecurityGroups : {}
State : Amazon.ElasticLoadBalancingV2.Model.LoadBalancerState
Type : network
VpcId : vpc-2cf00000
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This sample displays all the load balancers for the given region.**
```
Get-ELB2LoadBalancer
```
**Output:**
```
AvailabilityZones : {us-east-1c}
CanonicalHostedZoneId : Z26RNL4JYFTOTI
CreatedTime : 6/22/18 11:21:50 AM
DNSName : test-elb1234567890-238d34ad8d94bc2e.elb.us-east-1.amazonaws.com
IpAddressType : ipv4
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/net/test-elb1234567890/238d34ad8d94bc2e
LoadBalancerName : test-elb1234567890
Scheme : internet-facing
SecurityGroups : {}
State : Amazon.ElasticLoadBalancingV2.Model.LoadBalancerState
Type : network
VpcId : vpc-2cf00000
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def get_endpoint(self, load_balancer_name) -> str:
"""
Gets the HTTP endpoint of the load balancer.
:return: The endpoint.
"""
try:
response = self.elb_client.describe_load_balancers(
Names=[load_balancer_name]
)
return response["LoadBalancers"][0]["DNSName"]
except ClientError as err:
log.error(
f"Couldn't get the endpoint for load balancer {load_balancer_name}"
)
error_code = err.response["Error"]["Code"]
if error_code == "LoadBalancerNotFoundException":
log.error(
"Verify load balancer name and ensure it exists in the AWS console."
)
log.error(f"Full error:\n\t{err}")
```
+ For API details, see [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers) in *AWS SDK for Python (Boto3) API Reference*.
------
# Use `DescribeRules` with a CLI
The following code examples show how to use `DescribeRules`.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To describe a rule**
The following `describe-rules` example displays details for the specified rule.
```
aws elbv2 describe-rules \
--rule-arns arn:aws:elasticloadbalancing:us-west-2:123456789012:listener-rule/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2/9683b2d02a6cabee
```
**Example 2: To describe the rules for a listener**
The following `describe-rules` example displays details for the rules for the specified listener. The output includes the default rule and any other rules that you've added.
```
aws elbv2 describe-rules \
--listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2
```
+ For API details, see [DescribeRules](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-rules.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example describes the listener rules for the specified Listener ARN.**
```
Get-ELB2Rule -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b'
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 1
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b/2286fff5055e0f79
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 2
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b/14e7b036567623ba
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {}
IsDefault : True
Priority : default
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b/853948cf3aa9b2bf
```
+ For API details, see [DescribeRules](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example describes the listener rules for the specified Listener ARN.**
```
Get-ELB2Rule -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b'
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 1
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b/2286fff5055e0f79
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 2
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b/14e7b036567623ba
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {}
IsDefault : True
Priority : default
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/66e10e3aaf5b6d9b/853948cf3aa9b2bf
```
+ For API details, see [DescribeRules](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeSslPolicies` with a CLI
The following code examples show how to use `DescribeSslPolicies`.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To list the policies used for SSL negotiation by load balancer type**
The following `describe-ssl-policies` example displays the names of the polices that you can use for SSL negotiation with an Application Load Balancer. The example uses the `--query` parameter to display only the names of the policies.
```
aws elbv2 describe-ssl-policies \
--load-balancer-type application \
--query SslPolicies[*].Name
```
Output:
```
[
"ELBSecurityPolicy-2016-08",
"ELBSecurityPolicy-TLS13-1-2-2021-06",
"ELBSecurityPolicy-TLS13-1-2-Res-2021-06",
"ELBSecurityPolicy-TLS13-1-2-Ext1-2021-06",
"ELBSecurityPolicy-TLS13-1-2-Ext2-2021-06",
"ELBSecurityPolicy-TLS13-1-1-2021-06",
"ELBSecurityPolicy-TLS13-1-0-2021-06",
"ELBSecurityPolicy-TLS13-1-3-2021-06",
"ELBSecurityPolicy-TLS-1-2-2017-01",
"ELBSecurityPolicy-TLS-1-1-2017-01",
"ELBSecurityPolicy-TLS-1-2-Ext-2018-06",
"ELBSecurityPolicy-FS-2018-06",
"ELBSecurityPolicy-2015-05",
"ELBSecurityPolicy-TLS-1-0-2015-04",
"ELBSecurityPolicy-FS-1-2-Res-2019-08",
"ELBSecurityPolicy-FS-1-1-2019-08",
"ELBSecurityPolicy-FS-1-2-2019-08",
"ELBSecurityPolicy-FS-1-2-Res-2020-10"
]
```
**Example 2: To list the policies that support a specific protocol**
The following `describe-ssl-policies` example displays the names of the polices that support the TLS 1.3 protocol. The example uses the `--query` parameter to display only the names of the policies.
```
aws elbv2 describe-ssl-policies \
--load-balancer-type application \
--query SslPolicies[?contains(SslProtocols,'TLSv1.3')].Name
```
Output:
```
[
"ELBSecurityPolicy-TLS13-1-2-2021-06",
"ELBSecurityPolicy-TLS13-1-2-Res-2021-06",
"ELBSecurityPolicy-TLS13-1-2-Ext1-2021-06",
"ELBSecurityPolicy-TLS13-1-2-Ext2-2021-06",
"ELBSecurityPolicy-TLS13-1-1-2021-06",
"ELBSecurityPolicy-TLS13-1-0-2021-06",
"ELBSecurityPolicy-TLS13-1-3-2021-06"
]
```
**Example 3: To display the ciphers for a policy**
The following `describe-ssl-policies` example displays the names of the ciphers for the specified policy. The example uses the `--query` parameter to display only the cipher names. The first cipher in the list has priority 1, and the remaining ciphers are in priority order.
```
aws elbv2 describe-ssl-policies \
--names ELBSecurityPolicy-TLS13-1-2-2021-06 \
--query SslPolicies[*].Ciphers[*].Name
```
Output:
```
[
"TLS_AES_128_GCM_SHA256",
"TLS_AES_256_GCM_SHA384",
"TLS_CHACHA20_POLY1305_SHA256",
"ECDHE-ECDSA-AES128-GCM-SHA256",
"ECDHE-RSA-AES128-GCM-SHA256",
"ECDHE-ECDSA-AES128-SHA256",
"ECDHE-RSA-AES128-SHA256",
"ECDHE-ECDSA-AES256-GCM-SHA384",
"ECDHE-RSA-AES256-GCM-SHA384",
"ECDHE-ECDSA-AES256-SHA384",
"ECDHE-RSA-AES256-SHA384"
]
```
For more information, see [Security policies](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/create-https-listener.html#describe-ssl-policies) in the *User Guide for Application Load Balancers*.
+ For API details, see [DescribeSslPolicies](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-ssl-policies.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This examples lists all available listener policies for ElasticLoadBalancingV2.**
```
Get-ELB2SSLPolicy
```
**Output:**
```
Ciphers Name SslProtocols
------- ---- ------------
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-2016-08 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-2-2017-01 {TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-1-2017-01 {TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-2-Ext-2018-06 {TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-2018-06 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-2015-05 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-0-2015-04 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-1-2-Res-2019-08 {TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-1-1-2019-08 {TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-1-2-2019-08 {TLSv1.2}
```
+ For API details, see [DescribeSslPolicies](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This examples lists all available listener policies for ElasticLoadBalancingV2.**
```
Get-ELB2SSLPolicy
```
**Output:**
```
Ciphers Name SslProtocols
------- ---- ------------
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-2016-08 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-2-2017-01 {TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-1-2017-01 {TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-2-Ext-2018-06 {TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-2018-06 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-2015-05 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-TLS-1-0-2015-04 {TLSv1, TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-1-2-Res-2019-08 {TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-1-1-2019-08 {TLSv1.1, TLSv1.2}
{ECDHE-ECDSA-AES128-GCM-SHA256, ECDHE-RSA-AES128-GCM-SHA256, ECDHE-ECDSA-AES128-SHA256, ECDHE-RSA-AES128-SHA256} ELBSecurityPolicy-FS-1-2-2019-08 {TLSv1.2}
```
+ For API details, see [DescribeSslPolicies](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeTags` with a CLI
The following code examples show how to use `DescribeTags`.
------
#### [ CLI ]
**AWS CLI**
**To describe the tags assigned to a load balancer**
This example describes the tags assigned to the specified load balancer.
Command:
```
aws elbv2 describe-tags --resource-arns arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188
```
Output:
```
{
"TagDescriptions": [
{
"ResourceArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
"Tags": [
{
"Value": "lima",
"Key": "project"
},
{
"Value": "digital-media",
"Key": "department"
}
]
}
]
}
```
+ For API details, see [DescribeTags](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-tags.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example lists the Tags for the specified resource.**
```
Get-ELB2Tag -ResourceArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f'
```
**Output:**
```
ResourceArn Tags
----------- ----
arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f {stage, internalName, version}
```
+ For API details, see [DescribeTags](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example lists the Tags for the specified resource.**
```
Get-ELB2Tag -ResourceArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f'
```
**Output:**
```
ResourceArn Tags
----------- ----
arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f {stage, internalName, version}
```
+ For API details, see [DescribeTags](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeTargetGroupAttributes` with a CLI
The following code examples show how to use `DescribeTargetGroupAttributes`.
------
#### [ CLI ]
**AWS CLI**
**To describe target group attributes**
The following `describe-target-group-attributes` example displays the attributes of the specified target group.
```
aws elbv2 describe-target-group-attributes \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
The output includes the attributes if the protocol is HTTP or HTTPS and the target type is `instance` or `ip`.
```
{
"Attributes": [
{
"Value": "false",
"Key": "stickiness.enabled"
},
{
"Value": "300",
"Key": "deregistration_delay.timeout_seconds"
},
{
"Value": "lb_cookie",
"Key": "stickiness.type"
},
{
"Value": "86400",
"Key": "stickiness.lb_cookie.duration_seconds"
},
{
"Value": "0",
"Key": "slow_start.duration_seconds"
}
]
}
```
The following output includes the attributes if the protocol is HTTP or HTTPS and the target type is `lambda`.
```
{
"Attributes": [
{
"Value": "false",
"Key": "lambda.multi_value_headers.enabled"
}
]
}
```
The following output includes the attributes if the protocol is TCP, TLS, UDP, or TCP\$1UDP.
```
{
"Attributes": [
{
"Value": "false",
"Key": "proxy_protocol_v2.enabled"
},
{
"Value": "300",
"Key": "deregistration_delay.timeout_seconds"
}
]
}
```
+ For API details, see [DescribeTargetGroupAttributes](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-target-group-attributes.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example describes the attributes of the specified Target Group.**
```
Get-ELB2TargetGroupAttribute -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
**Output:**
```
Key Value
--- -----
stickiness.enabled false
deregistration_delay.timeout_seconds 300
stickiness.type lb_cookie
stickiness.lb_cookie.duration_seconds 86400
slow_start.duration_seconds 0
load_balancing.algorithm.type round_robin
```
+ For API details, see [DescribeTargetGroupAttributes](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example describes the attributes of the specified Target Group.**
```
Get-ELB2TargetGroupAttribute -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
**Output:**
```
Key Value
--- -----
stickiness.enabled false
deregistration_delay.timeout_seconds 300
stickiness.type lb_cookie
stickiness.lb_cookie.duration_seconds 86400
slow_start.duration_seconds 0
load_balancing.algorithm.type round_robin
```
+ For API details, see [DescribeTargetGroupAttributes](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeTargetGroups` with an AWS SDK or CLI
The following code examples show how to use `DescribeTargetGroups`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
------
#### [ CLI ]
**AWS CLI**
**Example 1: To describe a target group**
The following `describe-target-groups` example displays details for the specified target group.
```
aws elbv2 describe-target-groups \
--target-group-arns arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
Output:
```
{
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
"TargetGroupName": "my-targets",
"Protocol": "HTTP",
"Port": 80,
"VpcId": "vpc-3ac0fb5f",
"HealthCheckProtocol": "HTTP",
"HealthCheckPort": "traffic-port",
"HealthCheckEnabled": true,
"HealthCheckIntervalSeconds": 30,
"HealthCheckTimeoutSeconds": 5,
"HealthyThresholdCount": 5,
"UnhealthyThresholdCount": 2,
"HealthCheckPath": "/",
"Matcher": {
"HttpCode": "200"
},
"LoadBalancerArns": [
"arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188"
],
"TargetType": "instance",
"ProtocolVersion": "HTTP1",
"IpAddressType": "ipv4"
}
]
}
```
**Example 2: To describe all target groups for a load balancer**
The following `describe-target-groups` example displays details for all target groups for the specified load balancer. The example uses the `--query` parameter to display only the target group names.
```
aws elbv2 describe-target-groups \
--load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 \
--query TargetGroups[*].TargetGroupName
```
Output:
```
[
"my-instance-targets",
"my-ip-targets",
"my-lambda-target"
]
```
For more information, see [Target groups](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-target-groups.html) in the *Application Load Balancers Guide*.
+ For API details, see [DescribeTargetGroups](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-target-groups.html) in *AWS CLI Command Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/elastic-load-balancing-v2#code-examples).
```
const client = new ElasticLoadBalancingV2Client({});
const { TargetGroups } = await client.send(
new DescribeTargetGroupsCommand({
Names: [NAMES.loadBalancerTargetGroupName],
}),
);
```
+ For API details, see [DescribeTargetGroups](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DescribeTargetGroupsCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example describes the specified Target Group.**
```
Get-ELB2TargetGroup -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
**Output:**
```
HealthCheckEnabled : True
HealthCheckIntervalSeconds : 30
HealthCheckPath : /
HealthCheckPort : traffic-port
HealthCheckProtocol : HTTP
HealthCheckTimeoutSeconds : 5
HealthyThresholdCount : 5
LoadBalancerArns : {arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f}
Matcher : Amazon.ElasticLoadBalancingV2.Model.Matcher
Port : 80
Protocol : HTTP
TargetGroupArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970
TargetGroupName : test-tg
TargetType : instance
UnhealthyThresholdCount : 2
VpcId : vpc-2cfd7000
```
+ For API details, see [DescribeTargetGroups](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example describes the specified Target Group.**
```
Get-ELB2TargetGroup -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
**Output:**
```
HealthCheckEnabled : True
HealthCheckIntervalSeconds : 30
HealthCheckPath : /
HealthCheckPort : traffic-port
HealthCheckProtocol : HTTP
HealthCheckTimeoutSeconds : 5
HealthyThresholdCount : 5
LoadBalancerArns : {arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f}
Matcher : Amazon.ElasticLoadBalancingV2.Model.Matcher
Port : 80
Protocol : HTTP
TargetGroupArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970
TargetGroupName : test-tg
TargetType : instance
UnhealthyThresholdCount : 2
VpcId : vpc-2cfd7000
```
+ For API details, see [DescribeTargetGroups](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `DescribeTargetHealth` with an AWS SDK or CLI
The following code examples show how to use `DescribeTargetHealth`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService/ElasticLoadBalancerActions#code-examples).
```
///
/// Get the target health for a group by name.
///
/// The name of the group.
/// The collection of health descriptions.
public async Task> CheckTargetHealthForGroup(string groupName)
{
List result = null!;
try
{
var groupResponse =
await _amazonElasticLoadBalancingV2.DescribeTargetGroupsAsync(
new DescribeTargetGroupsRequest()
{
Names = new List() { groupName }
});
var healthResponse =
await _amazonElasticLoadBalancingV2.DescribeTargetHealthAsync(
new DescribeTargetHealthRequest()
{
TargetGroupArn = groupResponse.TargetGroups[0].TargetGroupArn
});
;
result = healthResponse.TargetHealthDescriptions;
}
catch (TargetGroupNotFoundException)
{
Console.WriteLine($"Target group {groupName} not found.");
}
return result;
}
```
+ For API details, see [DescribeTargetHealth](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DescribeTargetHealth) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To describe the health of the targets for a target group**
The following `describe-target-health` example displays health details for the targets of the specified target group. These targets are healthy.
```
aws elbv2 describe-target-health \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
Output:
```
{
"TargetHealthDescriptions": [
{
"HealthCheckPort": "80",
"Target": {
"Id": "i-ceddcd4d",
"Port": 80
},
"TargetHealth": {
"State": "healthy"
}
},
{
"HealthCheckPort": "80",
"Target": {
"Id": "i-0f76fade",
"Port": 80
},
"TargetHealth": {
"State": "healthy"
}
}
]
}
```
**Example 2: To describe the health of a target**
The following `describe-target-health` example displays health details for the specified target. This target is healthy.
```
aws elbv2 describe-target-health \
--targets Id=i-0f76fade,Port=80 \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067
```
Output:
```
{
"TargetHealthDescriptions": [
{
"HealthCheckPort": "80",
"Target": {
"Id": "i-0f76fade",
"Port": 80
},
"TargetHealth": {
"State": "healthy"
}
}
]
}
```
The following example output is for a target whose target group is not specified in an action for a listener. This target can't receive traffic from the load balancer.
```
{
"TargetHealthDescriptions": [
{
"HealthCheckPort": "80",
"Target": {
"Id": "i-0f76fade",
"Port": 80
},
"TargetHealth": {
"State": "unused",
"Reason": "Target.NotInUse",
"Description": "Target group is not configured to receive traffic from the load balancer"
}
}
]
}
```
The following example output is for a target whose target group was just specified in an action for a listener. The target is still being registered.
```
{
"TargetHealthDescriptions": [
{
"HealthCheckPort": "80",
"Target": {
"Id": "i-0f76fade",
"Port": 80
},
"TargetHealth": {
"State": "initial",
"Reason": "Elb.RegistrationInProgress",
"Description": "Target registration is in progress"
}
}
]
}
```
The following example output is for an unhealthy target.
```
{
"TargetHealthDescriptions": [
{
"HealthCheckPort": "80",
"Target": {
"Id": "i-0f76fade",
"Port": 80
},
"TargetHealth": {
"State": "unhealthy",
"Reason": "Target.Timeout",
"Description": "Connection to target timed out"
}
}
]
}
```
The following example output is for a target that is a Lambda function and health checks are disabled.
```
{
"TargetHealthDescriptions": [
{
"Target": {
"Id": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
"AvailabilityZone": "all",
},
"TargetHealth": {
"State": "unavailable",
"Reason": "Target.HealthCheckDisabled",
"Description": "Health checks are not enabled for this target"
}
}
]
}
```
+ For API details, see [DescribeTargetHealth](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/describe-target-health.html) in *AWS CLI Command Reference*.
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
```
// Checks the health of the instances in the target group.
public List checkTargetHealth(String targetGroupName) {
DescribeTargetGroupsRequest targetGroupsRequest = DescribeTargetGroupsRequest.builder()
.names(targetGroupName)
.build();
DescribeTargetGroupsResponse tgResponse = getLoadBalancerClient().describeTargetGroups(targetGroupsRequest);
DescribeTargetHealthRequest healthRequest = DescribeTargetHealthRequest.builder()
.targetGroupArn(tgResponse.targetGroups().get(0).targetGroupArn())
.build();
DescribeTargetHealthResponse healthResponse = getLoadBalancerClient().describeTargetHealth(healthRequest);
return healthResponse.targetHealthDescriptions();
}
```
+ For API details, see [DescribeTargetHealth](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DescribeTargetHealth) in *AWS SDK for Java 2.x API Reference*.
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-resilient-service#code-examples).
```
const { TargetHealthDescriptions } = await client.send(
new DescribeTargetHealthCommand({
TargetGroupArn: TargetGroups[0].TargetGroupArn,
}),
);
```
+ For API details, see [DescribeTargetHealth](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DescribeTargetHealthCommand) in *AWS SDK for JavaScript API Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example returns the health status of the Targets present in the specified Target Group.**
```
Get-ELB2TargetHealth -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
**Output:**
```
HealthCheckPort Target TargetHealth
--------------- ------ ------------
80 Amazon.ElasticLoadBalancingV2.Model.TargetDescription Amazon.ElasticLoadBalancingV2.Model.TargetHealth
```
+ For API details, see [DescribeTargetHealth](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example returns the health status of the Targets present in the specified Target Group.**
```
Get-ELB2TargetHealth -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970'
```
**Output:**
```
HealthCheckPort Target TargetHealth
--------------- ------ ------------
80 Amazon.ElasticLoadBalancingV2.Model.TargetDescription Amazon.ElasticLoadBalancingV2.Model.TargetHealth
```
+ For API details, see [DescribeTargetHealth](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/elastic-load-balancing#code-examples).
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def check_target_health(self, target_group_name: str) -> List[Dict[str, Any]]:
"""
Checks the health of the instances in the target group.
:return: The health status of the target group.
"""
try:
tg_response = self.elb_client.describe_target_groups(
Names=[target_group_name]
)
health_response = self.elb_client.describe_target_health(
TargetGroupArn=tg_response["TargetGroups"][0]["TargetGroupArn"]
)
except ClientError as err:
log.error(f"Couldn't check health of {target_group_name} target(s).")
error_code = err.response["Error"]["Code"]
if error_code == "LoadBalancerNotFoundException":
log.error(
"Load balancer associated with the target group was not found. "
"Ensure the load balancer exists, is in the correct AWS region, and "
"that you have the necessary permissions to access it.",
)
elif error_code == "TargetGroupNotFoundException":
log.error(
"Target group was not found. "
"Verify the target group name, check that it exists in the correct region, "
"and ensure it has not been deleted or created in a different account.",
)
log.error(f"Full error:\n\t{err}")
else:
return health_response["TargetHealthDescriptions"]
```
+ For API details, see [DescribeTargetHealth](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DescribeTargetHealth) in *AWS SDK for Python (Boto3) API Reference*.
------
# Use `ModifyListener` with a CLI
The following code examples show how to use `ModifyListener`.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To change the default action to a forward action**
The following `modify-listener` example changes the default action to a `forward` action for the specified listener.
```
aws elbv2 modify-listener \
--listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 \
--default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-new-targets/2453ed029918f21f
```
Output:
```
{
"Listeners": [
{
"ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2",
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
"Protocol": "HTTP",
"Port": 80,
"DefaultActions": [
{
"Type": "forward",
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-new-targets/2453ed029918f21f"
}
]
}
]
}
```
**Example 2: To change the default action to a redirect action**
The following `modify-listener` example changes the default action to a `redirect` action for the specified listener.
```
aws elbv2 modify-listener \
--listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 \
--default-actions Type=redirect, RedirectConfig='{Protocol=HTTPS,StatusCode=HTTP_302}'
```
Output:
```
{
"Listeners": [
{
"ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2",
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
"Protocol": "HTTP",
"Port": 80,
"DefaultActions": [
{
"Type": "redirect",
"RedirectConfig": {
"Protocol": "HTTPS",
"Port": "#{port}",
"Host": "#{host}",
"Path": "/#{path}",
"Query": "#{query}",
"StatusCode": "HTTP_302",
}
}
]
}
]
}
```
**Example 3: To change the server certificate**
The following `modify-listener` example changes the server certificate for the specified HTTPS listener.
```
aws elbv2 modify-listener \
--listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/0467ef3c8400ae65 \
--certificates CertificateArn=arn:aws:iam::123456789012:server-certificate/my-new-server-cert
```
Output:
```
{
"Listeners": [
{
"ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/0467ef3c8400ae65",
"LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
"Protocol": "HTTPS",
"Port": 443,
"DefaultActions": [
{
"Type": "forward",
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067"
}
],
"SslPolicy": "ELBSecurityPolicy-2015-05",
"Certificates": [
{
"CertificateArn": "arn:aws:iam::123456789012:server-certificate/my-new-server-cert"
}
],
}
]
}
```
For more information, see [Listener rules](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-listeners.html#listener-rules) in the *Application Load Balancers User Guide*.
+ For API details, see [ModifyListener](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/modify-listener.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example modifes the specified listeners default action to fixed-response.**
```
$newDefaultAction = [Amazon.ElasticLoadBalancingV2.Model.Action]@{
"FixedResponseConfig" = @{
"ContentType" = "text/plain"
"MessageBody" = "Hello World"
"StatusCode" = "200"
}
"Type" = [Amazon.ElasticLoadBalancingV2.ActionTypeEnum]::FixedResponse
}
Edit-ELB2Listener -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/d19f2f14974db685' -Port 8080 -DefaultAction $newDefaultAction
```
**Output:**
```
Certificates : {}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/d19f2f14974db685
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/testALB/3e2f03b558e19676
Port : 8080
Protocol : HTTP
SslPolicy :
```
+ For API details, see [ModifyListener](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example modifes the specified listeners default action to fixed-response.**
```
$newDefaultAction = [Amazon.ElasticLoadBalancingV2.Model.Action]@{
"FixedResponseConfig" = @{
"ContentType" = "text/plain"
"MessageBody" = "Hello World"
"StatusCode" = "200"
}
"Type" = [Amazon.ElasticLoadBalancingV2.ActionTypeEnum]::FixedResponse
}
Edit-ELB2Listener -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/d19f2f14974db685' -Port 8080 -DefaultAction $newDefaultAction
```
**Output:**
```
Certificates : {}
DefaultActions : {Amazon.ElasticLoadBalancingV2.Model.Action}
ListenerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/testALB/3e2f03b558e19676/d19f2f14974db685
LoadBalancerArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/testALB/3e2f03b558e19676
Port : 8080
Protocol : HTTP
SslPolicy :
```
+ For API details, see [ModifyListener](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `ModifyLoadBalancerAttributes` with a CLI
The following code examples show how to use `ModifyLoadBalancerAttributes`.
------
#### [ CLI ]
**AWS CLI**
**To enable deletion protection**
This example enables deletion protection for the specified load balancer.
Command:
```
aws elbv2 modify-load-balancer-attributes --load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 --attributes Key=deletion_protection.enabled,Value=true
```
Output:
```
{
"Attributes": [
{
"Value": "true",
"Key": "deletion_protection.enabled"
},
{
"Value": "false",
"Key": "access_logs.s3.enabled"
},
{
"Value": "60",
"Key": "idle_timeout.timeout_seconds"
},
{
"Value": "",
"Key": "access_logs.s3.prefix"
},
{
"Value": "",
"Key": "access_logs.s3.bucket"
}
]
}
```
**To change the idle timeout**
This example changes the idle timeout value for the specified load balancer.
Command:
```
aws elbv2 modify-load-balancer-attributes --load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 --attributes Key=idle_timeout.timeout_seconds,Value=30
```
Output:
```
{
"Attributes": [
{
"Value": "30",
"Key": "idle_timeout.timeout_seconds"
},
{
"Value": "false",
"Key": "access_logs.s3.enabled"
},
{
"Value": "",
"Key": "access_logs.s3.prefix"
},
{
"Value": "true",
"Key": "deletion_protection.enabled"
},
{
"Value": "",
"Key": "access_logs.s3.bucket"
}
]
}
```
**To enable access logs**
This example enables access logs for the specified load balancer. Note that the S3 bucket must exist in the same region as the load balancer and must have a policy attached that grants access to the Elastic Load Balancing service.
Command:
```
aws elbv2 modify-load-balancer-attributes --load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 --attributes Key=access_logs.s3.enabled,Value=true Key=access_logs.s3.bucket,Value=my-loadbalancer-logs Key=access_logs.s3.prefix,Value=myapp
```
Output:
```
{
"Attributes": [
{
"Value": "true",
"Key": "access_logs.s3.enabled"
},
{
"Value": "my-load-balancer-logs",
"Key": "access_logs.s3.bucket"
},
{
"Value": "myapp",
"Key": "access_logs.s3.prefix"
},
{
"Value": "60",
"Key": "idle_timeout.timeout_seconds"
},
{
"Value": "false",
"Key": "deletion_protection.enabled"
}
]
}
```
+ For API details, see [ModifyLoadBalancerAttributes](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/modify-load-balancer-attributes.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example modifes the Attributes of the specified load balancer.**
```
Edit-ELB2LoadBalancerAttribute -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -Attribute @{Key = 'deletion_protection.enabled'; Value = 'true'}
```
**Output:**
```
Key Value
--- -----
deletion_protection.enabled true
access_logs.s3.enabled false
access_logs.s3.bucket
access_logs.s3.prefix
idle_timeout.timeout_seconds 60
routing.http2.enabled true
routing.http.drop_invalid_header_fields.enabled false
```
+ For API details, see [ModifyLoadBalancerAttributes](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example modifes the Attributes of the specified load balancer.**
```
Edit-ELB2LoadBalancerAttribute -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -Attribute @{Key = 'deletion_protection.enabled'; Value = 'true'}
```
**Output:**
```
Key Value
--- -----
deletion_protection.enabled true
access_logs.s3.enabled false
access_logs.s3.bucket
access_logs.s3.prefix
idle_timeout.timeout_seconds 60
routing.http2.enabled true
routing.http.drop_invalid_header_fields.enabled false
```
+ For API details, see [ModifyLoadBalancerAttributes](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `ModifyRule` with a CLI
The following code examples show how to use `ModifyRule`.
------
#### [ CLI ]
**AWS CLI**
**To modify a rule**
The following `modify-rule` example updates the actions and conditions for the specified rule.
```
aws elbv2 modify-rule \
--actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067 \
--conditions Field=path-pattern,Values='/images/*'
--rule-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener-rule/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2/9683b2d02a6cabee
```
Output:
```
{
"Rules": [
{
"Priority": "10",
"Conditions": [
{
"Field": "path-pattern",
"Values": [
"/images/*"
]
}
],
"RuleArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener-rule/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2/9683b2d02a6cabee",
"IsDefault": false,
"Actions": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
"Type": "forward"
}
]
}
]
}
```
+ For API details, see [ModifyRule](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/modify-rule.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example modifes the specified Listener rule configurations.**
```
$newRuleCondition = [Amazon.ElasticLoadBalancingV2.Model.RuleCondition]@{
"PathPatternConfig" = @{
"Values" = "/login1","/login2","/login3"
}
"Field" = "path-pattern"
}
Edit-ELB2Rule -RuleArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/testALB/3e2f03b558e19676/1c84f02aec143e80/f4f51dfaa033a8cc' -Condition $newRuleCondition
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 10
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/testALB/3e2f03b558e19676/1c84f02aec143e80/f4f51dfaa033a8cc
```
+ For API details, see [ModifyRule](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example modifes the specified Listener rule configurations.**
```
$newRuleCondition = [Amazon.ElasticLoadBalancingV2.Model.RuleCondition]@{
"PathPatternConfig" = @{
"Values" = "/login1","/login2","/login3"
}
"Field" = "path-pattern"
}
Edit-ELB2Rule -RuleArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/testALB/3e2f03b558e19676/1c84f02aec143e80/f4f51dfaa033a8cc' -Condition $newRuleCondition
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 10
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/testALB/3e2f03b558e19676/1c84f02aec143e80/f4f51dfaa033a8cc
```
+ For API details, see [ModifyRule](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `ModifyTargetGroup` with a CLI
The following code examples show how to use `ModifyTargetGroup`.
------
#### [ CLI ]
**AWS CLI**
**To modify the health check configuration for a target group**
The following `modify-target-group` example changes the configuration of the health checks used to evaluate the health of the targets for the specified target group. Note that due to the way the CLI parses commas, you must surround the range for the `--matcher` option with single quotes instead of double quotes.
```
aws elbv2 modify-target-group \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-https-targets/2453ed029918f21f \
--health-check-protocol HTTPS \
--health-check-port 443 \
--matcher HttpCode='200,299'
```
Output:
```
{
"TargetGroups": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-https-targets/2453ed029918f21f",
"TargetGroupName": "my-https-targets",
"Protocol": "HTTPS",
"Port": 443,
"VpcId": "vpc-3ac0fb5f",
"HealthCheckProtocol": "HTTPS",
"HealthCheckPort": "443",
"HealthCheckEnabled": true,
"HealthCheckIntervalSeconds": 30,
"HealthCheckTimeoutSeconds": 5,
"HealthyThresholdCount": 5,
"UnhealthyThresholdCount": 2,
"Matcher": {
"HttpCode": "200,299"
},
"LoadBalancerArns": [
"arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188"
],
"TargetType": "instance",
"ProtocolVersion": "HTTP1",
"IpAddressType": "ipv4"
}
]
}
```
For more information, see [Target groups](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-target-groups.html) in the *Application Load Balancers Guide*.
+ For API details, see [ModifyTargetGroup](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/modify-target-group.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example modifes the properties of the specified Target Group.**
```
Edit-ELB2TargetGroup -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970' -HealthCheckIntervalSecond 60 -HealthCheckPath '/index.html' -HealthCheckPort 8080
```
**Output:**
```
HealthCheckEnabled : True
HealthCheckIntervalSeconds : 60
HealthCheckPath : /index.html
HealthCheckPort : 8080
HealthCheckProtocol : HTTP
HealthCheckTimeoutSeconds : 5
HealthyThresholdCount : 5
LoadBalancerArns : {}
Matcher : Amazon.ElasticLoadBalancingV2.Model.Matcher
Port : 80
Protocol : HTTP
TargetGroupArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970
TargetGroupName : test-tg
TargetType : instance
UnhealthyThresholdCount : 2
VpcId : vpc-2cfd7000
```
+ For API details, see [ModifyTargetGroup](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example modifes the properties of the specified Target Group.**
```
Edit-ELB2TargetGroup -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970' -HealthCheckIntervalSecond 60 -HealthCheckPath '/index.html' -HealthCheckPort 8080
```
**Output:**
```
HealthCheckEnabled : True
HealthCheckIntervalSeconds : 60
HealthCheckPath : /index.html
HealthCheckPort : 8080
HealthCheckProtocol : HTTP
HealthCheckTimeoutSeconds : 5
HealthyThresholdCount : 5
LoadBalancerArns : {}
Matcher : Amazon.ElasticLoadBalancingV2.Model.Matcher
Port : 80
Protocol : HTTP
TargetGroupArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970
TargetGroupName : test-tg
TargetType : instance
UnhealthyThresholdCount : 2
VpcId : vpc-2cfd7000
```
+ For API details, see [ModifyTargetGroup](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `ModifyTargetGroupAttributes` with a CLI
The following code examples show how to use `ModifyTargetGroupAttributes`.
------
#### [ CLI ]
**AWS CLI**
**To modify the deregistration delay timeout**
This example sets the deregistration delay timeout to the specified value for the specified target group.
Command:
```
aws elbv2 modify-target-group-attributes --target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067 --attributes Key=deregistration_delay.timeout_seconds,Value=600
```
Output:
```
{
"Attributes": [
{
"Value": "false",
"Key": "stickiness.enabled"
},
{
"Value": "600",
"Key": "deregistration_delay.timeout_seconds"
},
{
"Value": "lb_cookie",
"Key": "stickiness.type"
},
{
"Value": "86400",
"Key": "stickiness.lb_cookie.duration_seconds"
}
]
}
```
+ For API details, see [ModifyTargetGroupAttributes](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/modify-target-group-attributes.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example modifies the deregistration\$1delay attribute of the specified Target Group.**
```
Edit-ELB2TargetGroupAttribute -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970' -Attribute @{Key = 'deregistration_delay.timeout_seconds'; Value = 600}
```
**Output:**
```
Key Value
--- -----
stickiness.enabled false
deregistration_delay.timeout_seconds 600
stickiness.type lb_cookie
stickiness.lb_cookie.duration_seconds 86400
slow_start.duration_seconds 0
load_balancing.algorithm.type round_robin
```
+ For API details, see [ModifyTargetGroupAttributes](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example modifies the deregistration\$1delay attribute of the specified Target Group.**
```
Edit-ELB2TargetGroupAttribute -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970' -Attribute @{Key = 'deregistration_delay.timeout_seconds'; Value = 600}
```
**Output:**
```
Key Value
--- -----
stickiness.enabled false
deregistration_delay.timeout_seconds 600
stickiness.type lb_cookie
stickiness.lb_cookie.duration_seconds 86400
slow_start.duration_seconds 0
load_balancing.algorithm.type round_robin
```
+ For API details, see [ModifyTargetGroupAttributes](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `RegisterTargets` with a CLI
The following code examples show how to use `RegisterTargets`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example:
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
------
#### [ CLI ]
**AWS CLI**
**Example 1: To register targets with a target group by instance ID**
The following `register-targets` example registers the specified instances with a target group. The target group must have a target type of `instance`.
```
aws elbv2 register-targets \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067 \
--targets Id=i-1234567890abcdef0 Id=i-0abcdef1234567890
```
**Example 2: To register targets with a target group using port overrides**
The following `register-targets` example registers the specified instance with a target group using multiple ports. This enables you to register containers on the same instance as targets in the target group.
```
aws elbv2 register-targets \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-internal-targets/3bb63f11dfb0faf9 \
--targets Id=i-0598c7d356eba48d7,Port=80 Id=i-0598c7d356eba48d7,Port=766
```
**Example 3: To register targets with a target group by IP address**
The following `register-targets` example registers the specified IP addresses with a target group. The target group must have a target type of `ip`.
```
aws elbv2 register-targets \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-tcp-ip-targets/8518e899d173178f \
--targets Id=10.0.1.15 Id=10.0.1.23
```
**Example 4: To register a Lambda function as a target**
The following `register-targets` example registers the specified IP addresses with a target group. The target group must have a target type of `lambda`. You must grant Elastic Load Balancing permission to invoke the Lambda function.
```
aws elbv2 register-targets \
--target-group-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-tcp-ip-targets/8518e899d173178f \
--targets Id=arn:aws:lambda:us-west-2:123456789012:function:my-function
```
+ For API details, see [RegisterTargets](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/register-targets.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example registers 'i-0672a4c4cdeae3111' instance with the specified target group.**
```
Register-ELB2Target -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970' -Target @{Port = 80; Id = 'i-0672a4c4cdeae3111'}
```
+ For API details, see [RegisterTargets](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example registers 'i-0672a4c4cdeae3111' instance with the specified target group.**
```
Register-ELB2Target -TargetGroupArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/test-tg/a4e04b3688be1970' -Target @{Port = 80; Id = 'i-0672a4c4cdeae3111'}
```
+ For API details, see [RegisterTargets](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `RemoveListenerCertificates` with a CLI
The following code examples show how to use `RemoveListenerCertificates`.
------
#### [ CLI ]
**AWS CLI**
**To remove a certificate from a secure listener**
This example removes the specified certificate from the specified secure listener.
Command:
```
aws elbv2 remove-listener-certificates --listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 --certificates CertificateArn=arn:aws:acm:us-west-2:123456789012:certificate/5cc54884-f4a3-4072-80be-05b9ba72f705
```
+ For API details, see [RemoveListenerCertificates](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/remove-listener-certificates.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example removes specified certificate from the specified Target group.**
```
Remove-ELB2ListenerCertificate -Certificate @{CertificateArn = 'arn:aws:acm:us-east-1:123456789012:certificate/19478bd5-491d-47d4-b1d7-5217feba1d97'} -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2ListenerCertificate (RemoveListenerCertificates)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [RemoveListenerCertificates](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example removes specified certificate from the specified Target group.**
```
Remove-ELB2ListenerCertificate -Certificate @{CertificateArn = 'arn:aws:acm:us-east-1:123456789012:certificate/19478bd5-491d-47d4-b1d7-5217feba1d97'} -ListenerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2ListenerCertificate (RemoveListenerCertificates)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:listener/app/test-alb/3651b4394dd9a24f/3873f123b98f7618".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [RemoveListenerCertificates](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `RemoveTags` with a CLI
The following code examples show how to use `RemoveTags`.
------
#### [ CLI ]
**AWS CLI**
**To remove tags from a load balancer**
The following `remove-tags` example removes the `project` and `department` tags from the specified load balancer.
```
aws elbv2 remove-tags \
--resource-arns arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 \
--tag-keys project department
```
+ For API details, see [RemoveTags](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/remove-tags.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example removes the tag for the specified key. **
```
Remove-ELB2Tag -ResourceArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -TagKey 'productVersion'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Tag (RemoveTags)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [RemoveTags](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example removes the tag for the specified key. **
```
Remove-ELB2Tag -ResourceArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -TagKey 'productVersion'
```
**Output:**
```
Confirm
Are you sure you want to perform this action?
Performing the operation "Remove-ELB2Tag (RemoveTags)" on target "arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f".
[Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y
```
+ For API details, see [RemoveTags](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `SetIpAddressType` with a CLI
The following code examples show how to use `SetIpAddressType`.
------
#### [ CLI ]
**AWS CLI**
**To set the address type of a load balancer**
This example sets the address type of the specified load balancer to `dualstack`. The load balancer subnets must have associated IPv6 CIDR blocks.
Command:
```
aws elbv2 set-ip-address-type --load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 --ip-address-type dualstack
```
Output:
```
{
"IpAddressType": "dualstack"
}
```
+ For API details, see [SetIpAddressType](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/set-ip-address-type.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example changes Load balancer IP address type from 'IPv4' to 'DualStack'.**
```
Set-ELB2IpAddressType -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -IpAddressType dualstack
```
**Output:**
```
Value
-----
dualstack
```
+ For API details, see [SetIpAddressType](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example changes Load balancer IP address type from 'IPv4' to 'DualStack'.**
```
Set-ELB2IpAddressType -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -IpAddressType dualstack
```
**Output:**
```
Value
-----
dualstack
```
+ For API details, see [SetIpAddressType](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `SetRulePriorities` with a CLI
The following code examples show how to use `SetRulePriorities`.
------
#### [ CLI ]
**AWS CLI**
**To set the rule priority**
This example sets the priority of the specified rule.
Command:
```
aws elbv2 set-rule-priorities --rule-priorities RuleArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:listener-rule/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2/1291d13826f405c3,Priority=5
```
Output:
```
{
"Rules": [
{
"Priority": "5",
"Conditions": [
{
"Field": "path-pattern",
"Values": [
"/img/*"
]
}
],
"RuleArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener-rule/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2/1291d13826f405c3",
"IsDefault": false,
"Actions": [
{
"TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
"Type": "forward"
}
]
}
]
}
```
+ For API details, see [SetRulePriorities](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/set-rule-priorities.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example changes the priority of the specified listener rule.**
```
Set-ELB2RulePriority -RulePriority -RulePriority @{Priority = 11; RuleArn = 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/a4eb199fa5046f80/dbf4c6dcef3ec6f8'}
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 11
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/a4eb199fa5046f80/dbf4c6dcef3ec6f8
```
+ For API details, see [SetRulePriorities](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example changes the priority of the specified listener rule.**
```
Set-ELB2RulePriority -RulePriority -RulePriority @{Priority = 11; RuleArn = 'arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/a4eb199fa5046f80/dbf4c6dcef3ec6f8'}
```
**Output:**
```
Actions : {Amazon.ElasticLoadBalancingV2.Model.Action}
Conditions : {Amazon.ElasticLoadBalancingV2.Model.RuleCondition}
IsDefault : False
Priority : 11
RuleArn : arn:aws:elasticloadbalancing:us-east-1:123456789012:listener-rule/app/test-alb/3651b4394dd9a24f/a4eb199fa5046f80/dbf4c6dcef3ec6f8
```
+ For API details, see [SetRulePriorities](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `SetSecurityGroups` with a CLI
The following code examples show how to use `SetSecurityGroups`.
------
#### [ CLI ]
**AWS CLI**
**To associate a security group with a load balancer**
This example associates the specified security group with the specified load balancer.
Command:
```
aws elbv2 set-security-groups --load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 --security-groups sg-5943793c
```
Output:
```
{
"SecurityGroupIds": [
"sg-5943793c"
]
}
```
+ For API details, see [SetSecurityGroups](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/set-security-groups.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example adds security group 'sg-07c3414abb8811cbd' to the specified Load balancer.**
```
Set-ELB2SecurityGroup -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -SecurityGroup 'sg-07c3414abb8811cbd'
```
**Output:**
```
sg-07c3414abb8811cbd
```
+ For API details, see [SetSecurityGroups](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example adds security group 'sg-07c3414abb8811cbd' to the specified Load balancer.**
```
Set-ELB2SecurityGroup -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -SecurityGroup 'sg-07c3414abb8811cbd'
```
**Output:**
```
sg-07c3414abb8811cbd
```
+ For API details, see [SetSecurityGroups](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Use `SetSubnets` with a CLI
The following code examples show how to use `SetSubnets`.
------
#### [ CLI ]
**AWS CLI**
**To enable Availability Zones for a load balancer**
This example enables the Availability Zone for the specified subnet for the specified load balancer.
Command:
```
aws elbv2 set-subnets --load-balancer-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188 --subnets subnet-8360a9e7 subnet-b7d581c0
```
Output:
```
{
"AvailabilityZones": [
{
"SubnetId": "subnet-8360a9e7",
"ZoneName": "us-west-2a"
},
{
"SubnetId": "subnet-b7d581c0",
"ZoneName": "us-west-2b"
}
]
}
```
+ For API details, see [SetSubnets](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/elbv2/set-subnets.html) in *AWS CLI Command Reference*.
------
#### [ PowerShell ]
**Tools for PowerShell V4**
**Example 1: This example modifes the subnets of the specified Load balancer.**
```
Set-ELB2Subnet -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -Subnet 'subnet-7d8a0a51','subnet-c37a67a6'
```
**Output:**
```
LoadBalancerAddresses SubnetId ZoneName
--------------------- -------- --------
{} subnet-7d8a0a51 us-east-1c
{} subnet-c37a67a6 us-east-1b
```
+ For API details, see [SetSubnets](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*.
**Tools for PowerShell V5**
**Example 1: This example modifes the subnets of the specified Load balancer.**
```
Set-ELB2Subnet -LoadBalancerArn 'arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/test-alb/3651b4394dd9a24f' -Subnet 'subnet-7d8a0a51','subnet-c37a67a6'
```
**Output:**
```
LoadBalancerAddresses SubnetId ZoneName
--------------------- -------- --------
{} subnet-7d8a0a51 us-east-1c
{} subnet-c37a67a6 us-east-1b
```
+ For API details, see [SetSubnets](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*.
------
# Scenarios for Elastic Load Balancing - Version 2 using AWS SDKs
The following code examples show you how to implement common scenarios in Elastic Load Balancing - Version 2 with AWS SDKs. These scenarios show you how to accomplish specific tasks by calling multiple functions within Elastic Load Balancing - Version 2 or combined with other AWS services. Each scenario includes a link to the complete source code, where you can find instructions on how to set up and run the code.
Scenarios target an intermediate level of experience to help you understand service actions in context.
**Topics**
+ [Build and manage a resilient service](elastic-load-balancing-v2_example_cross_ResilientService_section.md)
+ [Getting started with Elastic Load Balancing](elastic-load-balancing-v2_example_elastic_load_balancing_v2_GettingStarted_058_section.md)
# Build and manage a resilient service using an AWS SDK
The following code examples show how to create a load-balanced web service that returns book, movie, and song recommendations. The example shows how the service responds to failures, and how to restructure the service for more resilience when failures occur.
+ Use an Amazon EC2 Auto Scaling group to create Amazon Elastic Compute Cloud (Amazon EC2) instances based on a launch template and to keep the number of instances in a specified range.
+ Handle and distribute HTTP requests with Elastic Load Balancing.
+ Monitor the health of instances in an Auto Scaling group and forward requests only to healthy instances.
+ Run a Python web server on each EC2 instance to handle HTTP requests. The web server responds with recommendations and health checks.
+ Simulate a recommendation service with an Amazon DynamoDB table.
+ Control web server response to requests and health checks by updating AWS Systems Manager parameters.
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/ResilientService#code-examples).
Run the interactive scenario at a command prompt.
```
static async Task Main(string[] args)
{
_configuration = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("settings.json") // Load settings from .json file.
.AddJsonFile("settings.local.json",
true) // Optionally, load local settings.
.Build();
// Set up dependency injection for the AWS services.
using var host = Host.CreateDefaultBuilder(args)
.ConfigureLogging(logging =>
logging.AddFilter("System", LogLevel.Debug)
.AddFilter("Microsoft", LogLevel.Information)
.AddFilter("Microsoft", LogLevel.Trace))
.ConfigureServices((_, services) =>
services.AddAWSService()
.AddAWSService()
.AddAWSService()
.AddAWSService()
.AddAWSService()
.AddAWSService()
.AddTransient()
.AddTransient()
.AddTransient()
.AddTransient()
.AddSingleton(_configuration)
)
.Build();
ServicesSetup(host);
ResourcesSetup();
try
{
Console.WriteLine(new string('-', 80));
Console.WriteLine("Welcome to the Resilient Architecture Example Scenario.");
Console.WriteLine(new string('-', 80));
await Deploy(true);
Console.WriteLine("Now let's begin the scenario.");
Console.WriteLine(new string('-', 80));
await Demo(true);
Console.WriteLine(new string('-', 80));
Console.WriteLine("Finally, let's clean up our resources.");
Console.WriteLine(new string('-', 80));
await DestroyResources(true);
Console.WriteLine(new string('-', 80));
Console.WriteLine("Resilient Architecture Example Scenario is complete.");
Console.WriteLine(new string('-', 80));
}
catch (Exception ex)
{
Console.WriteLine(new string('-', 80));
Console.WriteLine($"There was a problem running the scenario: {ex.Message}");
await DestroyResources(true);
Console.WriteLine(new string('-', 80));
}
}
///
/// Setup any common resources, also used for integration testing.
///
public static void ResourcesSetup()
{
_httpClient = new HttpClient();
}
///
/// Populate the services for use within the console application.
///
/// The services host.
private static void ServicesSetup(IHost host)
{
_elasticLoadBalancerWrapper = host.Services.GetRequiredService();
_iamClient = host.Services.GetRequiredService();
_recommendations = host.Services.GetRequiredService();
_autoScalerWrapper = host.Services.GetRequiredService();
_smParameterWrapper = host.Services.GetRequiredService();
}
///
/// Deploy necessary resources for the scenario.
///
/// True to run as interactive.
/// True if successful.
public static async Task Deploy(bool interactive)
{
var protocol = "HTTP";
var port = 80;
var sshPort = 22;
Console.WriteLine(
"\nFor this demo, we'll use the AWS SDK for .NET to create several AWS resources\n" +
"to set up a load-balanced web service endpoint and explore some ways to make it resilient\n" +
"against various kinds of failures.\n\n" +
"Some of the resources create by this demo are:\n");
Console.WriteLine(
"\t* A DynamoDB table that the web service depends on to provide book, movie, and song recommendations.");
Console.WriteLine(
"\t* An EC2 launch template that defines EC2 instances that each contain a Python web server.");
Console.WriteLine(
"\t* An EC2 Auto Scaling group that manages EC2 instances across several Availability Zones.");
Console.WriteLine(
"\t* An Elastic Load Balancing (ELB) load balancer that targets the Auto Scaling group to distribute requests.");
Console.WriteLine(new string('-', 80));
Console.WriteLine("Press Enter when you're ready to start deploying resources.");
if (interactive)
Console.ReadLine();
// Create and populate the DynamoDB table.
var databaseTableName = _configuration["databaseName"];
var recommendationsPath = Path.Join(_configuration["resourcePath"],
"recommendations_objects.json");
Console.WriteLine($"Creating and populating a DynamoDB table named {databaseTableName}.");
await _recommendations.CreateDatabaseWithName(databaseTableName);
await _recommendations.PopulateDatabase(databaseTableName, recommendationsPath);
Console.WriteLine(new string('-', 80));
// Create the EC2 Launch Template.
Console.WriteLine(
$"Creating an EC2 launch template that runs 'server_startup_script.sh' when an instance starts.\n"
+ "\nThis script starts a Python web server defined in the `server.py` script. The web server\n"
+ "listens to HTTP requests on port 80 and responds to requests to '/' and to '/healthcheck'.\n"
+ "For demo purposes, this server is run as the root user. In production, the best practice is to\n"
+ "run a web server, such as Apache, with least-privileged credentials.");
Console.WriteLine(
"\nThe template also defines an IAM policy that each instance uses to assume a role that grants\n"
+ "permissions to access the DynamoDB recommendation table and Systems Manager parameters\n"
+ "that control the flow of the demo.");
var startupScriptPath = Path.Join(_configuration["resourcePath"],
"server_startup_script.sh");
var instancePolicyPath = Path.Join(_configuration["resourcePath"],
"instance_policy.json");
await _autoScalerWrapper.CreateTemplate(startupScriptPath, instancePolicyPath);
Console.WriteLine(new string('-', 80));
Console.WriteLine(
"Creating an EC2 Auto Scaling group that maintains three EC2 instances, each in a different\n"
+ "Availability Zone.\n");
var zones = await _autoScalerWrapper.DescribeAvailabilityZones();
await _autoScalerWrapper.CreateGroupOfSize(3, _autoScalerWrapper.GroupName, zones);
Console.WriteLine(new string('-', 80));
Console.WriteLine(
"At this point, you have EC2 instances created. Once each instance starts, it listens for\n"
+ "HTTP requests. You can see these instances in the console or continue with the demo.\n");
Console.WriteLine(new string('-', 80));
Console.WriteLine("Press Enter when you're ready to continue.");
if (interactive)
Console.ReadLine();
Console.WriteLine("Creating variables that control the flow of the demo.");
await _smParameterWrapper.Reset();
Console.WriteLine(
"\nCreating an Elastic Load Balancing target group and load balancer. The target group\n"
+ "defines how the load balancer connects to instances. The load balancer provides a\n"
+ "single endpoint where clients connect and dispatches requests to instances in the group.");
var defaultVpc = await _autoScalerWrapper.GetDefaultVpc();
var subnets = await _autoScalerWrapper.GetAllVpcSubnetsForZones(defaultVpc.VpcId, zones);
var subnetIds = subnets.Select(s => s.SubnetId).ToList();
var targetGroup = await _elasticLoadBalancerWrapper.CreateTargetGroupOnVpc(_elasticLoadBalancerWrapper.TargetGroupName, protocol, port, defaultVpc.VpcId);
await _elasticLoadBalancerWrapper.CreateLoadBalancerAndListener(_elasticLoadBalancerWrapper.LoadBalancerName, subnetIds, targetGroup);
await _autoScalerWrapper.AttachLoadBalancerToGroup(_autoScalerWrapper.GroupName, targetGroup.TargetGroupArn);
Console.WriteLine("\nVerifying access to the load balancer endpoint...");
var endPoint = await _elasticLoadBalancerWrapper.GetEndpointForLoadBalancerByName(_elasticLoadBalancerWrapper.LoadBalancerName);
var loadBalancerAccess = await _elasticLoadBalancerWrapper.VerifyLoadBalancerEndpoint(endPoint);
if (!loadBalancerAccess)
{
Console.WriteLine("\nCouldn't connect to the load balancer, verifying that the port is open...");
var ipString = await _httpClient.GetStringAsync("https://checkip.amazonaws.com");
ipString = ipString.Trim();
var defaultSecurityGroup = await _autoScalerWrapper.GetDefaultSecurityGroupForVpc(defaultVpc);
var portIsOpen = _autoScalerWrapper.VerifyInboundPortForGroup(defaultSecurityGroup, port, ipString);
var sshPortIsOpen = _autoScalerWrapper.VerifyInboundPortForGroup(defaultSecurityGroup, sshPort, ipString);
if (!portIsOpen)
{
Console.WriteLine(
"\nFor this example to work, the default security group for your default VPC must\n"
+ "allows access from this computer. You can either add it automatically from this\n"
+ "example or add it yourself using the AWS Management Console.\n");
if (!interactive || GetYesNoResponse(
"Do you want to add a rule to the security group to allow inbound traffic from your computer's IP address?"))
{
await _autoScalerWrapper.OpenInboundPort(defaultSecurityGroup.GroupId, port, ipString);
}
}
if (!sshPortIsOpen)
{
if (!interactive || GetYesNoResponse(
"Do you want to add a rule to the security group to allow inbound SSH traffic for debugging from your computer's IP address?"))
{
await _autoScalerWrapper.OpenInboundPort(defaultSecurityGroup.GroupId, sshPort, ipString);
}
}
loadBalancerAccess = await _elasticLoadBalancerWrapper.VerifyLoadBalancerEndpoint(endPoint);
}
if (loadBalancerAccess)
{
Console.WriteLine("Your load balancer is ready. You can access it by browsing to:");
Console.WriteLine($"\thttp://{endPoint}\n");
}
else
{
Console.WriteLine(
"\nCouldn't get a successful response from the load balancer endpoint. Troubleshoot by\n"
+ "manually verifying that your VPC and security group are configured correctly and that\n"
+ "you can successfully make a GET request to the load balancer endpoint:\n");
Console.WriteLine($"\thttp://{endPoint}\n");
}
Console.WriteLine(new string('-', 80));
Console.WriteLine("Press Enter when you're ready to continue with the demo.");
if (interactive)
Console.ReadLine();
return true;
}
///
/// Demonstrate the steps of the scenario.
///
/// True to run as an interactive scenario.
/// Async task.
public static async Task Demo(bool interactive)
{
var ssmOnlyPolicy = Path.Join(_configuration["resourcePath"],
"ssm_only_policy.json");
Console.WriteLine(new string('-', 80));
Console.WriteLine("Resetting parameters to starting values for demo.");
await _smParameterWrapper.Reset();
Console.WriteLine("\nThis part of the demonstration shows how to toggle different parts of the system\n" +
"to create situations where the web service fails, and shows how using a resilient\n" +
"architecture can keep the web service running in spite of these failures.");
Console.WriteLine(new string('-', 88));
Console.WriteLine("At the start, the load balancer endpoint returns recommendations and reports that all targets are healthy.");
if (interactive)
await DemoActionChoices();
Console.WriteLine($"The web service running on the EC2 instances gets recommendations by querying a DynamoDB table.\n" +
$"The table name is contained in a Systems Manager parameter named '{_smParameterWrapper.TableParameter}'.\n" +
$"To simulate a failure of the recommendation service, let's set this parameter to name a non-existent table.\n");
await _smParameterWrapper.PutParameterByName(_smParameterWrapper.TableParameter, "this-is-not-a-table");
Console.WriteLine("\nNow, sending a GET request to the load balancer endpoint returns a failure code. But, the service reports as\n" +
"healthy to the load balancer because shallow health checks don't check for failure of the recommendation service.");
if (interactive)
await DemoActionChoices();
Console.WriteLine("Instead of failing when the recommendation service fails, the web service can return a static response.");
Console.WriteLine("While this is not a perfect solution, it presents the customer with a somewhat better experience than failure.");
await _smParameterWrapper.PutParameterByName(_smParameterWrapper.FailureResponseParameter, "static");
Console.WriteLine("\nNow, sending a GET request to the load balancer endpoint returns a static response.");
Console.WriteLine("The service still reports as healthy because health checks are still shallow.");
if (interactive)
await DemoActionChoices();
Console.WriteLine("Let's reinstate the recommendation service.\n");
await _smParameterWrapper.PutParameterByName(_smParameterWrapper.TableParameter, _smParameterWrapper.TableName);
Console.WriteLine(
"\nLet's also substitute bad credentials for one of the instances in the target group so that it can't\n" +
"access the DynamoDB recommendation table.\n"
);
await _autoScalerWrapper.CreateInstanceProfileWithName(
_autoScalerWrapper.BadCredsPolicyName,
_autoScalerWrapper.BadCredsRoleName,
_autoScalerWrapper.BadCredsProfileName,
ssmOnlyPolicy,
new List { "AmazonSSMManagedInstanceCore" }
);
var instances = await _autoScalerWrapper.GetInstancesByGroupName(_autoScalerWrapper.GroupName);
var badInstanceId = instances.First();
var instanceProfile = await _autoScalerWrapper.GetInstanceProfile(badInstanceId);
Console.WriteLine(
$"Replacing the profile for instance {badInstanceId} with a profile that contains\n" +
"bad credentials...\n"
);
await _autoScalerWrapper.ReplaceInstanceProfile(
badInstanceId,
_autoScalerWrapper.BadCredsProfileName,
instanceProfile.AssociationId
);
Console.WriteLine(
"Now, sending a GET request to the load balancer endpoint returns either a recommendation or a static response,\n" +
"depending on which instance is selected by the load balancer.\n"
);
if (interactive)
await DemoActionChoices();
Console.WriteLine("\nLet's implement a deep health check. For this demo, a deep health check tests whether");
Console.WriteLine("the web service can access the DynamoDB table that it depends on for recommendations. Note that");
Console.WriteLine("the deep health check is only for ELB routing and not for Auto Scaling instance health.");
Console.WriteLine("This kind of deep health check is not recommended for Auto Scaling instance health, because it");
Console.WriteLine("risks accidental termination of all instances in the Auto Scaling group when a dependent service fails.");
Console.WriteLine("\nBy implementing deep health checks, the load balancer can detect when one of the instances is failing");
Console.WriteLine("and take that instance out of rotation.");
await _smParameterWrapper.PutParameterByName(_smParameterWrapper.HealthCheckParameter, "deep");
Console.WriteLine($"\nNow, checking target health indicates that the instance with bad credentials ({badInstanceId})");
Console.WriteLine("is unhealthy. Note that it might take a minute or two for the load balancer to detect the unhealthy");
Console.WriteLine("instance. Sending a GET request to the load balancer endpoint always returns a recommendation, because");
Console.WriteLine("the load balancer takes unhealthy instances out of its rotation.");
if (interactive)
await DemoActionChoices();
Console.WriteLine("\nBecause the instances in this demo are controlled by an auto scaler, the simplest way to fix an unhealthy");
Console.WriteLine("instance is to terminate it and let the auto scaler start a new instance to replace it.");
await _autoScalerWrapper.TryTerminateInstanceById(badInstanceId);
Console.WriteLine($"\nEven while the instance is terminating and the new instance is starting, sending a GET");
Console.WriteLine("request to the web service continues to get a successful recommendation response because");
Console.WriteLine("starts and reports as healthy, it is included in the load balancing rotation.");
Console.WriteLine("Note that terminating and replacing an instance typically takes several minutes, during which time you");
Console.WriteLine("can see the changing health check status until the new instance is running and healthy.");
if (interactive)
await DemoActionChoices();
Console.WriteLine("\nIf the recommendation service fails now, deep health checks mean all instances report as unhealthy.");
await _smParameterWrapper.PutParameterByName(_smParameterWrapper.TableParameter, "this-is-not-a-table");
Console.WriteLine($"\nWhen all instances are unhealthy, the load balancer continues to route requests even to");
Console.WriteLine("unhealthy instances, allowing them to fail open and return a static response rather than fail");
Console.WriteLine("closed and report failure to the customer.");
if (interactive)
await DemoActionChoices();
await _smParameterWrapper.Reset();
Console.WriteLine(new string('-', 80));
return true;
}
///
/// Clean up the resources from the scenario.
///
/// True to ask the user for cleanup.
/// Async task.
public static async Task DestroyResources(bool interactive)
{
Console.WriteLine(new string('-', 80));
Console.WriteLine(
"To keep things tidy and to avoid unwanted charges on your account, we can clean up all AWS resources\n" +
"that were created for this demo."
);
if (!interactive || GetYesNoResponse("Do you want to clean up all demo resources? (y/n) "))
{
await _elasticLoadBalancerWrapper.DeleteLoadBalancerByName(_elasticLoadBalancerWrapper.LoadBalancerName);
await _elasticLoadBalancerWrapper.DeleteTargetGroupByName(_elasticLoadBalancerWrapper.TargetGroupName);
await _autoScalerWrapper.TerminateAndDeleteAutoScalingGroupWithName(_autoScalerWrapper.GroupName);
await _autoScalerWrapper.DeleteKeyPairByName(_autoScalerWrapper.KeyPairName);
await _autoScalerWrapper.DeleteTemplateByName(_autoScalerWrapper.LaunchTemplateName);
await _autoScalerWrapper.DeleteInstanceProfile(
_autoScalerWrapper.BadCredsProfileName,
_autoScalerWrapper.BadCredsRoleName
);
await _recommendations.DestroyDatabaseByName(_recommendations.TableName);
}
else
{
Console.WriteLine(
"Ok, we'll leave the resources intact.\n" +
"Don't forget to delete them when you're done with them or you might incur unexpected charges."
);
}
Console.WriteLine(new string('-', 80));
return true;
}
```
Create a class that wraps Auto Scaling and Amazon EC2 actions.
```
///
/// Encapsulates Amazon EC2 Auto Scaling and EC2 management methods.
///
public class AutoScalerWrapper
{
private readonly IAmazonAutoScaling _amazonAutoScaling;
private readonly IAmazonEC2 _amazonEc2;
private readonly IAmazonSimpleSystemsManagement _amazonSsm;
private readonly IAmazonIdentityManagementService _amazonIam;
private readonly ILogger _logger;
private readonly string _instanceType = "";
private readonly string _amiParam = "";
private readonly string _launchTemplateName = "";
private readonly string _groupName = "";
private readonly string _instancePolicyName = "";
private readonly string _instanceRoleName = "";
private readonly string _instanceProfileName = "";
private readonly string _badCredsProfileName = "";
private readonly string _badCredsRoleName = "";
private readonly string _badCredsPolicyName = "";
private readonly string _keyPairName = "";
public string GroupName => _groupName;
public string KeyPairName => _keyPairName;
public string LaunchTemplateName => _launchTemplateName;
public string InstancePolicyName => _instancePolicyName;
public string BadCredsProfileName => _badCredsProfileName;
public string BadCredsRoleName => _badCredsRoleName;
public string BadCredsPolicyName => _badCredsPolicyName;
///
/// Constructor for the AutoScalerWrapper.
///
/// The injected AutoScaling client.
/// The injected EC2 client.
/// The injected IAM client.
/// The injected SSM client.
public AutoScalerWrapper(
IAmazonAutoScaling amazonAutoScaling,
IAmazonEC2 amazonEc2,
IAmazonSimpleSystemsManagement amazonSsm,
IAmazonIdentityManagementService amazonIam,
IConfiguration configuration,
ILogger logger)
{
_amazonAutoScaling = amazonAutoScaling;
_amazonEc2 = amazonEc2;
_amazonSsm = amazonSsm;
_amazonIam = amazonIam;
_logger = logger;
var prefix = configuration["resourcePrefix"];
_instanceType = configuration["instanceType"];
_amiParam = configuration["amiParam"];
_launchTemplateName = prefix + "-template";
_groupName = prefix + "-group";
_instancePolicyName = prefix + "-pol";
_instanceRoleName = prefix + "-role";
_instanceProfileName = prefix + "-prof";
_badCredsPolicyName = prefix + "-bc-pol";
_badCredsRoleName = prefix + "-bc-role";
_badCredsProfileName = prefix + "-bc-prof";
_keyPairName = prefix + "-key-pair";
}
///
/// Create a policy, role, and profile that is associated with instances with a specified name.
/// An instance's associated profile defines a role that is assumed by the
/// instance.The role has attached policies that specify the AWS permissions granted to
/// clients that run on the instance.
///
/// Name to use for the policy.
/// Name to use for the role.
/// Name to use for the profile.
/// Path to a policy file for SSM.
/// AWS Managed policies to be attached to the role.
/// The Arn of the profile.
public async Task CreateInstanceProfileWithName(
string policyName,
string roleName,
string profileName,
string ssmOnlyPolicyFile,
List? awsManagedPolicies = null)
{
var assumeRoleDoc = "{" +
"\"Version\": \"2012-10-17\"," +
"\"Statement\": [{" +
"\"Effect\": \"Allow\"," +
"\"Principal\": {" +
"\"Service\": [" +
"\"ec2.amazonaws.com\"" +
"]" +
"}," +
"\"Action\": \"sts:AssumeRole\"" +
"}]" +
"}";
var policyDocument = await File.ReadAllTextAsync(ssmOnlyPolicyFile);
var policyArn = "";
try
{
var createPolicyResult = await _amazonIam.CreatePolicyAsync(
new CreatePolicyRequest
{
PolicyName = policyName,
PolicyDocument = policyDocument
});
policyArn = createPolicyResult.Policy.Arn;
}
catch (EntityAlreadyExistsException)
{
// The policy already exists, so we look it up to get the Arn.
var policiesPaginator = _amazonIam.Paginators.ListPolicies(
new ListPoliciesRequest()
{
Scope = PolicyScopeType.Local
});
// Get the entire list using the paginator.
await foreach (var policy in policiesPaginator.Policies)
{
if (policy.PolicyName.Equals(policyName))
{
policyArn = policy.Arn;
}
}
if (policyArn == null)
{
throw new InvalidOperationException("Policy not found");
}
}
try
{
await _amazonIam.CreateRoleAsync(new CreateRoleRequest()
{
RoleName = roleName,
AssumeRolePolicyDocument = assumeRoleDoc,
});
await _amazonIam.AttachRolePolicyAsync(new AttachRolePolicyRequest()
{
RoleName = roleName,
PolicyArn = policyArn
});
if (awsManagedPolicies != null)
{
foreach (var awsPolicy in awsManagedPolicies)
{
await _amazonIam.AttachRolePolicyAsync(new AttachRolePolicyRequest()
{
PolicyArn = $"arn:aws:iam::aws:policy/{awsPolicy}",
RoleName = roleName
});
}
}
}
catch (EntityAlreadyExistsException)
{
Console.WriteLine("Role already exists.");
}
string profileArn = "";
try
{
var profileCreateResponse = await _amazonIam.CreateInstanceProfileAsync(
new CreateInstanceProfileRequest()
{
InstanceProfileName = profileName
});
// Allow time for the profile to be ready.
profileArn = profileCreateResponse.InstanceProfile.Arn;
Thread.Sleep(10000);
await _amazonIam.AddRoleToInstanceProfileAsync(
new AddRoleToInstanceProfileRequest()
{
InstanceProfileName = profileName,
RoleName = roleName
});
}
catch (EntityAlreadyExistsException)
{
Console.WriteLine("Policy already exists.");
var profileGetResponse = await _amazonIam.GetInstanceProfileAsync(
new GetInstanceProfileRequest()
{
InstanceProfileName = profileName
});
profileArn = profileGetResponse.InstanceProfile.Arn;
}
return profileArn;
}
///
/// Create a new key pair and save the file.
///
/// The name of the new key pair.
/// Async task.
public async Task CreateKeyPair(string newKeyPairName)
{
try
{
var keyResponse = await _amazonEc2.CreateKeyPairAsync(
new CreateKeyPairRequest() { KeyName = newKeyPairName });
await File.WriteAllTextAsync($"{newKeyPairName}.pem",
keyResponse.KeyPair.KeyMaterial);
Console.WriteLine($"Created key pair {newKeyPairName}.");
}
catch (AlreadyExistsException)
{
Console.WriteLine("Key pair already exists.");
}
}
///
/// Delete the key pair and file by name.
///
/// The key pair to delete.
/// Async task.
public async Task DeleteKeyPairByName(string deleteKeyPairName)
{
try
{
await _amazonEc2.DeleteKeyPairAsync(
new DeleteKeyPairRequest() { KeyName = deleteKeyPairName });
File.Delete($"{deleteKeyPairName}.pem");
}
catch (FileNotFoundException)
{
Console.WriteLine($"Key pair {deleteKeyPairName} not found.");
}
}
///
/// Creates an Amazon EC2 launch template to use with Amazon EC2 Auto Scaling.
/// The launch template specifies a Bash script in its user data field that runs after
/// the instance is started. This script installs the Python packages and starts a Python
/// web server on the instance.
///
/// The path to a Bash script file that is run.
/// The path to a permissions policy to create and attach to the profile.
/// The template object.
public async Task CreateTemplate(string startupScriptPath, string instancePolicyPath)
{
try
{
await CreateKeyPair(_keyPairName);
await CreateInstanceProfileWithName(_instancePolicyName, _instanceRoleName,
_instanceProfileName, instancePolicyPath);
var startServerText = await File.ReadAllTextAsync(startupScriptPath);
var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(startServerText);
var amiLatest = await _amazonSsm.GetParameterAsync(
new GetParameterRequest() { Name = _amiParam });
var amiId = amiLatest.Parameter.Value;
var launchTemplateResponse = await _amazonEc2.CreateLaunchTemplateAsync(
new CreateLaunchTemplateRequest()
{
LaunchTemplateName = _launchTemplateName,
LaunchTemplateData = new RequestLaunchTemplateData()
{
InstanceType = _instanceType,
ImageId = amiId,
IamInstanceProfile =
new
LaunchTemplateIamInstanceProfileSpecificationRequest()
{
Name = _instanceProfileName
},
KeyName = _keyPairName,
UserData = System.Convert.ToBase64String(plainTextBytes)
}
});
return launchTemplateResponse.LaunchTemplate;
}
catch (AmazonEC2Exception ec2Exception)
{
if (ec2Exception.ErrorCode == "InvalidLaunchTemplateName.AlreadyExistsException")
{
_logger.LogError($"Could not create the template, the name {_launchTemplateName} already exists. " +
$"Please try again with a unique name.");
}
throw;
}
catch (Exception ex)
{
_logger.LogError($"An error occurred while creating the template.: {ex.Message}");
throw;
}
}
///
/// Get a list of Availability Zones in the AWS Region of the Amazon EC2 Client.
///
/// A list of availability zones.
public async Task> DescribeAvailabilityZones()
{
try
{
var zoneResponse = await _amazonEc2.DescribeAvailabilityZonesAsync(
new DescribeAvailabilityZonesRequest());
return zoneResponse.AvailabilityZones.Select(z => z.ZoneName).ToList();
}
catch (AmazonEC2Exception ec2Exception)
{
_logger.LogError($"An Amazon EC2 error occurred while listing availability zones.: {ec2Exception.Message}");
throw;
}
catch (Exception ex)
{
_logger.LogError($"An error occurred while listing availability zones.: {ex.Message}");
throw;
}
}
///
/// Create an EC2 Auto Scaling group of a specified size and name.
///
/// The size for the group.
/// The name for the group.
/// The availability zones for the group.
/// Async task.
public async Task CreateGroupOfSize(int groupSize, string groupName, List availabilityZones)
{
try
{
await _amazonAutoScaling.CreateAutoScalingGroupAsync(
new CreateAutoScalingGroupRequest()
{
AutoScalingGroupName = groupName,
AvailabilityZones = availabilityZones,
LaunchTemplate =
new Amazon.AutoScaling.Model.LaunchTemplateSpecification()
{
LaunchTemplateName = _launchTemplateName,
Version = "$Default"
},
MaxSize = groupSize,
MinSize = groupSize
});
Console.WriteLine($"Created EC2 Auto Scaling group {groupName} with size {groupSize}.");
}
catch (EntityAlreadyExistsException)
{
Console.WriteLine($"EC2 Auto Scaling group {groupName} already exists.");
}
}
///
/// Get the default VPC for the account.
///
/// The default VPC object.
public async Task GetDefaultVpc()
{
try
{
var vpcResponse = await _amazonEc2.DescribeVpcsAsync(
new DescribeVpcsRequest()
{
Filters = new List()
{
new("is-default", new List() { "true" })
}
});
return vpcResponse.Vpcs[0];
}
catch (AmazonEC2Exception ec2Exception)
{
if (ec2Exception.ErrorCode == "UnauthorizedOperation")
{
_logger.LogError(ec2Exception, $"You do not have the necessary permissions to describe VPCs.");
}
throw;
}
catch (Exception ex)
{
_logger.LogError(ex, $"An error occurred while describing the vpcs.: {ex.Message}");
throw;
}
}
///
/// Get all the subnets for a Vpc in a set of availability zones.
///
/// The Id of the Vpc.
/// The list of availability zones.
/// The collection of subnet objects.
public async Task> GetAllVpcSubnetsForZones(string vpcId, List availabilityZones)
{
try
{
var subnets = new List();
var subnetPaginator = _amazonEc2.Paginators.DescribeSubnets(
new DescribeSubnetsRequest()
{
Filters = new List()
{
new("vpc-id", new List() { vpcId }),
new("availability-zone", availabilityZones),
new("default-for-az", new List() { "true" })
}
});
// Get the entire list using the paginator.
await foreach (var subnet in subnetPaginator.Subnets)
{
subnets.Add(subnet);
}
return subnets;
}
catch (AmazonEC2Exception ec2Exception)
{
if (ec2Exception.ErrorCode == "InvalidVpcID.NotFound")
{
_logger.LogError(ec2Exception, $"The specified VPC ID {vpcId} does not exist.");
}
throw;
}
catch (Exception ex)
{
_logger.LogError(ex, $"An error occurred while describing the subnets.: {ex.Message}");
throw;
}
}
///
/// Delete a launch template by name.
///
/// The name of the template to delete.
/// Async task.
public async Task DeleteTemplateByName(string templateName)
{
try
{
await _amazonEc2.DeleteLaunchTemplateAsync(
new DeleteLaunchTemplateRequest()
{
LaunchTemplateName = templateName
});
}
catch (AmazonEC2Exception ec2Exception)
{
if (ec2Exception.ErrorCode == "InvalidLaunchTemplateName.NotFoundException")
{
_logger.LogError(
$"Could not delete the template, the name {_launchTemplateName} was not found.");
}
throw;
}
catch (Exception ex)
{
_logger.LogError($"An error occurred while deleting the template.: {ex.Message}");
throw;
}
}
///
/// Detaches a role from an instance profile, detaches policies from the role,
/// and deletes all the resources.
///
/// The name of the profile to delete.
/// The name of the role to delete.
/// Async task.
public async Task DeleteInstanceProfile(string profileName, string roleName)
{
try
{
await _amazonIam.RemoveRoleFromInstanceProfileAsync(
new RemoveRoleFromInstanceProfileRequest()
{
InstanceProfileName = profileName,
RoleName = roleName
});
await _amazonIam.DeleteInstanceProfileAsync(
new DeleteInstanceProfileRequest() { InstanceProfileName = profileName });
var attachedPolicies = await _amazonIam.ListAttachedRolePoliciesAsync(
new ListAttachedRolePoliciesRequest() { RoleName = roleName });
foreach (var policy in attachedPolicies.AttachedPolicies)
{
await _amazonIam.DetachRolePolicyAsync(
new DetachRolePolicyRequest()
{
RoleName = roleName,
PolicyArn = policy.PolicyArn
});
// Delete the custom policies only.
if (!policy.PolicyArn.StartsWith("arn:aws:iam::aws"))
{
await _amazonIam.DeletePolicyAsync(
new Amazon.IdentityManagement.Model.DeletePolicyRequest()
{
PolicyArn = policy.PolicyArn
});
}
}
await _amazonIam.DeleteRoleAsync(
new DeleteRoleRequest() { RoleName = roleName });
}
catch (NoSuchEntityException)
{
Console.WriteLine($"Instance profile {profileName} does not exist.");
}
}
///
/// Gets data about the instances in an EC2 Auto Scaling group by its group name.
///
/// The name of the auto scaling group.
/// A collection of instance Ids.
public async Task> GetInstancesByGroupName(string group)
{
var instanceResponse = await _amazonAutoScaling.DescribeAutoScalingGroupsAsync(
new DescribeAutoScalingGroupsRequest()
{
AutoScalingGroupNames = new List() { group }
});
var instanceIds = instanceResponse.AutoScalingGroups.SelectMany(
g => g.Instances.Select(i => i.InstanceId));
return instanceIds;
}
///
/// Get the instance profile association data for an instance.
///
/// The Id of the instance.
/// Instance profile associations data.
public async Task GetInstanceProfile(string instanceId)
{
try
{
var response = await _amazonEc2.DescribeIamInstanceProfileAssociationsAsync(
new DescribeIamInstanceProfileAssociationsRequest()
{
Filters = new List()
{
new("instance-id", new List() { instanceId })
},
});
return response.IamInstanceProfileAssociations[0];
}
catch (AmazonEC2Exception ec2Exception)
{
if (ec2Exception.ErrorCode == "InvalidInstanceID.NotFound")
{
_logger.LogError(ec2Exception, $"Instance {instanceId} not found");
}
throw;
}
catch (Exception ex)
{
_logger.LogError(ex, $"An error occurred while creating the template.: {ex.Message}");
throw;
}
}
///
/// Replace the profile associated with a running instance. After the profile is replaced, the instance
/// is rebooted to ensure that it uses the new profile. When the instance is ready, Systems Manager is
/// used to restart the Python web server.
///
/// The Id of the instance to update.
/// The name of the new profile to associate with the specified instance.
/// The Id of the existing profile association for the instance.
/// Async task.
public async Task ReplaceInstanceProfile(string instanceId, string credsProfileName, string associationId)
{
try
{
await _amazonEc2.ReplaceIamInstanceProfileAssociationAsync(
new ReplaceIamInstanceProfileAssociationRequest()
{
AssociationId = associationId,
IamInstanceProfile = new IamInstanceProfileSpecification()
{
Name = credsProfileName
}
});
// Allow time before resetting.
Thread.Sleep(25000);
await _amazonEc2.RebootInstancesAsync(
new RebootInstancesRequest(new List() { instanceId }));
Thread.Sleep(25000);
var instanceReady = false;
var retries = 5;
while (retries-- > 0 && !instanceReady)
{
var instancesPaginator =
_amazonSsm.Paginators.DescribeInstanceInformation(
new DescribeInstanceInformationRequest());
// Get the entire list using the paginator.
await foreach (var instance in instancesPaginator.InstanceInformationList)
{
instanceReady = instance.InstanceId == instanceId;
if (instanceReady)
{
break;
}
}
}
Console.WriteLine("Waiting for instance to be running.");
await WaitForInstanceState(instanceId, InstanceStateName.Running);
Console.WriteLine("Instance ready.");
Console.WriteLine($"Sending restart command to instance {instanceId}");
await _amazonSsm.SendCommandAsync(
new SendCommandRequest()
{
InstanceIds = new List() { instanceId },
DocumentName = "AWS-RunShellScript",
Parameters = new Dictionary>()
{
{
"commands",
new List() { "cd / && sudo python3 server.py 80" }
}
}
});
Console.WriteLine($"Restarted the web server on instance {instanceId}");
}
catch (AmazonEC2Exception ec2Exception)
{
if (ec2Exception.ErrorCode == "InvalidInstanceID.NotFound")
{
_logger.LogError(ec2Exception, $"Instance {instanceId} not found");
}
throw;
}
catch (Exception ex)
{
_logger.LogError(ex, $"An error occurred while replacing the template.: {ex.Message}");
throw;
}
}
///
/// Try to terminate an instance by its Id.
///
/// The Id of the instance to terminate.
/// Async task.
public async Task TryTerminateInstanceById(string instanceId)
{
var stopping = false;
Console.WriteLine($"Stopping {instanceId}...");
while (!stopping)
{
try
{
await _amazonAutoScaling.TerminateInstanceInAutoScalingGroupAsync(
new TerminateInstanceInAutoScalingGroupRequest()
{
InstanceId = instanceId,
ShouldDecrementDesiredCapacity = false
});
stopping = true;
}
catch (ScalingActivityInProgressException)
{
Console.WriteLine($"Scaling activity in progress for {instanceId}. Waiting...");
Thread.Sleep(10000);
}
}
}
///
/// Tries to delete the EC2 Auto Scaling group. If the group is in use or in progress,
/// waits and retries until the group is successfully deleted.
///
/// The name of the group to try to delete.
/// Async task.
public async Task TryDeleteGroupByName(string groupName)
{
var stopped = false;
while (!stopped)
{
try
{
await _amazonAutoScaling.DeleteAutoScalingGroupAsync(
new DeleteAutoScalingGroupRequest()
{
AutoScalingGroupName = groupName
});
stopped = true;
}
catch (Exception e)
when ((e is ScalingActivityInProgressException)
|| (e is Amazon.AutoScaling.Model.ResourceInUseException))
{
Console.WriteLine($"Some instances are still running. Waiting...");
Thread.Sleep(10000);
}
}
}
///
/// Terminate instances and delete the Auto Scaling group by name.
///
/// The name of the group to delete.
/// Async task.
public async Task TerminateAndDeleteAutoScalingGroupWithName(string groupName)
{
var describeGroupsResponse = await _amazonAutoScaling.DescribeAutoScalingGroupsAsync(
new DescribeAutoScalingGroupsRequest()
{
AutoScalingGroupNames = new List() { groupName }
});
if (describeGroupsResponse.AutoScalingGroups.Any())
{
// Update the size to 0.
await _amazonAutoScaling.UpdateAutoScalingGroupAsync(
new UpdateAutoScalingGroupRequest()
{
AutoScalingGroupName = groupName,
MinSize = 0
});
var group = describeGroupsResponse.AutoScalingGroups[0];
foreach (var instance in group.Instances)
{
await TryTerminateInstanceById(instance.InstanceId);
}
await TryDeleteGroupByName(groupName);
}
else
{
Console.WriteLine($"No groups found with name {groupName}.");
}
}
///
/// Get the default security group for a specified Vpc.
///
/// The Vpc to search.
/// The default security group.
public async Task GetDefaultSecurityGroupForVpc(Vpc vpc)
{
var groupResponse = await _amazonEc2.DescribeSecurityGroupsAsync(
new DescribeSecurityGroupsRequest()
{
Filters = new List()
{
new ("group-name", new List() { "default" }),
new ("vpc-id", new List() { vpc.VpcId })
}
});
return groupResponse.SecurityGroups[0];
}
///
/// Verify the default security group of a Vpc allows ingress from the calling computer.
/// This can be done by allowing ingress from this computer's IP address.
/// In some situations, such as connecting from a corporate network, you must instead specify
/// a prefix list Id. You can also temporarily open the port to any IP address while running this example.
/// If you do, be sure to remove public access when you're done.
///
/// The group to check.
/// The port to verify.
/// This computer's IP address.
/// True if the ip address is allowed on the group.
public bool VerifyInboundPortForGroup(SecurityGroup group, int port, string ipAddress)
{
var portIsOpen = false;
foreach (var ipPermission in group.IpPermissions)
{
if (ipPermission.FromPort == port)
{
foreach (var ipRange in ipPermission.Ipv4Ranges)
{
var cidr = ipRange.CidrIp;
if (cidr.StartsWith(ipAddress) || cidr == "0.0.0.0/0")
{
portIsOpen = true;
}
}
if (ipPermission.PrefixListIds.Any())
{
portIsOpen = true;
}
if (!portIsOpen)
{
Console.WriteLine("The inbound rule does not appear to be open to either this computer's IP\n" +
"address, to all IP addresses (0.0.0.0/0), or to a prefix list ID.");
}
else
{
break;
}
}
}
return portIsOpen;
}
///
/// Add an ingress rule to the specified security group that allows access on the
/// specified port from the specified IP address.
///
/// The Id of the security group to modify.
/// The port to open.
/// The IP address to allow access.
/// Async task.
public async Task OpenInboundPort(string groupId, int port, string ipAddress)
{
await _amazonEc2.AuthorizeSecurityGroupIngressAsync(
new AuthorizeSecurityGroupIngressRequest()
{
GroupId = groupId,
IpPermissions = new List()
{
new IpPermission()
{
FromPort = port,
ToPort = port,
IpProtocol = "tcp",
Ipv4Ranges = new List()
{
new IpRange() { CidrIp = $"{ipAddress}/32" }
}
}
}
});
}
///
/// Attaches an Elastic Load Balancing (ELB) target group to this EC2 Auto Scaling group.
/// The
///
/// The name of the Auto Scaling group.
/// The Arn for the target group.
/// Async task.
public async Task AttachLoadBalancerToGroup(string autoScalingGroupName, string targetGroupArn)
{
await _amazonAutoScaling.AttachLoadBalancerTargetGroupsAsync(
new AttachLoadBalancerTargetGroupsRequest()
{
AutoScalingGroupName = autoScalingGroupName,
TargetGroupARNs = new List() { targetGroupArn }
});
}
///
/// Wait until an EC2 instance is in a specified state.
///
/// The instance Id.
/// The state to wait for.
/// A Boolean value indicating the success of the action.
public async Task WaitForInstanceState(string instanceId, InstanceStateName stateName)
{
var request = new DescribeInstancesRequest
{
InstanceIds = new List { instanceId }
};
// Wait until the instance is in the specified state.
var hasState = false;
do
{
// Wait 5 seconds.
Thread.Sleep(5000);
// Check for the desired state.
var response = await _amazonEc2.DescribeInstancesAsync(request);
var instance = response.Reservations[0].Instances[0];
hasState = instance.State.Name == stateName;
Console.Write(". ");
} while (!hasState);
return hasState;
}
}
```
Create a class that wraps Elastic Load Balancing actions.
```
///
/// Encapsulates Elastic Load Balancer actions.
///
public class ElasticLoadBalancerWrapper
{
private readonly IAmazonElasticLoadBalancingV2 _amazonElasticLoadBalancingV2;
private string? _endpoint = null;
private readonly string _targetGroupName = "";
private readonly string _loadBalancerName = "";
HttpClient _httpClient = new();
public string TargetGroupName => _targetGroupName;
public string LoadBalancerName => _loadBalancerName;
///
/// Constructor for the Elastic Load Balancer wrapper.
///
/// The injected load balancing v2 client.
/// The injected configuration.
public ElasticLoadBalancerWrapper(
IAmazonElasticLoadBalancingV2 amazonElasticLoadBalancingV2,
IConfiguration configuration)
{
_amazonElasticLoadBalancingV2 = amazonElasticLoadBalancingV2;
var prefix = configuration["resourcePrefix"];
_targetGroupName = prefix + "-tg";
_loadBalancerName = prefix + "-lb";
}
///
/// Get the HTTP Endpoint of a load balancer by its name.
///
/// The name of the load balancer.
/// The HTTP endpoint.
public async Task GetEndpointForLoadBalancerByName(string loadBalancerName)
{
if (_endpoint == null)
{
var endpointResponse =
await _amazonElasticLoadBalancingV2.DescribeLoadBalancersAsync(
new DescribeLoadBalancersRequest()
{
Names = new List() { loadBalancerName }
});
_endpoint = endpointResponse.LoadBalancers[0].DNSName;
}
return _endpoint;
}
///
/// Return the GET response for an endpoint as text.
///
/// The endpoint for the request.
/// The request response.
public async Task GetEndPointResponse(string endpoint)
{
var endpointResponse = await _httpClient.GetAsync($"http://{endpoint}");
var textResponse = await endpointResponse.Content.ReadAsStringAsync();
return textResponse!;
}
///
/// Get the target health for a group by name.
///
/// The name of the group.
/// The collection of health descriptions.
public async Task> CheckTargetHealthForGroup(string groupName)
{
List result = null!;
try
{
var groupResponse =
await _amazonElasticLoadBalancingV2.DescribeTargetGroupsAsync(
new DescribeTargetGroupsRequest()
{
Names = new List() { groupName }
});
var healthResponse =
await _amazonElasticLoadBalancingV2.DescribeTargetHealthAsync(
new DescribeTargetHealthRequest()
{
TargetGroupArn = groupResponse.TargetGroups[0].TargetGroupArn
});
;
result = healthResponse.TargetHealthDescriptions;
}
catch (TargetGroupNotFoundException)
{
Console.WriteLine($"Target group {groupName} not found.");
}
return result;
}
///
/// Create an Elastic Load Balancing target group. The target group specifies how the load balancer forwards
/// requests to instances in the group and how instance health is checked.
///
/// To speed up this demo, the health check is configured with shortened times and lower thresholds. In production,
/// you might want to decrease the sensitivity of your health checks to avoid unwanted failures.
///
/// The name for the group.
/// The protocol, such as HTTP.
/// The port to use to forward requests, such as 80.
/// The Id of the Vpc in which the load balancer exists.
/// The new TargetGroup object.
public async Task CreateTargetGroupOnVpc(string groupName, ProtocolEnum protocol, int port, string vpcId)
{
var createResponse = await _amazonElasticLoadBalancingV2.CreateTargetGroupAsync(
new CreateTargetGroupRequest()
{
Name = groupName,
Protocol = protocol,
Port = port,
HealthCheckPath = "/healthcheck",
HealthCheckIntervalSeconds = 10,
HealthCheckTimeoutSeconds = 5,
HealthyThresholdCount = 2,
UnhealthyThresholdCount = 2,
VpcId = vpcId
});
var targetGroup = createResponse.TargetGroups[0];
return targetGroup;
}
///
/// Create an Elastic Load Balancing load balancer that uses the specified subnets
/// and forwards requests to the specified target group.
///
/// The name for the new load balancer.
/// Subnets for the load balancer.
/// Target group for forwarded requests.
/// The new LoadBalancer object.
public async Task CreateLoadBalancerAndListener(string name, List subnetIds, TargetGroup targetGroup)
{
var createLbResponse = await _amazonElasticLoadBalancingV2.CreateLoadBalancerAsync(
new CreateLoadBalancerRequest()
{
Name = name,
Subnets = subnetIds
});
var loadBalancerArn = createLbResponse.LoadBalancers[0].LoadBalancerArn;
// Wait for load balancer to be available.
var loadBalancerReady = false;
while (!loadBalancerReady)
{
try
{
var describeResponse =
await _amazonElasticLoadBalancingV2.DescribeLoadBalancersAsync(
new DescribeLoadBalancersRequest()
{
Names = new List() { name }
});
var loadBalancerState = describeResponse.LoadBalancers[0].State.Code;
loadBalancerReady = loadBalancerState == LoadBalancerStateEnum.Active;
}
catch (LoadBalancerNotFoundException)
{
loadBalancerReady = false;
}
Thread.Sleep(10000);
}
// Create the listener.
await _amazonElasticLoadBalancingV2.CreateListenerAsync(
new CreateListenerRequest()
{
LoadBalancerArn = loadBalancerArn,
Protocol = targetGroup.Protocol,
Port = targetGroup.Port,
DefaultActions = new List()
{
new Action()
{
Type = ActionTypeEnum.Forward,
TargetGroupArn = targetGroup.TargetGroupArn
}
}
});
return createLbResponse.LoadBalancers[0];
}
///
/// Verify this computer can successfully send a GET request to the
/// load balancer endpoint.
///
/// The endpoint to check.
/// True if successful.
public async Task VerifyLoadBalancerEndpoint(string endpoint)
{
var success = false;
var retries = 3;
while (!success && retries > 0)
{
try
{
var endpointResponse = await _httpClient.GetAsync($"http://{endpoint}");
Console.WriteLine($"Response: {endpointResponse.StatusCode}.");
if (endpointResponse.IsSuccessStatusCode)
{
success = true;
}
else
{
retries = 0;
}
}
catch (HttpRequestException)
{
Console.WriteLine("Connection error, retrying...");
retries--;
Thread.Sleep(10000);
}
}
return success;
}
///
/// Delete a load balancer by its specified name.
///
/// The name of the load balancer to delete.
/// Async task.
public async Task DeleteLoadBalancerByName(string name)
{
try
{
var describeLoadBalancerResponse =
await _amazonElasticLoadBalancingV2.DescribeLoadBalancersAsync(
new DescribeLoadBalancersRequest()
{
Names = new List() { name }
});
var lbArn = describeLoadBalancerResponse.LoadBalancers[0].LoadBalancerArn;
await _amazonElasticLoadBalancingV2.DeleteLoadBalancerAsync(
new DeleteLoadBalancerRequest()
{
LoadBalancerArn = lbArn
}
);
}
catch (LoadBalancerNotFoundException)
{
Console.WriteLine($"Load balancer {name} not found.");
}
}
///
/// Delete a TargetGroup by its specified name.
///
/// Name of the group to delete.
/// Async task.
public async Task DeleteTargetGroupByName(string groupName)
{
var done = false;
while (!done)
{
try
{
var groupResponse =
await _amazonElasticLoadBalancingV2.DescribeTargetGroupsAsync(
new DescribeTargetGroupsRequest()
{
Names = new List() { groupName }
});
var targetArn = groupResponse.TargetGroups[0].TargetGroupArn;
await _amazonElasticLoadBalancingV2.DeleteTargetGroupAsync(
new DeleteTargetGroupRequest() { TargetGroupArn = targetArn });
Console.WriteLine($"Deleted load balancing target group {groupName}.");
done = true;
}
catch (TargetGroupNotFoundException)
{
Console.WriteLine(
$"Target group {groupName} not found, could not delete.");
done = true;
}
catch (ResourceInUseException)
{
Console.WriteLine("Target group not yet released, waiting...");
Thread.Sleep(10000);
}
}
}
}
```
Create a class that uses DynamoDB to simulate a recommendation service.
```
///
/// Encapsulates a DynamoDB table to use as a service that recommends books, movies, and songs.
///
public class Recommendations
{
private readonly IAmazonDynamoDB _amazonDynamoDb;
private readonly DynamoDBContext _context;
private readonly string _tableName;
public string TableName => _tableName;
///
/// Constructor for the Recommendations service.
///
/// The injected DynamoDb client.
/// The injected configuration.
public Recommendations(IAmazonDynamoDB amazonDynamoDb, IConfiguration configuration)
{
_amazonDynamoDb = amazonDynamoDb;
_context = new DynamoDBContext(_amazonDynamoDb);
_tableName = configuration["databaseName"]!;
}
///
/// Create the DynamoDb table with a specified name.
///
/// The name for the table.
/// True when ready.
public async Task CreateDatabaseWithName(string tableName)
{
try
{
Console.Write($"Creating table {tableName}...");
var createRequest = new CreateTableRequest()
{
TableName = tableName,
AttributeDefinitions = new List()
{
new AttributeDefinition()
{
AttributeName = "MediaType",
AttributeType = ScalarAttributeType.S
},
new AttributeDefinition()
{
AttributeName = "ItemId",
AttributeType = ScalarAttributeType.N
}
},
KeySchema = new List()
{
new KeySchemaElement()
{
AttributeName = "MediaType",
KeyType = KeyType.HASH
},
new KeySchemaElement()
{
AttributeName = "ItemId",
KeyType = KeyType.RANGE
}
},
ProvisionedThroughput = new ProvisionedThroughput()
{
ReadCapacityUnits = 5,
WriteCapacityUnits = 5
}
};
await _amazonDynamoDb.CreateTableAsync(createRequest);
// Wait until the table is ACTIVE and then report success.
Console.Write("\nWaiting for table to become active...");
var request = new DescribeTableRequest
{
TableName = tableName
};
TableStatus status;
do
{
Thread.Sleep(2000);
var describeTableResponse = await _amazonDynamoDb.DescribeTableAsync(request);
status = describeTableResponse.Table.TableStatus;
Console.Write(".");
}
while (status != "ACTIVE");
return status == TableStatus.ACTIVE;
}
catch (ResourceInUseException)
{
Console.WriteLine($"Table {tableName} already exists.");
return false;
}
}
///
/// Populate the database table with data from a specified path.
///
/// The name of the table.
/// The path of the recommendations data.
/// Async task.
public async Task PopulateDatabase(string databaseTableName, string recommendationsPath)
{
var recommendationsText = await File.ReadAllTextAsync(recommendationsPath);
var records =
JsonSerializer.Deserialize(recommendationsText);
var batchWrite = _context.CreateBatchWrite();
foreach (var record in records!)
{
batchWrite.AddPutItem(record);
}
await batchWrite.ExecuteAsync();
}
///
/// Delete the recommendation table by name.
///
/// The name of the recommendation table.
/// Async task.
public async Task DestroyDatabaseByName(string tableName)
{
try
{
await _amazonDynamoDb.DeleteTableAsync(
new DeleteTableRequest() { TableName = tableName });
Console.WriteLine($"Table {tableName} was deleted.");
}
catch (ResourceNotFoundException)
{
Console.WriteLine($"Table {tableName} not found");
}
}
}
```
Create a class that wraps Systems Manager actions.
```
///
/// Encapsulates Systems Manager parameter operations. This example uses these parameters
/// to drive the demonstration of resilient architecture, such as failure of a dependency or
/// how the service responds to a health check.
///
public class SmParameterWrapper
{
private readonly IAmazonSimpleSystemsManagement _amazonSimpleSystemsManagement;
private readonly string _tableParameter = "doc-example-resilient-architecture-table";
private readonly string _failureResponseParameter = "doc-example-resilient-architecture-failure-response";
private readonly string _healthCheckParameter = "doc-example-resilient-architecture-health-check";
private readonly string _tableName = "";
public string TableParameter => _tableParameter;
public string TableName => _tableName;
public string HealthCheckParameter => _healthCheckParameter;
public string FailureResponseParameter => _failureResponseParameter;
///
/// Constructor for the SmParameterWrapper.
///
/// The injected Simple Systems Management client.
/// The injected configuration.
public SmParameterWrapper(IAmazonSimpleSystemsManagement amazonSimpleSystemsManagement, IConfiguration configuration)
{
_amazonSimpleSystemsManagement = amazonSimpleSystemsManagement;
_tableName = configuration["databaseName"]!;
}
///
/// Reset the Systems Manager parameters to starting values for the demo.
///
/// Async task.
public async Task Reset()
{
await this.PutParameterByName(_tableParameter, _tableName);
await this.PutParameterByName(_failureResponseParameter, "none");
await this.PutParameterByName(_healthCheckParameter, "shallow");
}
///
/// Set the value of a named Systems Manager parameter.
///
/// The name of the parameter.
/// The value to set.
/// Async task.
public async Task PutParameterByName(string name, string value)
{
await _amazonSimpleSystemsManagement.PutParameterAsync(
new PutParameterRequest() { Name = name, Value = value, Overwrite = true });
}
}
```
+ For API details, see the following topics in *AWS SDK for .NET API Reference*.
+ [AttachLoadBalancerTargetGroups](https://docs.aws.amazon.com/goto/DotNetSDKV3/autoscaling-2011-01-01/AttachLoadBalancerTargetGroups)
+ [CreateAutoScalingGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/autoscaling-2011-01-01/CreateAutoScalingGroup)
+ [CreateInstanceProfile](https://docs.aws.amazon.com/goto/DotNetSDKV3/iam-2010-05-08/CreateInstanceProfile)
+ [CreateLaunchTemplate](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/CreateLaunchTemplate)
+ [CreateListener](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/CreateListener)
+ [CreateLoadBalancer](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/CreateLoadBalancer)
+ [CreateTargetGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/CreateTargetGroup)
+ [DeleteAutoScalingGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/autoscaling-2011-01-01/DeleteAutoScalingGroup)
+ [DeleteInstanceProfile](https://docs.aws.amazon.com/goto/DotNetSDKV3/iam-2010-05-08/DeleteInstanceProfile)
+ [DeleteLaunchTemplate](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/DeleteLaunchTemplate)
+ [DeleteLoadBalancer](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DeleteLoadBalancer)
+ [DeleteTargetGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DeleteTargetGroup)
+ [DescribeAutoScalingGroups](https://docs.aws.amazon.com/goto/DotNetSDKV3/autoscaling-2011-01-01/DescribeAutoScalingGroups)
+ [DescribeAvailabilityZones](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/DescribeAvailabilityZones)
+ [DescribeIamInstanceProfileAssociations](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/DescribeIamInstanceProfileAssociations)
+ [DescribeInstances](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/DescribeInstances)
+ [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers)
+ [DescribeSubnets](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/DescribeSubnets)
+ [DescribeTargetGroups](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DescribeTargetGroups)
+ [DescribeTargetHealth](https://docs.aws.amazon.com/goto/DotNetSDKV3/elasticloadbalancingv2-2015-12-01/DescribeTargetHealth)
+ [DescribeVpcs](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/DescribeVpcs)
+ [RebootInstances](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/RebootInstances)
+ [ReplaceIamInstanceProfileAssociation](https://docs.aws.amazon.com/goto/DotNetSDKV3/ec2-2016-11-15/ReplaceIamInstanceProfileAssociation)
+ [TerminateInstanceInAutoScalingGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/autoscaling-2011-01-01/TerminateInstanceInAutoScalingGroup)
+ [UpdateAutoScalingGroup](https://docs.aws.amazon.com/goto/DotNetSDKV3/autoscaling-2011-01-01/UpdateAutoScalingGroup)
------
#### [ Java ]
**SDK for Java 2.x**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/resilient_service#code-examples).
Run the interactive scenario at a command prompt.
```
public class Main {
public static final String fileName = "C:\\AWS\\resworkflow\\recommendations.json"; // Modify file location.
public static final String tableName = "doc-example-recommendation-service";
public static final String startScript = "C:\\AWS\\resworkflow\\server_startup_script.sh"; // Modify file location.
public static final String policyFile = "C:\\AWS\\resworkflow\\instance_policy.json"; // Modify file location.
public static final String ssmJSON = "C:\\AWS\\resworkflow\\ssm_only_policy.json"; // Modify file location.
public static final String failureResponse = "doc-example-resilient-architecture-failure-response";
public static final String healthCheck = "doc-example-resilient-architecture-health-check";
public static final String templateName = "doc-example-resilience-template";
public static final String roleName = "doc-example-resilience-role";
public static final String policyName = "doc-example-resilience-pol";
public static final String profileName = "doc-example-resilience-prof";
public static final String badCredsProfileName = "doc-example-resilience-prof-bc";
public static final String targetGroupName = "doc-example-resilience-tg";
public static final String autoScalingGroupName = "doc-example-resilience-group";
public static final String lbName = "doc-example-resilience-lb";
public static final String protocol = "HTTP";
public static final int port = 80;
public static final String DASHES = new String(new char[80]).replace("\0", "-");
public static void main(String[] args) throws IOException, InterruptedException {
Scanner in = new Scanner(System.in);
Database database = new Database();
AutoScaler autoScaler = new AutoScaler();
LoadBalancer loadBalancer = new LoadBalancer();
System.out.println(DASHES);
System.out.println("Welcome to the demonstration of How to Build and Manage a Resilient Service!");
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("A - SETUP THE RESOURCES");
System.out.println("Press Enter when you're ready to start deploying resources.");
in.nextLine();
deploy(loadBalancer);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("B - DEMO THE RESILIENCE FUNCTIONALITY");
System.out.println("Press Enter when you're ready.");
in.nextLine();
demo(loadBalancer);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("C - DELETE THE RESOURCES");
System.out.println("""
This concludes the demo of how to build and manage a resilient service.
To keep things tidy and to avoid unwanted charges on your account, we can clean up all AWS resources
that were created for this demo.
""");
System.out.println("\n Do you want to delete the resources (y/n)? ");
String userInput = in.nextLine().trim().toLowerCase(); // Capture user input
if (userInput.equals("y")) {
// Delete resources here
deleteResources(loadBalancer, autoScaler, database);
System.out.println("Resources deleted.");
} else {
System.out.println("""
Okay, we'll leave the resources intact.
Don't forget to delete them when you're done with them or you might incur unexpected charges.
""");
}
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("The example has completed. ");
System.out.println("\n Thanks for watching!");
System.out.println(DASHES);
}
// Deletes the AWS resources used in this example.
private static void deleteResources(LoadBalancer loadBalancer, AutoScaler autoScaler, Database database)
throws IOException, InterruptedException {
loadBalancer.deleteLoadBalancer(lbName);
System.out.println("*** Wait 30 secs for resource to be deleted");
TimeUnit.SECONDS.sleep(30);
loadBalancer.deleteTargetGroup(targetGroupName);
autoScaler.deleteAutoScaleGroup(autoScalingGroupName);
autoScaler.deleteRolesPolicies(policyName, roleName, profileName);
autoScaler.deleteTemplate(templateName);
database.deleteTable(tableName);
}
private static void deploy(LoadBalancer loadBalancer) throws InterruptedException, IOException {
Scanner in = new Scanner(System.in);
System.out.println(
"""
For this demo, we'll use the AWS SDK for Java (v2) to create several AWS resources
to set up a load-balanced web service endpoint and explore some ways to make it resilient
against various kinds of failures.
Some of the resources create by this demo are:
\t* A DynamoDB table that the web service depends on to provide book, movie, and song recommendations.
\t* An EC2 launch template that defines EC2 instances that each contain a Python web server.
\t* An EC2 Auto Scaling group that manages EC2 instances across several Availability Zones.
\t* An Elastic Load Balancing (ELB) load balancer that targets the Auto Scaling group to distribute requests.
""");
System.out.println("Press Enter when you're ready.");
in.nextLine();
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("Creating and populating a DynamoDB table named " + tableName);
Database database = new Database();
database.createTable(tableName, fileName);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("""
Creating an EC2 launch template that runs '{startup_script}' when an instance starts.
This script starts a Python web server defined in the `server.py` script. The web server
listens to HTTP requests on port 80 and responds to requests to '/' and to '/healthcheck'.
For demo purposes, this server is run as the root user. In production, the best practice is to
run a web server, such as Apache, with least-privileged credentials.
The template also defines an IAM policy that each instance uses to assume a role that grants
permissions to access the DynamoDB recommendation table and Systems Manager parameters
that control the flow of the demo.
""");
LaunchTemplateCreator templateCreator = new LaunchTemplateCreator();
templateCreator.createTemplate(policyFile, policyName, profileName, startScript, templateName, roleName);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println(
"Creating an EC2 Auto Scaling group that maintains three EC2 instances, each in a different Availability Zone.");
System.out.println("*** Wait 30 secs for the VPC to be created");
TimeUnit.SECONDS.sleep(30);
AutoScaler autoScaler = new AutoScaler();
String[] zones = autoScaler.createGroup(3, templateName, autoScalingGroupName);
System.out.println("""
At this point, you have EC2 instances created. Once each instance starts, it listens for
HTTP requests. You can see these instances in the console or continue with the demo.
Press Enter when you're ready to continue.
""");
in.nextLine();
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("Creating variables that control the flow of the demo.");
ParameterHelper paramHelper = new ParameterHelper();
paramHelper.reset();
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("""
Creating an Elastic Load Balancing target group and load balancer. The target group
defines how the load balancer connects to instances. The load balancer provides a
single endpoint where clients connect and dispatches requests to instances in the group.
""");
String vpcId = autoScaler.getDefaultVPC();
List subnets = autoScaler.getSubnets(vpcId, zones);
System.out.println("You have retrieved a list with " + subnets.size() + " subnets");
String targetGroupArn = loadBalancer.createTargetGroup(protocol, port, vpcId, targetGroupName);
String elbDnsName = loadBalancer.createLoadBalancer(subnets, targetGroupArn, lbName, port, protocol);
autoScaler.attachLoadBalancerTargetGroup(autoScalingGroupName, targetGroupArn);
System.out.println("Verifying access to the load balancer endpoint...");
boolean wasSuccessul = loadBalancer.verifyLoadBalancerEndpoint(elbDnsName);
if (!wasSuccessul) {
System.out.println("Couldn't connect to the load balancer, verifying that the port is open...");
CloseableHttpClient httpClient = HttpClients.createDefault();
// Create an HTTP GET request to "http://checkip.amazonaws.com"
HttpGet httpGet = new HttpGet("http://checkip.amazonaws.com");
try {
// Execute the request and get the response
HttpResponse response = httpClient.execute(httpGet);
// Read the response content.
String ipAddress = IOUtils.toString(response.getEntity().getContent(), StandardCharsets.UTF_8).trim();
// Print the public IP address.
System.out.println("Public IP Address: " + ipAddress);
GroupInfo groupInfo = autoScaler.verifyInboundPort(vpcId, port, ipAddress);
if (!groupInfo.isPortOpen()) {
System.out.println("""
For this example to work, the default security group for your default VPC must
allow access from this computer. You can either add it automatically from this
example or add it yourself using the AWS Management Console.
""");
System.out.println(
"Do you want to add a rule to security group " + groupInfo.getGroupName() + " to allow");
System.out.println("inbound traffic on port " + port + " from your computer's IP address (y/n) ");
String ans = in.nextLine();
if ("y".equalsIgnoreCase(ans)) {
autoScaler.openInboundPort(groupInfo.getGroupName(), String.valueOf(port), ipAddress);
System.out.println("Security group rule added.");
} else {
System.out.println("No security group rule added.");
}
}
} catch (AutoScalingException e) {
e.printStackTrace();
}
} else if (wasSuccessul) {
System.out.println("Your load balancer is ready. You can access it by browsing to:");
System.out.println("\t http://" + elbDnsName);
} else {
System.out.println("Couldn't get a successful response from the load balancer endpoint. Troubleshoot by");
System.out.println("manually verifying that your VPC and security group are configured correctly and that");
System.out.println("you can successfully make a GET request to the load balancer.");
}
System.out.println("Press Enter when you're ready to continue with the demo.");
in.nextLine();
}
// A method that controls the demo part of the Java program.
public static void demo(LoadBalancer loadBalancer) throws IOException, InterruptedException {
ParameterHelper paramHelper = new ParameterHelper();
System.out.println("Read the ssm_only_policy.json file");
String ssmOnlyPolicy = readFileAsString(ssmJSON);
System.out.println("Resetting parameters to starting values for demo.");
paramHelper.reset();
System.out.println(
"""
This part of the demonstration shows how to toggle different parts of the system
to create situations where the web service fails, and shows how using a resilient
architecture can keep the web service running in spite of these failures.
At the start, the load balancer endpoint returns recommendations and reports that all targets are healthy.
""");
demoChoices(loadBalancer);
System.out.println(
"""
The web service running on the EC2 instances gets recommendations by querying a DynamoDB table.
The table name is contained in a Systems Manager parameter named self.param_helper.table.
To simulate a failure of the recommendation service, let's set this parameter to name a non-existent table.
""");
paramHelper.put(paramHelper.tableName, "this-is-not-a-table");
System.out.println(
"""
\nNow, sending a GET request to the load balancer endpoint returns a failure code. But, the service reports as
healthy to the load balancer because shallow health checks don't check for failure of the recommendation service.
""");
demoChoices(loadBalancer);
System.out.println(
"""
Instead of failing when the recommendation service fails, the web service can return a static response.
While this is not a perfect solution, it presents the customer with a somewhat better experience than failure.
""");
paramHelper.put(paramHelper.failureResponse, "static");
System.out.println("""
Now, sending a GET request to the load balancer endpoint returns a static response.
The service still reports as healthy because health checks are still shallow.
""");
demoChoices(loadBalancer);
System.out.println("Let's reinstate the recommendation service.");
paramHelper.put(paramHelper.tableName, paramHelper.dyntable);
System.out.println("""
Let's also substitute bad credentials for one of the instances in the target group so that it can't
access the DynamoDB recommendation table. We will get an instance id value.
""");
LaunchTemplateCreator templateCreator = new LaunchTemplateCreator();
AutoScaler autoScaler = new AutoScaler();
// Create a new instance profile based on badCredsProfileName.
templateCreator.createInstanceProfile(policyFile, policyName, badCredsProfileName, roleName);
String badInstanceId = autoScaler.getBadInstance(autoScalingGroupName);
System.out.println("The bad instance id values used for this demo is " + badInstanceId);
String profileAssociationId = autoScaler.getInstanceProfile(badInstanceId);
System.out.println("The association Id value is " + profileAssociationId);
System.out.println("Replacing the profile for instance " + badInstanceId
+ " with a profile that contains bad credentials");
autoScaler.replaceInstanceProfile(badInstanceId, badCredsProfileName, profileAssociationId);
System.out.println(
"""
Now, sending a GET request to the load balancer endpoint returns either a recommendation or a static response,
depending on which instance is selected by the load balancer.
""");
demoChoices(loadBalancer);
System.out.println("""
Let's implement a deep health check. For this demo, a deep health check tests whether
the web service can access the DynamoDB table that it depends on for recommendations. Note that
the deep health check is only for ELB routing and not for Auto Scaling instance health.
This kind of deep health check is not recommended for Auto Scaling instance health, because it
risks accidental termination of all instances in the Auto Scaling group when a dependent service fails.
""");
System.out.println("""
By implementing deep health checks, the load balancer can detect when one of the instances is failing
and take that instance out of rotation.
""");
paramHelper.put(paramHelper.healthCheck, "deep");
System.out.println("""
Now, checking target health indicates that the instance with bad credentials
is unhealthy. Note that it might take a minute or two for the load balancer to detect the unhealthy
instance. Sending a GET request to the load balancer endpoint always returns a recommendation, because
the load balancer takes unhealthy instances out of its rotation.
""");
demoChoices(loadBalancer);
System.out.println(
"""
Because the instances in this demo are controlled by an auto scaler, the simplest way to fix an unhealthy
instance is to terminate it and let the auto scaler start a new instance to replace it.
""");
autoScaler.terminateInstance(badInstanceId);
System.out.println("""
Even while the instance is terminating and the new instance is starting, sending a GET
request to the web service continues to get a successful recommendation response because
the load balancer routes requests to the healthy instances. After the replacement instance
starts and reports as healthy, it is included in the load balancing rotation.
Note that terminating and replacing an instance typically takes several minutes, during which time you
can see the changing health check status until the new instance is running and healthy.
""");
demoChoices(loadBalancer);
System.out.println(
"If the recommendation service fails now, deep health checks mean all instances report as unhealthy.");
paramHelper.put(paramHelper.tableName, "this-is-not-a-table");
demoChoices(loadBalancer);
paramHelper.reset();
}
public static void demoChoices(LoadBalancer loadBalancer) throws IOException, InterruptedException {
String[] actions = {
"Send a GET request to the load balancer endpoint.",
"Check the health of load balancer targets.",
"Go to the next part of the demo."
};
Scanner scanner = new Scanner(System.in);
while (true) {
System.out.println("-".repeat(88));
System.out.println("See the current state of the service by selecting one of the following choices:");
for (int i = 0; i < actions.length; i++) {
System.out.println(i + ": " + actions[i]);
}
try {
System.out.print("\nWhich action would you like to take? ");
int choice = scanner.nextInt();
System.out.println("-".repeat(88));
switch (choice) {
case 0 -> {
System.out.println("Request:\n");
System.out.println("GET http://" + loadBalancer.getEndpoint(lbName));
CloseableHttpClient httpClient = HttpClients.createDefault();
// Create an HTTP GET request to the ELB.
HttpGet httpGet = new HttpGet("http://" + loadBalancer.getEndpoint(lbName));
// Execute the request and get the response.
HttpResponse response = httpClient.execute(httpGet);
int statusCode = response.getStatusLine().getStatusCode();
System.out.println("HTTP Status Code: " + statusCode);
// Display the JSON response
BufferedReader reader = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
StringBuilder jsonResponse = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
jsonResponse.append(line);
}
reader.close();
// Print the formatted JSON response.
System.out.println("Full Response:\n");
System.out.println(jsonResponse.toString());
// Close the HTTP client.
httpClient.close();
}
case 1 -> {
System.out.println("\nChecking the health of load balancer targets:\n");
List health = loadBalancer.checkTargetHealth(targetGroupName);
for (TargetHealthDescription target : health) {
System.out.printf("\tTarget %s on port %d is %s%n", target.target().id(),
target.target().port(), target.targetHealth().stateAsString());
}
System.out.println("""
Note that it can take a minute or two for the health check to update
after changes are made.
""");
}
case 2 -> {
System.out.println("\nOkay, let's move on.");
System.out.println("-".repeat(88));
return; // Exit the method when choice is 2
}
default -> System.out.println("You must choose a value between 0-2. Please select again.");
}
} catch (java.util.InputMismatchException e) {
System.out.println("Invalid input. Please select again.");
scanner.nextLine(); // Clear the input buffer.
}
}
}
public static String readFileAsString(String filePath) throws IOException {
byte[] bytes = Files.readAllBytes(Paths.get(filePath));
return new String(bytes);
}
}
```
Create a class that wraps Auto Scaling and Amazon EC2 actions.
```
public class AutoScaler {
private static Ec2Client ec2Client;
private static AutoScalingClient autoScalingClient;
private static IamClient iamClient;
private static SsmClient ssmClient;
private IamClient getIAMClient() {
if (iamClient == null) {
iamClient = IamClient.builder()
.region(Region.US_EAST_1)
.build();
}
return iamClient;
}
private SsmClient getSSMClient() {
if (ssmClient == null) {
ssmClient = SsmClient.builder()
.region(Region.US_EAST_1)
.build();
}
return ssmClient;
}
private Ec2Client getEc2Client() {
if (ec2Client == null) {
ec2Client = Ec2Client.builder()
.region(Region.US_EAST_1)
.build();
}
return ec2Client;
}
private AutoScalingClient getAutoScalingClient() {
if (autoScalingClient == null) {
autoScalingClient = AutoScalingClient.builder()
.region(Region.US_EAST_1)
.build();
}
return autoScalingClient;
}
/**
* Terminates and instances in an EC2 Auto Scaling group. After an instance is
* terminated, it can no longer be accessed.
*/
public void terminateInstance(String instanceId) {
TerminateInstanceInAutoScalingGroupRequest terminateInstanceIRequest = TerminateInstanceInAutoScalingGroupRequest
.builder()
.instanceId(instanceId)
.shouldDecrementDesiredCapacity(false)
.build();
getAutoScalingClient().terminateInstanceInAutoScalingGroup(terminateInstanceIRequest);
System.out.format("Terminated instance %s.", instanceId);
}
/**
* Replaces the profile associated with a running instance. After the profile is
* replaced, the instance is rebooted to ensure that it uses the new profile.
* When
* the instance is ready, Systems Manager is used to restart the Python web
* server.
*/
public void replaceInstanceProfile(String instanceId, String newInstanceProfileName, String profileAssociationId)
throws InterruptedException {
// Create an IAM instance profile specification.
software.amazon.awssdk.services.ec2.model.IamInstanceProfileSpecification iamInstanceProfile = software.amazon.awssdk.services.ec2.model.IamInstanceProfileSpecification
.builder()
.name(newInstanceProfileName) // Make sure 'newInstanceProfileName' is a valid IAM Instance Profile
// name.
.build();
// Replace the IAM instance profile association for the EC2 instance.
ReplaceIamInstanceProfileAssociationRequest replaceRequest = ReplaceIamInstanceProfileAssociationRequest
.builder()
.iamInstanceProfile(iamInstanceProfile)
.associationId(profileAssociationId) // Make sure 'profileAssociationId' is a valid association ID.
.build();
try {
getEc2Client().replaceIamInstanceProfileAssociation(replaceRequest);
// Handle the response as needed.
} catch (Ec2Exception e) {
// Handle exceptions, log, or report the error.
System.err.println("Error: " + e.getMessage());
}
System.out.format("Replaced instance profile for association %s with profile %s.", profileAssociationId,
newInstanceProfileName);
TimeUnit.SECONDS.sleep(15);
boolean instReady = false;
int tries = 0;
// Reboot after 60 seconds
while (!instReady) {
if (tries % 6 == 0) {
getEc2Client().rebootInstances(RebootInstancesRequest.builder()
.instanceIds(instanceId)
.build());
System.out.println("Rebooting instance " + instanceId + " and waiting for it to be ready.");
}
tries++;
try {
TimeUnit.SECONDS.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
DescribeInstanceInformationResponse informationResponse = getSSMClient().describeInstanceInformation();
List instanceInformationList = informationResponse.instanceInformationList();
for (InstanceInformation info : instanceInformationList) {
if (info.instanceId().equals(instanceId)) {
instReady = true;
break;
}
}
}
SendCommandRequest sendCommandRequest = SendCommandRequest.builder()
.instanceIds(instanceId)
.documentName("AWS-RunShellScript")
.parameters(Collections.singletonMap("commands",
Collections.singletonList("cd / && sudo python3 server.py 80")))
.build();
getSSMClient().sendCommand(sendCommandRequest);
System.out.println("Restarted the Python web server on instance " + instanceId + ".");
}
public void openInboundPort(String secGroupId, String port, String ipAddress) {
AuthorizeSecurityGroupIngressRequest ingressRequest = AuthorizeSecurityGroupIngressRequest.builder()
.groupName(secGroupId)
.cidrIp(ipAddress)
.fromPort(Integer.parseInt(port))
.build();
getEc2Client().authorizeSecurityGroupIngress(ingressRequest);
System.out.format("Authorized ingress to %s on port %s from %s.", secGroupId, port, ipAddress);
}
/**
* Detaches a role from an instance profile, detaches policies from the role,
* and deletes all the resources.
*/
public void deleteInstanceProfile(String roleName, String profileName) {
try {
software.amazon.awssdk.services.iam.model.GetInstanceProfileRequest getInstanceProfileRequest = software.amazon.awssdk.services.iam.model.GetInstanceProfileRequest
.builder()
.instanceProfileName(profileName)
.build();
GetInstanceProfileResponse response = getIAMClient().getInstanceProfile(getInstanceProfileRequest);
String name = response.instanceProfile().instanceProfileName();
System.out.println(name);
RemoveRoleFromInstanceProfileRequest profileRequest = RemoveRoleFromInstanceProfileRequest.builder()
.instanceProfileName(profileName)
.roleName(roleName)
.build();
getIAMClient().removeRoleFromInstanceProfile(profileRequest);
DeleteInstanceProfileRequest deleteInstanceProfileRequest = DeleteInstanceProfileRequest.builder()
.instanceProfileName(profileName)
.build();
getIAMClient().deleteInstanceProfile(deleteInstanceProfileRequest);
System.out.println("Deleted instance profile " + profileName);
DeleteRoleRequest deleteRoleRequest = DeleteRoleRequest.builder()
.roleName(roleName)
.build();
// List attached role policies.
ListAttachedRolePoliciesResponse rolesResponse = getIAMClient()
.listAttachedRolePolicies(role -> role.roleName(roleName));
List attachedPolicies = rolesResponse.attachedPolicies();
for (AttachedPolicy attachedPolicy : attachedPolicies) {
DetachRolePolicyRequest request = DetachRolePolicyRequest.builder()
.roleName(roleName)
.policyArn(attachedPolicy.policyArn())
.build();
getIAMClient().detachRolePolicy(request);
System.out.println("Detached and deleted policy " + attachedPolicy.policyName());
}
getIAMClient().deleteRole(deleteRoleRequest);
System.out.println("Instance profile and role deleted.");
} catch (IamException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
public void deleteTemplate(String templateName) {
getEc2Client().deleteLaunchTemplate(name -> name.launchTemplateName(templateName));
System.out.format(templateName + " was deleted.");
}
public void deleteAutoScaleGroup(String groupName) {
DeleteAutoScalingGroupRequest deleteAutoScalingGroupRequest = DeleteAutoScalingGroupRequest.builder()
.autoScalingGroupName(groupName)
.forceDelete(true)
.build();
getAutoScalingClient().deleteAutoScalingGroup(deleteAutoScalingGroupRequest);
System.out.println(groupName + " was deleted.");
}
/*
* Verify the default security group of the specified VPC allows ingress from
* this
* computer. This can be done by allowing ingress from this computer's IP
* address. In some situations, such as connecting from a corporate network, you
* must instead specify a prefix list ID. You can also temporarily open the port
* to
* any IP address while running this example. If you do, be sure to remove
* public
* access when you're done.
*
*/
public GroupInfo verifyInboundPort(String VPC, int port, String ipAddress) {
boolean portIsOpen = false;
GroupInfo groupInfo = new GroupInfo();
try {
Filter filter = Filter.builder()
.name("group-name")
.values("default")
.build();
Filter filter1 = Filter.builder()
.name("vpc-id")
.values(VPC)
.build();
DescribeSecurityGroupsRequest securityGroupsRequest = DescribeSecurityGroupsRequest.builder()
.filters(filter, filter1)
.build();
DescribeSecurityGroupsResponse securityGroupsResponse = getEc2Client()
.describeSecurityGroups(securityGroupsRequest);
String securityGroup = securityGroupsResponse.securityGroups().get(0).groupName();
groupInfo.setGroupName(securityGroup);
for (SecurityGroup secGroup : securityGroupsResponse.securityGroups()) {
System.out.println("Found security group: " + secGroup.groupId());
for (IpPermission ipPermission : secGroup.ipPermissions()) {
if (ipPermission.fromPort() == port) {
System.out.println("Found inbound rule: " + ipPermission);
for (IpRange ipRange : ipPermission.ipRanges()) {
String cidrIp = ipRange.cidrIp();
if (cidrIp.startsWith(ipAddress) || cidrIp.equals("0.0.0.0/0")) {
System.out.println(cidrIp + " is applicable");
portIsOpen = true;
}
}
if (!ipPermission.prefixListIds().isEmpty()) {
System.out.println("Prefix lList is applicable");
portIsOpen = true;
}
if (!portIsOpen) {
System.out
.println("The inbound rule does not appear to be open to either this computer's IP,"
+ " all IP addresses (0.0.0.0/0), or to a prefix list ID.");
} else {
break;
}
}
}
}
} catch (AutoScalingException e) {
System.err.println(e.awsErrorDetails().errorMessage());
}
groupInfo.setPortOpen(portIsOpen);
return groupInfo;
}
/*
* Attaches an Elastic Load Balancing (ELB) target group to this EC2 Auto
* Scaling group.
* The target group specifies how the load balancer forward requests to the
* instances
* in the group.
*/
public void attachLoadBalancerTargetGroup(String asGroupName, String targetGroupARN) {
try {
AttachLoadBalancerTargetGroupsRequest targetGroupsRequest = AttachLoadBalancerTargetGroupsRequest.builder()
.autoScalingGroupName(asGroupName)
.targetGroupARNs(targetGroupARN)
.build();
getAutoScalingClient().attachLoadBalancerTargetGroups(targetGroupsRequest);
System.out.println("Attached load balancer to " + asGroupName);
} catch (AutoScalingException e) {
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
}
}
// Creates an EC2 Auto Scaling group with the specified size.
public String[] createGroup(int groupSize, String templateName, String autoScalingGroupName) {
// Get availability zones.
software.amazon.awssdk.services.ec2.model.DescribeAvailabilityZonesRequest zonesRequest = software.amazon.awssdk.services.ec2.model.DescribeAvailabilityZonesRequest
.builder()
.build();
DescribeAvailabilityZonesResponse zonesResponse = getEc2Client().describeAvailabilityZones(zonesRequest);
List availabilityZoneNames = zonesResponse.availabilityZones().stream()
.map(software.amazon.awssdk.services.ec2.model.AvailabilityZone::zoneName)
.collect(Collectors.toList());
String availabilityZones = String.join(",", availabilityZoneNames);
LaunchTemplateSpecification specification = LaunchTemplateSpecification.builder()
.launchTemplateName(templateName)
.version("$Default")
.build();
String[] zones = availabilityZones.split(",");
CreateAutoScalingGroupRequest groupRequest = CreateAutoScalingGroupRequest.builder()
.launchTemplate(specification)
.availabilityZones(zones)
.maxSize(groupSize)
.minSize(groupSize)
.autoScalingGroupName(autoScalingGroupName)
.build();
try {
getAutoScalingClient().createAutoScalingGroup(groupRequest);
} catch (AutoScalingException e) {
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
}
System.out.println("Created an EC2 Auto Scaling group named " + autoScalingGroupName);
return zones;
}
public String getDefaultVPC() {
// Define the filter.
Filter defaultFilter = Filter.builder()
.name("is-default")
.values("true")
.build();
software.amazon.awssdk.services.ec2.model.DescribeVpcsRequest request = software.amazon.awssdk.services.ec2.model.DescribeVpcsRequest
.builder()
.filters(defaultFilter)
.build();
DescribeVpcsResponse response = getEc2Client().describeVpcs(request);
return response.vpcs().get(0).vpcId();
}
// Gets the default subnets in a VPC for a specified list of Availability Zones.
public List getSubnets(String vpcId, String[] availabilityZones) {
List subnets = null;
Filter vpcFilter = Filter.builder()
.name("vpc-id")
.values(vpcId)
.build();
Filter azFilter = Filter.builder()
.name("availability-zone")
.values(availabilityZones)
.build();
Filter defaultForAZ = Filter.builder()
.name("default-for-az")
.values("true")
.build();
DescribeSubnetsRequest request = DescribeSubnetsRequest.builder()
.filters(vpcFilter, azFilter, defaultForAZ)
.build();
DescribeSubnetsResponse response = getEc2Client().describeSubnets(request);
subnets = response.subnets();
return subnets;
}
// Gets data about the instances in the EC2 Auto Scaling group.
public String getBadInstance(String groupName) {
DescribeAutoScalingGroupsRequest request = DescribeAutoScalingGroupsRequest.builder()
.autoScalingGroupNames(groupName)
.build();
DescribeAutoScalingGroupsResponse response = getAutoScalingClient().describeAutoScalingGroups(request);
AutoScalingGroup autoScalingGroup = response.autoScalingGroups().get(0);
List instanceIds = autoScalingGroup.instances().stream()
.map(instance -> instance.instanceId())
.collect(Collectors.toList());
String[] instanceIdArray = instanceIds.toArray(new String[0]);
for (String instanceId : instanceIdArray) {
System.out.println("Instance ID: " + instanceId);
return instanceId;
}
return "";
}
// Gets data about the profile associated with an instance.
public String getInstanceProfile(String instanceId) {
Filter filter = Filter.builder()
.name("instance-id")
.values(instanceId)
.build();
DescribeIamInstanceProfileAssociationsRequest associationsRequest = DescribeIamInstanceProfileAssociationsRequest
.builder()
.filters(filter)
.build();
DescribeIamInstanceProfileAssociationsResponse response = getEc2Client()
.describeIamInstanceProfileAssociations(associationsRequest);
return response.iamInstanceProfileAssociations().get(0).associationId();
}
public void deleteRolesPolicies(String policyName, String roleName, String InstanceProfile) {
ListPoliciesRequest listPoliciesRequest = ListPoliciesRequest.builder().build();
ListPoliciesResponse listPoliciesResponse = getIAMClient().listPolicies(listPoliciesRequest);
for (Policy policy : listPoliciesResponse.policies()) {
if (policy.policyName().equals(policyName)) {
// List the entities (users, groups, roles) that are attached to the policy.
software.amazon.awssdk.services.iam.model.ListEntitiesForPolicyRequest listEntitiesRequest = software.amazon.awssdk.services.iam.model.ListEntitiesForPolicyRequest
.builder()
.policyArn(policy.arn())
.build();
ListEntitiesForPolicyResponse listEntitiesResponse = iamClient
.listEntitiesForPolicy(listEntitiesRequest);
if (!listEntitiesResponse.policyGroups().isEmpty() || !listEntitiesResponse.policyUsers().isEmpty()
|| !listEntitiesResponse.policyRoles().isEmpty()) {
// Detach the policy from any entities it is attached to.
DetachRolePolicyRequest detachPolicyRequest = DetachRolePolicyRequest.builder()
.policyArn(policy.arn())
.roleName(roleName) // Specify the name of the IAM role
.build();
getIAMClient().detachRolePolicy(detachPolicyRequest);
System.out.println("Policy detached from entities.");
}
// Now, you can delete the policy.
DeletePolicyRequest deletePolicyRequest = DeletePolicyRequest.builder()
.policyArn(policy.arn())
.build();
getIAMClient().deletePolicy(deletePolicyRequest);
System.out.println("Policy deleted successfully.");
break;
}
}
// List the roles associated with the instance profile
ListInstanceProfilesForRoleRequest listRolesRequest = ListInstanceProfilesForRoleRequest.builder()
.roleName(roleName)
.build();
// Detach the roles from the instance profile
ListInstanceProfilesForRoleResponse listRolesResponse = iamClient.listInstanceProfilesForRole(listRolesRequest);
for (software.amazon.awssdk.services.iam.model.InstanceProfile profile : listRolesResponse.instanceProfiles()) {
RemoveRoleFromInstanceProfileRequest removeRoleRequest = RemoveRoleFromInstanceProfileRequest.builder()
.instanceProfileName(InstanceProfile)
.roleName(roleName) // Remove the extra dot here
.build();
getIAMClient().removeRoleFromInstanceProfile(removeRoleRequest);
System.out.println("Role " + roleName + " removed from instance profile " + InstanceProfile);
}
// Delete the instance profile after removing all roles
DeleteInstanceProfileRequest deleteInstanceProfileRequest = DeleteInstanceProfileRequest.builder()
.instanceProfileName(InstanceProfile)
.build();
getIAMClient().deleteInstanceProfile(r -> r.instanceProfileName(InstanceProfile));
System.out.println(InstanceProfile + " Deleted");
System.out.println("All roles and policies are deleted.");
}
}
```
Create a class that wraps Elastic Load Balancing actions.
```
public class LoadBalancer {
public ElasticLoadBalancingV2Client elasticLoadBalancingV2Client;
public ElasticLoadBalancingV2Client getLoadBalancerClient() {
if (elasticLoadBalancingV2Client == null) {
elasticLoadBalancingV2Client = ElasticLoadBalancingV2Client.builder()
.region(Region.US_EAST_1)
.build();
}
return elasticLoadBalancingV2Client;
}
// Checks the health of the instances in the target group.
public List checkTargetHealth(String targetGroupName) {
DescribeTargetGroupsRequest targetGroupsRequest = DescribeTargetGroupsRequest.builder()
.names(targetGroupName)
.build();
DescribeTargetGroupsResponse tgResponse = getLoadBalancerClient().describeTargetGroups(targetGroupsRequest);
DescribeTargetHealthRequest healthRequest = DescribeTargetHealthRequest.builder()
.targetGroupArn(tgResponse.targetGroups().get(0).targetGroupArn())
.build();
DescribeTargetHealthResponse healthResponse = getLoadBalancerClient().describeTargetHealth(healthRequest);
return healthResponse.targetHealthDescriptions();
}
// Gets the HTTP endpoint of the load balancer.
public String getEndpoint(String lbName) {
DescribeLoadBalancersResponse res = getLoadBalancerClient()
.describeLoadBalancers(describe -> describe.names(lbName));
return res.loadBalancers().get(0).dnsName();
}
// Deletes a load balancer.
public void deleteLoadBalancer(String lbName) {
try {
// Use a waiter to delete the Load Balancer.
DescribeLoadBalancersResponse res = getLoadBalancerClient()
.describeLoadBalancers(describe -> describe.names(lbName));
ElasticLoadBalancingV2Waiter loadBalancerWaiter = getLoadBalancerClient().waiter();
DescribeLoadBalancersRequest request = DescribeLoadBalancersRequest.builder()
.loadBalancerArns(res.loadBalancers().get(0).loadBalancerArn())
.build();
getLoadBalancerClient().deleteLoadBalancer(
builder -> builder.loadBalancerArn(res.loadBalancers().get(0).loadBalancerArn()));
WaiterResponse waiterResponse = loadBalancerWaiter
.waitUntilLoadBalancersDeleted(request);
waiterResponse.matched().response().ifPresent(System.out::println);
} catch (ElasticLoadBalancingV2Exception e) {
System.err.println(e.awsErrorDetails().errorMessage());
}
System.out.println(lbName + " was deleted.");
}
// Deletes the target group.
public void deleteTargetGroup(String targetGroupName) {
try {
DescribeTargetGroupsResponse res = getLoadBalancerClient()
.describeTargetGroups(describe -> describe.names(targetGroupName));
getLoadBalancerClient()
.deleteTargetGroup(builder -> builder.targetGroupArn(res.targetGroups().get(0).targetGroupArn()));
} catch (ElasticLoadBalancingV2Exception e) {
System.err.println(e.awsErrorDetails().errorMessage());
}
System.out.println(targetGroupName + " was deleted.");
}
// Verify this computer can successfully send a GET request to the load balancer
// endpoint.
public boolean verifyLoadBalancerEndpoint(String elbDnsName) throws IOException, InterruptedException {
boolean success = false;
int retries = 3;
CloseableHttpClient httpClient = HttpClients.createDefault();
// Create an HTTP GET request to the ELB.
HttpGet httpGet = new HttpGet("http://" + elbDnsName);
try {
while ((!success) && (retries > 0)) {
// Execute the request and get the response.
HttpResponse response = httpClient.execute(httpGet);
int statusCode = response.getStatusLine().getStatusCode();
System.out.println("HTTP Status Code: " + statusCode);
if (statusCode == 200) {
success = true;
} else {
retries--;
System.out.println("Got connection error from load balancer endpoint, retrying...");
TimeUnit.SECONDS.sleep(15);
}
}
} catch (org.apache.http.conn.HttpHostConnectException e) {
System.out.println(e.getMessage());
}
System.out.println("Status.." + success);
return success;
}
/*
* Creates an Elastic Load Balancing target group. The target group specifies
* how
* the load balancer forward requests to instances in the group and how instance
* health is checked.
*/
public String createTargetGroup(String protocol, int port, String vpcId, String targetGroupName) {
CreateTargetGroupRequest targetGroupRequest = CreateTargetGroupRequest.builder()
.healthCheckPath("/healthcheck")
.healthCheckTimeoutSeconds(5)
.port(port)
.vpcId(vpcId)
.name(targetGroupName)
.protocol(protocol)
.build();
CreateTargetGroupResponse targetGroupResponse = getLoadBalancerClient().createTargetGroup(targetGroupRequest);
String targetGroupArn = targetGroupResponse.targetGroups().get(0).targetGroupArn();
String targetGroup = targetGroupResponse.targetGroups().get(0).targetGroupName();
System.out.println("The " + targetGroup + " was created with ARN" + targetGroupArn);
return targetGroupArn;
}
/*
* Creates an Elastic Load Balancing load balancer that uses the specified
* subnets
* and forwards requests to the specified target group.
*/
public String createLoadBalancer(List subnetIds, String targetGroupARN, String lbName, int port,
String protocol) {
try {
List subnetIdStrings = subnetIds.stream()
.map(Subnet::subnetId)
.collect(Collectors.toList());
CreateLoadBalancerRequest balancerRequest = CreateLoadBalancerRequest.builder()
.subnets(subnetIdStrings)
.name(lbName)
.scheme("internet-facing")
.build();
// Create and wait for the load balancer to become available.
CreateLoadBalancerResponse lsResponse = getLoadBalancerClient().createLoadBalancer(balancerRequest);
String lbARN = lsResponse.loadBalancers().get(0).loadBalancerArn();
ElasticLoadBalancingV2Waiter loadBalancerWaiter = getLoadBalancerClient().waiter();
DescribeLoadBalancersRequest request = DescribeLoadBalancersRequest.builder()
.loadBalancerArns(lbARN)
.build();
System.out.println("Waiting for Load Balancer " + lbName + " to become available.");
WaiterResponse waiterResponse = loadBalancerWaiter
.waitUntilLoadBalancerAvailable(request);
waiterResponse.matched().response().ifPresent(System.out::println);
System.out.println("Load Balancer " + lbName + " is available.");
// Get the DNS name (endpoint) of the load balancer.
String lbDNSName = lsResponse.loadBalancers().get(0).dnsName();
System.out.println("*** Load Balancer DNS Name: " + lbDNSName);
// Create a listener for the load balance.
Action action = Action.builder()
.targetGroupArn(targetGroupARN)
.type("forward")
.build();
CreateListenerRequest listenerRequest = CreateListenerRequest.builder()
.loadBalancerArn(lsResponse.loadBalancers().get(0).loadBalancerArn())
.defaultActions(action)
.port(port)
.protocol(protocol)
.build();
getLoadBalancerClient().createListener(listenerRequest);
System.out.println("Created listener to forward traffic from load balancer " + lbName + " to target group "
+ targetGroupARN);
// Return the load balancer DNS name.
return lbDNSName;
} catch (ElasticLoadBalancingV2Exception e) {
e.printStackTrace();
}
return "";
}
}
```
Create a class that uses DynamoDB to simulate a recommendation service.
```
public class Database {
private static DynamoDbClient dynamoDbClient;
public static DynamoDbClient getDynamoDbClient() {
if (dynamoDbClient == null) {
dynamoDbClient = DynamoDbClient.builder()
.region(Region.US_EAST_1)
.build();
}
return dynamoDbClient;
}
// Checks to see if the Amazon DynamoDB table exists.
private boolean doesTableExist(String tableName) {
try {
// Describe the table and catch any exceptions.
DescribeTableRequest describeTableRequest = DescribeTableRequest.builder()
.tableName(tableName)
.build();
getDynamoDbClient().describeTable(describeTableRequest);
System.out.println("Table '" + tableName + "' exists.");
return true;
} catch (ResourceNotFoundException e) {
System.out.println("Table '" + tableName + "' does not exist.");
} catch (DynamoDbException e) {
System.err.println("Error checking table existence: " + e.getMessage());
}
return false;
}
/*
* Creates a DynamoDB table to use a recommendation service. The table has a
* hash key named 'MediaType' that defines the type of media recommended, such
* as
* Book or Movie, and a range key named 'ItemId' that, combined with the
* MediaType,
* forms a unique identifier for the recommended item.
*/
public void createTable(String tableName, String fileName) throws IOException {
// First check to see if the table exists.
boolean doesExist = doesTableExist(tableName);
if (!doesExist) {
DynamoDbWaiter dbWaiter = getDynamoDbClient().waiter();
CreateTableRequest createTableRequest = CreateTableRequest.builder()
.tableName(tableName)
.attributeDefinitions(
AttributeDefinition.builder()
.attributeName("MediaType")
.attributeType(ScalarAttributeType.S)
.build(),
AttributeDefinition.builder()
.attributeName("ItemId")
.attributeType(ScalarAttributeType.N)
.build())
.keySchema(
KeySchemaElement.builder()
.attributeName("MediaType")
.keyType(KeyType.HASH)
.build(),
KeySchemaElement.builder()
.attributeName("ItemId")
.keyType(KeyType.RANGE)
.build())
.provisionedThroughput(
ProvisionedThroughput.builder()
.readCapacityUnits(5L)
.writeCapacityUnits(5L)
.build())
.build();
getDynamoDbClient().createTable(createTableRequest);
System.out.println("Creating table " + tableName + "...");
// Wait until the Amazon DynamoDB table is created.
DescribeTableRequest tableRequest = DescribeTableRequest.builder()
.tableName(tableName)
.build();
WaiterResponse waiterResponse = dbWaiter.waitUntilTableExists(tableRequest);
waiterResponse.matched().response().ifPresent(System.out::println);
System.out.println("Table " + tableName + " created.");
// Add records to the table.
populateTable(fileName, tableName);
}
}
public void deleteTable(String tableName) {
getDynamoDbClient().deleteTable(table -> table.tableName(tableName));
System.out.println("Table " + tableName + " deleted.");
}
// Populates the table with data located in a JSON file using the DynamoDB
// enhanced client.
public void populateTable(String fileName, String tableName) throws IOException {
DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
.dynamoDbClient(getDynamoDbClient())
.build();
ObjectMapper objectMapper = new ObjectMapper();
File jsonFile = new File(fileName);
JsonNode rootNode = objectMapper.readTree(jsonFile);
DynamoDbTable mappedTable = enhancedClient.table(tableName,
TableSchema.fromBean(Recommendation.class));
for (JsonNode currentNode : rootNode) {
String mediaType = currentNode.path("MediaType").path("S").asText();
int itemId = currentNode.path("ItemId").path("N").asInt();
String title = currentNode.path("Title").path("S").asText();
String creator = currentNode.path("Creator").path("S").asText();
// Create a Recommendation object and set its properties.
Recommendation rec = new Recommendation();
rec.setMediaType(mediaType);
rec.setItemId(itemId);
rec.setTitle(title);
rec.setCreator(creator);
// Put the item into the DynamoDB table.
mappedTable.putItem(rec); // Add the Recommendation to the list.
}
System.out.println("Added all records to the " + tableName);
}
}
```
Create a class that wraps Systems Manager actions.
```
public class ParameterHelper {
String tableName = "doc-example-resilient-architecture-table";
String dyntable = "doc-example-recommendation-service";
String failureResponse = "doc-example-resilient-architecture-failure-response";
String healthCheck = "doc-example-resilient-architecture-health-check";
public void reset() {
put(dyntable, tableName);
put(failureResponse, "none");
put(healthCheck, "shallow");
}
public void put(String name, String value) {
SsmClient ssmClient = SsmClient.builder()
.region(Region.US_EAST_1)
.build();
PutParameterRequest parameterRequest = PutParameterRequest.builder()
.name(name)
.value(value)
.overwrite(true)
.type("String")
.build();
ssmClient.putParameter(parameterRequest);
System.out.printf("Setting demo parameter %s to '%s'.", name, value);
}
}
```
+ For API details, see the following topics in *AWS SDK for Java 2.x API Reference*.
+ [AttachLoadBalancerTargetGroups](https://docs.aws.amazon.com/goto/SdkForJavaV2/autoscaling-2011-01-01/AttachLoadBalancerTargetGroups)
+ [CreateAutoScalingGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/autoscaling-2011-01-01/CreateAutoScalingGroup)
+ [CreateInstanceProfile](https://docs.aws.amazon.com/goto/SdkForJavaV2/iam-2010-05-08/CreateInstanceProfile)
+ [CreateLaunchTemplate](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/CreateLaunchTemplate)
+ [CreateListener](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/CreateListener)
+ [CreateLoadBalancer](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/CreateLoadBalancer)
+ [CreateTargetGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/CreateTargetGroup)
+ [DeleteAutoScalingGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/autoscaling-2011-01-01/DeleteAutoScalingGroup)
+ [DeleteInstanceProfile](https://docs.aws.amazon.com/goto/SdkForJavaV2/iam-2010-05-08/DeleteInstanceProfile)
+ [DeleteLaunchTemplate](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/DeleteLaunchTemplate)
+ [DeleteLoadBalancer](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DeleteLoadBalancer)
+ [DeleteTargetGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DeleteTargetGroup)
+ [DescribeAutoScalingGroups](https://docs.aws.amazon.com/goto/SdkForJavaV2/autoscaling-2011-01-01/DescribeAutoScalingGroups)
+ [DescribeAvailabilityZones](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/DescribeAvailabilityZones)
+ [DescribeIamInstanceProfileAssociations](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/DescribeIamInstanceProfileAssociations)
+ [DescribeInstances](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/DescribeInstances)
+ [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers)
+ [DescribeSubnets](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/DescribeSubnets)
+ [DescribeTargetGroups](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DescribeTargetGroups)
+ [DescribeTargetHealth](https://docs.aws.amazon.com/goto/SdkForJavaV2/elasticloadbalancingv2-2015-12-01/DescribeTargetHealth)
+ [DescribeVpcs](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/DescribeVpcs)
+ [RebootInstances](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/RebootInstances)
+ [ReplaceIamInstanceProfileAssociation](https://docs.aws.amazon.com/goto/SdkForJavaV2/ec2-2016-11-15/ReplaceIamInstanceProfileAssociation)
+ [TerminateInstanceInAutoScalingGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/autoscaling-2011-01-01/TerminateInstanceInAutoScalingGroup)
+ [UpdateAutoScalingGroup](https://docs.aws.amazon.com/goto/SdkForJavaV2/autoscaling-2011-01-01/UpdateAutoScalingGroup)
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-resilient-service#code-examples).
Run the interactive scenario at a command prompt.
```
#!/usr/bin/env node
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import {
Scenario,
parseScenarioArgs,
} from "@aws-doc-sdk-examples/lib/scenario/index.js";
/**
* The workflow steps are split into three stages:
* - deploy
* - demo
* - destroy
*
* Each of these stages has a corresponding file prefixed with steps-*.
*/
import { deploySteps } from "./steps-deploy.js";
import { demoSteps } from "./steps-demo.js";
import { destroySteps } from "./steps-destroy.js";
/**
* The context is passed to every scenario. Scenario steps
* will modify the context.
*/
const context = {};
/**
* Three Scenarios are created for the workflow. A Scenario is an orchestration class
* that simplifies running a series of steps.
*/
export const scenarios = {
// Deploys all resources necessary for the workflow.
deploy: new Scenario("Resilient Workflow - Deploy", deploySteps, context),
// Demonstrates how a fragile web service can be made more resilient.
demo: new Scenario("Resilient Workflow - Demo", demoSteps, context),
// Destroys the resources created for the workflow.
destroy: new Scenario("Resilient Workflow - Destroy", destroySteps, context),
};
// Call function if run directly
import { fileURLToPath } from "node:url";
if (process.argv[1] === fileURLToPath(import.meta.url)) {
parseScenarioArgs(scenarios, {
name: "Resilient Workflow",
synopsis:
"node index.js --scenario [-h|--help] [-y|--yes] [-v|--verbose]",
description: "Deploy and interact with scalable EC2 instances.",
});
}
```
Create steps to deploy all of the resources.
```
import { join } from "node:path";
import { readFileSync, writeFileSync } from "node:fs";
import axios from "axios";
import {
BatchWriteItemCommand,
CreateTableCommand,
DynamoDBClient,
waitUntilTableExists,
} from "@aws-sdk/client-dynamodb";
import {
EC2Client,
CreateKeyPairCommand,
CreateLaunchTemplateCommand,
DescribeAvailabilityZonesCommand,
DescribeVpcsCommand,
DescribeSubnetsCommand,
DescribeSecurityGroupsCommand,
AuthorizeSecurityGroupIngressCommand,
} from "@aws-sdk/client-ec2";
import {
IAMClient,
CreatePolicyCommand,
CreateRoleCommand,
CreateInstanceProfileCommand,
AddRoleToInstanceProfileCommand,
AttachRolePolicyCommand,
waitUntilInstanceProfileExists,
} from "@aws-sdk/client-iam";
import { SSMClient, GetParameterCommand } from "@aws-sdk/client-ssm";
import {
CreateAutoScalingGroupCommand,
AutoScalingClient,
AttachLoadBalancerTargetGroupsCommand,
} from "@aws-sdk/client-auto-scaling";
import {
CreateListenerCommand,
CreateLoadBalancerCommand,
CreateTargetGroupCommand,
ElasticLoadBalancingV2Client,
waitUntilLoadBalancerAvailable,
} from "@aws-sdk/client-elastic-load-balancing-v2";
import {
ScenarioOutput,
ScenarioInput,
ScenarioAction,
} from "@aws-doc-sdk-examples/lib/scenario/index.js";
import { saveState } from "@aws-doc-sdk-examples/lib/scenario/steps-common.js";
import { retry } from "@aws-doc-sdk-examples/lib/utils/util-timers.js";
import { MESSAGES, NAMES, RESOURCES_PATH, ROOT } from "./constants.js";
import { initParamsSteps } from "./steps-reset-params.js";
/**
* @type {import('@aws-doc-sdk-examples/lib/scenario.js').Step[]}
*/
export const deploySteps = [
new ScenarioOutput("introduction", MESSAGES.introduction, { header: true }),
new ScenarioInput("confirmDeployment", MESSAGES.confirmDeployment, {
type: "confirm",
}),
new ScenarioAction(
"handleConfirmDeployment",
(c) => c.confirmDeployment === false && process.exit(),
),
new ScenarioOutput(
"creatingTable",
MESSAGES.creatingTable.replace("${TABLE_NAME}", NAMES.tableName),
),
new ScenarioAction("createTable", async () => {
const client = new DynamoDBClient({});
await client.send(
new CreateTableCommand({
TableName: NAMES.tableName,
ProvisionedThroughput: {
ReadCapacityUnits: 5,
WriteCapacityUnits: 5,
},
AttributeDefinitions: [
{
AttributeName: "MediaType",
AttributeType: "S",
},
{
AttributeName: "ItemId",
AttributeType: "N",
},
],
KeySchema: [
{
AttributeName: "MediaType",
KeyType: "HASH",
},
{
AttributeName: "ItemId",
KeyType: "RANGE",
},
],
}),
);
await waitUntilTableExists({ client }, { TableName: NAMES.tableName });
}),
new ScenarioOutput(
"createdTable",
MESSAGES.createdTable.replace("${TABLE_NAME}", NAMES.tableName),
),
new ScenarioOutput(
"populatingTable",
MESSAGES.populatingTable.replace("${TABLE_NAME}", NAMES.tableName),
),
new ScenarioAction("populateTable", () => {
const client = new DynamoDBClient({});
/**
* @type {{ default: import("@aws-sdk/client-dynamodb").PutRequest['Item'][] }}
*/
const recommendations = JSON.parse(
readFileSync(join(RESOURCES_PATH, "recommendations.json")),
);
return client.send(
new BatchWriteItemCommand({
RequestItems: {
[NAMES.tableName]: recommendations.map((item) => ({
PutRequest: { Item: item },
})),
},
}),
);
}),
new ScenarioOutput(
"populatedTable",
MESSAGES.populatedTable.replace("${TABLE_NAME}", NAMES.tableName),
),
new ScenarioOutput(
"creatingKeyPair",
MESSAGES.creatingKeyPair.replace("${KEY_PAIR_NAME}", NAMES.keyPairName),
),
new ScenarioAction("createKeyPair", async () => {
const client = new EC2Client({});
const { KeyMaterial } = await client.send(
new CreateKeyPairCommand({
KeyName: NAMES.keyPairName,
}),
);
writeFileSync(`${NAMES.keyPairName}.pem`, KeyMaterial, { mode: 0o600 });
}),
new ScenarioOutput(
"createdKeyPair",
MESSAGES.createdKeyPair.replace("${KEY_PAIR_NAME}", NAMES.keyPairName),
),
new ScenarioOutput(
"creatingInstancePolicy",
MESSAGES.creatingInstancePolicy.replace(
"${INSTANCE_POLICY_NAME}",
NAMES.instancePolicyName,
),
),
new ScenarioAction("createInstancePolicy", async (state) => {
const client = new IAMClient({});
const {
Policy: { Arn },
} = await client.send(
new CreatePolicyCommand({
PolicyName: NAMES.instancePolicyName,
PolicyDocument: readFileSync(
join(RESOURCES_PATH, "instance_policy.json"),
),
}),
);
state.instancePolicyArn = Arn;
}),
new ScenarioOutput("createdInstancePolicy", (state) =>
MESSAGES.createdInstancePolicy
.replace("${INSTANCE_POLICY_NAME}", NAMES.instancePolicyName)
.replace("${INSTANCE_POLICY_ARN}", state.instancePolicyArn),
),
new ScenarioOutput(
"creatingInstanceRole",
MESSAGES.creatingInstanceRole.replace(
"${INSTANCE_ROLE_NAME}",
NAMES.instanceRoleName,
),
),
new ScenarioAction("createInstanceRole", () => {
const client = new IAMClient({});
return client.send(
new CreateRoleCommand({
RoleName: NAMES.instanceRoleName,
AssumeRolePolicyDocument: readFileSync(
join(ROOT, "assume-role-policy.json"),
),
}),
);
}),
new ScenarioOutput(
"createdInstanceRole",
MESSAGES.createdInstanceRole.replace(
"${INSTANCE_ROLE_NAME}",
NAMES.instanceRoleName,
),
),
new ScenarioOutput(
"attachingPolicyToRole",
MESSAGES.attachingPolicyToRole
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName)
.replace("${INSTANCE_POLICY_NAME}", NAMES.instancePolicyName),
),
new ScenarioAction("attachPolicyToRole", async (state) => {
const client = new IAMClient({});
await client.send(
new AttachRolePolicyCommand({
RoleName: NAMES.instanceRoleName,
PolicyArn: state.instancePolicyArn,
}),
);
}),
new ScenarioOutput(
"attachedPolicyToRole",
MESSAGES.attachedPolicyToRole
.replace("${INSTANCE_POLICY_NAME}", NAMES.instancePolicyName)
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName),
),
new ScenarioOutput(
"creatingInstanceProfile",
MESSAGES.creatingInstanceProfile.replace(
"${INSTANCE_PROFILE_NAME}",
NAMES.instanceProfileName,
),
),
new ScenarioAction("createInstanceProfile", async (state) => {
const client = new IAMClient({});
const {
InstanceProfile: { Arn },
} = await client.send(
new CreateInstanceProfileCommand({
InstanceProfileName: NAMES.instanceProfileName,
}),
);
state.instanceProfileArn = Arn;
await waitUntilInstanceProfileExists(
{ client },
{ InstanceProfileName: NAMES.instanceProfileName },
);
}),
new ScenarioOutput("createdInstanceProfile", (state) =>
MESSAGES.createdInstanceProfile
.replace("${INSTANCE_PROFILE_NAME}", NAMES.instanceProfileName)
.replace("${INSTANCE_PROFILE_ARN}", state.instanceProfileArn),
),
new ScenarioOutput(
"addingRoleToInstanceProfile",
MESSAGES.addingRoleToInstanceProfile
.replace("${INSTANCE_PROFILE_NAME}", NAMES.instanceProfileName)
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName),
),
new ScenarioAction("addRoleToInstanceProfile", () => {
const client = new IAMClient({});
return client.send(
new AddRoleToInstanceProfileCommand({
RoleName: NAMES.instanceRoleName,
InstanceProfileName: NAMES.instanceProfileName,
}),
);
}),
new ScenarioOutput(
"addedRoleToInstanceProfile",
MESSAGES.addedRoleToInstanceProfile
.replace("${INSTANCE_PROFILE_NAME}", NAMES.instanceProfileName)
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName),
),
...initParamsSteps,
new ScenarioOutput("creatingLaunchTemplate", MESSAGES.creatingLaunchTemplate),
new ScenarioAction("createLaunchTemplate", async () => {
const ssmClient = new SSMClient({});
const { Parameter } = await ssmClient.send(
new GetParameterCommand({
Name: "/aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2",
}),
);
const ec2Client = new EC2Client({});
await ec2Client.send(
new CreateLaunchTemplateCommand({
LaunchTemplateName: NAMES.launchTemplateName,
LaunchTemplateData: {
InstanceType: "t3.micro",
ImageId: Parameter.Value,
IamInstanceProfile: { Name: NAMES.instanceProfileName },
UserData: readFileSync(
join(RESOURCES_PATH, "server_startup_script.sh"),
).toString("base64"),
KeyName: NAMES.keyPairName,
},
}),
);
}),
new ScenarioOutput(
"createdLaunchTemplate",
MESSAGES.createdLaunchTemplate.replace(
"${LAUNCH_TEMPLATE_NAME}",
NAMES.launchTemplateName,
),
),
new ScenarioOutput(
"creatingAutoScalingGroup",
MESSAGES.creatingAutoScalingGroup.replace(
"${AUTO_SCALING_GROUP_NAME}",
NAMES.autoScalingGroupName,
),
),
new ScenarioAction("createAutoScalingGroup", async (state) => {
const ec2Client = new EC2Client({});
const { AvailabilityZones } = await ec2Client.send(
new DescribeAvailabilityZonesCommand({}),
);
state.availabilityZoneNames = AvailabilityZones.map((az) => az.ZoneName);
const autoScalingClient = new AutoScalingClient({});
await retry({ intervalInMs: 1000, maxRetries: 30 }, () =>
autoScalingClient.send(
new CreateAutoScalingGroupCommand({
AvailabilityZones: state.availabilityZoneNames,
AutoScalingGroupName: NAMES.autoScalingGroupName,
LaunchTemplate: {
LaunchTemplateName: NAMES.launchTemplateName,
Version: "$Default",
},
MinSize: 3,
MaxSize: 3,
}),
),
);
}),
new ScenarioOutput(
"createdAutoScalingGroup",
/**
* @param {{ availabilityZoneNames: string[] }} state
*/
(state) =>
MESSAGES.createdAutoScalingGroup
.replace("${AUTO_SCALING_GROUP_NAME}", NAMES.autoScalingGroupName)
.replace(
"${AVAILABILITY_ZONE_NAMES}",
state.availabilityZoneNames.join(", "),
),
),
new ScenarioInput("confirmContinue", MESSAGES.confirmContinue, {
type: "confirm",
}),
new ScenarioOutput("loadBalancer", MESSAGES.loadBalancer),
new ScenarioOutput("gettingVpc", MESSAGES.gettingVpc),
new ScenarioAction("getVpc", async (state) => {
const client = new EC2Client({});
const { Vpcs } = await client.send(
new DescribeVpcsCommand({
Filters: [{ Name: "is-default", Values: ["true"] }],
}),
);
state.defaultVpc = Vpcs[0].VpcId;
}),
new ScenarioOutput("gotVpc", (state) =>
MESSAGES.gotVpc.replace("${VPC_ID}", state.defaultVpc),
),
new ScenarioOutput("gettingSubnets", MESSAGES.gettingSubnets),
new ScenarioAction("getSubnets", async (state) => {
const client = new EC2Client({});
const { Subnets } = await client.send(
new DescribeSubnetsCommand({
Filters: [
{ Name: "vpc-id", Values: [state.defaultVpc] },
{ Name: "availability-zone", Values: state.availabilityZoneNames },
{ Name: "default-for-az", Values: ["true"] },
],
}),
);
state.subnets = Subnets.map((subnet) => subnet.SubnetId);
}),
new ScenarioOutput(
"gotSubnets",
/**
* @param {{ subnets: string[] }} state
*/
(state) =>
MESSAGES.gotSubnets.replace("${SUBNETS}", state.subnets.join(", ")),
),
new ScenarioOutput(
"creatingLoadBalancerTargetGroup",
MESSAGES.creatingLoadBalancerTargetGroup.replace(
"${TARGET_GROUP_NAME}",
NAMES.loadBalancerTargetGroupName,
),
),
new ScenarioAction("createLoadBalancerTargetGroup", async (state) => {
const client = new ElasticLoadBalancingV2Client({});
const { TargetGroups } = await client.send(
new CreateTargetGroupCommand({
Name: NAMES.loadBalancerTargetGroupName,
Protocol: "HTTP",
Port: 80,
HealthCheckPath: "/healthcheck",
HealthCheckIntervalSeconds: 10,
HealthCheckTimeoutSeconds: 5,
HealthyThresholdCount: 2,
UnhealthyThresholdCount: 2,
VpcId: state.defaultVpc,
}),
);
const targetGroup = TargetGroups[0];
state.targetGroupArn = targetGroup.TargetGroupArn;
state.targetGroupProtocol = targetGroup.Protocol;
state.targetGroupPort = targetGroup.Port;
}),
new ScenarioOutput(
"createdLoadBalancerTargetGroup",
MESSAGES.createdLoadBalancerTargetGroup.replace(
"${TARGET_GROUP_NAME}",
NAMES.loadBalancerTargetGroupName,
),
),
new ScenarioOutput(
"creatingLoadBalancer",
MESSAGES.creatingLoadBalancer.replace("${LB_NAME}", NAMES.loadBalancerName),
),
new ScenarioAction("createLoadBalancer", async (state) => {
const client = new ElasticLoadBalancingV2Client({});
const { LoadBalancers } = await client.send(
new CreateLoadBalancerCommand({
Name: NAMES.loadBalancerName,
Subnets: state.subnets,
}),
);
state.loadBalancerDns = LoadBalancers[0].DNSName;
state.loadBalancerArn = LoadBalancers[0].LoadBalancerArn;
await waitUntilLoadBalancerAvailable(
{ client },
{ Names: [NAMES.loadBalancerName] },
);
}),
new ScenarioOutput("createdLoadBalancer", (state) =>
MESSAGES.createdLoadBalancer
.replace("${LB_NAME}", NAMES.loadBalancerName)
.replace("${DNS_NAME}", state.loadBalancerDns),
),
new ScenarioOutput(
"creatingListener",
MESSAGES.creatingLoadBalancerListener
.replace("${LB_NAME}", NAMES.loadBalancerName)
.replace("${TARGET_GROUP_NAME}", NAMES.loadBalancerTargetGroupName),
),
new ScenarioAction("createListener", async (state) => {
const client = new ElasticLoadBalancingV2Client({});
const { Listeners } = await client.send(
new CreateListenerCommand({
LoadBalancerArn: state.loadBalancerArn,
Protocol: state.targetGroupProtocol,
Port: state.targetGroupPort,
DefaultActions: [
{ Type: "forward", TargetGroupArn: state.targetGroupArn },
],
}),
);
const listener = Listeners[0];
state.loadBalancerListenerArn = listener.ListenerArn;
}),
new ScenarioOutput("createdListener", (state) =>
MESSAGES.createdLoadBalancerListener.replace(
"${LB_LISTENER_ARN}",
state.loadBalancerListenerArn,
),
),
new ScenarioOutput(
"attachingLoadBalancerTargetGroup",
MESSAGES.attachingLoadBalancerTargetGroup
.replace("${TARGET_GROUP_NAME}", NAMES.loadBalancerTargetGroupName)
.replace("${AUTO_SCALING_GROUP_NAME}", NAMES.autoScalingGroupName),
),
new ScenarioAction("attachLoadBalancerTargetGroup", async (state) => {
const client = new AutoScalingClient({});
await client.send(
new AttachLoadBalancerTargetGroupsCommand({
AutoScalingGroupName: NAMES.autoScalingGroupName,
TargetGroupARNs: [state.targetGroupArn],
}),
);
}),
new ScenarioOutput(
"attachedLoadBalancerTargetGroup",
MESSAGES.attachedLoadBalancerTargetGroup,
),
new ScenarioOutput("verifyingInboundPort", MESSAGES.verifyingInboundPort),
new ScenarioAction(
"verifyInboundPort",
/**
*
* @param {{ defaultSecurityGroup: import('@aws-sdk/client-ec2').SecurityGroup}} state
*/
async (state) => {
const client = new EC2Client({});
const { SecurityGroups } = await client.send(
new DescribeSecurityGroupsCommand({
Filters: [{ Name: "group-name", Values: ["default"] }],
}),
);
if (!SecurityGroups) {
state.verifyInboundPortError = new Error(MESSAGES.noSecurityGroups);
}
state.defaultSecurityGroup = SecurityGroups[0];
/**
* @type {string}
*/
const ipResponse = (await axios.get("http://checkip.amazonaws.com")).data;
state.myIp = ipResponse.trim();
const myIpRules = state.defaultSecurityGroup.IpPermissions.filter(
({ IpRanges }) =>
IpRanges.some(
({ CidrIp }) =>
CidrIp.startsWith(state.myIp) || CidrIp === "0.0.0.0/0",
),
)
.filter(({ IpProtocol }) => IpProtocol === "tcp")
.filter(({ FromPort }) => FromPort === 80);
state.myIpRules = myIpRules;
},
),
new ScenarioOutput(
"verifiedInboundPort",
/**
* @param {{ myIpRules: any[] }} state
*/
(state) => {
if (state.myIpRules.length > 0) {
return MESSAGES.foundIpRules.replace(
"${IP_RULES}",
JSON.stringify(state.myIpRules, null, 2),
);
}
return MESSAGES.noIpRules;
},
),
new ScenarioInput(
"shouldAddInboundRule",
/**
* @param {{ myIpRules: any[] }} state
*/
(state) => {
if (state.myIpRules.length > 0) {
return false;
}
return MESSAGES.noIpRules;
},
{ type: "confirm" },
),
new ScenarioAction(
"addInboundRule",
/**
* @param {{ defaultSecurityGroup: import('@aws-sdk/client-ec2').SecurityGroup }} state
*/
async (state) => {
if (!state.shouldAddInboundRule) {
return;
}
const client = new EC2Client({});
await client.send(
new AuthorizeSecurityGroupIngressCommand({
GroupId: state.defaultSecurityGroup.GroupId,
CidrIp: `${state.myIp}/32`,
FromPort: 80,
ToPort: 80,
IpProtocol: "tcp",
}),
);
},
),
new ScenarioOutput("addedInboundRule", (state) => {
if (state.shouldAddInboundRule) {
return MESSAGES.addedInboundRule.replace("${IP_ADDRESS}", state.myIp);
}
return false;
}),
new ScenarioOutput("verifyingEndpoint", (state) =>
MESSAGES.verifyingEndpoint.replace("${DNS_NAME}", state.loadBalancerDns),
),
new ScenarioAction("verifyEndpoint", async (state) => {
try {
const response = await retry({ intervalInMs: 2000, maxRetries: 30 }, () =>
axios.get(`http://${state.loadBalancerDns}`),
);
state.endpointResponse = JSON.stringify(response.data, null, 2);
} catch (e) {
state.verifyEndpointError = e;
}
}),
new ScenarioOutput("verifiedEndpoint", (state) => {
if (state.verifyEndpointError) {
console.error(state.verifyEndpointError);
} else {
return MESSAGES.verifiedEndpoint.replace(
"${ENDPOINT_RESPONSE}",
state.endpointResponse,
);
}
}),
saveState,
];
```
Create steps to run the demo.
```
import { readFileSync } from "node:fs";
import { join } from "node:path";
import axios from "axios";
import {
DescribeTargetGroupsCommand,
DescribeTargetHealthCommand,
ElasticLoadBalancingV2Client,
} from "@aws-sdk/client-elastic-load-balancing-v2";
import {
DescribeInstanceInformationCommand,
PutParameterCommand,
SSMClient,
SendCommandCommand,
} from "@aws-sdk/client-ssm";
import {
IAMClient,
CreatePolicyCommand,
CreateRoleCommand,
AttachRolePolicyCommand,
CreateInstanceProfileCommand,
AddRoleToInstanceProfileCommand,
waitUntilInstanceProfileExists,
} from "@aws-sdk/client-iam";
import {
AutoScalingClient,
DescribeAutoScalingGroupsCommand,
TerminateInstanceInAutoScalingGroupCommand,
} from "@aws-sdk/client-auto-scaling";
import {
DescribeIamInstanceProfileAssociationsCommand,
EC2Client,
RebootInstancesCommand,
ReplaceIamInstanceProfileAssociationCommand,
} from "@aws-sdk/client-ec2";
import {
ScenarioAction,
ScenarioInput,
ScenarioOutput,
} from "@aws-doc-sdk-examples/lib/scenario/scenario.js";
import { retry } from "@aws-doc-sdk-examples/lib/utils/util-timers.js";
import { MESSAGES, NAMES, RESOURCES_PATH } from "./constants.js";
import { findLoadBalancer } from "./shared.js";
const getRecommendation = new ScenarioAction(
"getRecommendation",
async (state) => {
const loadBalancer = await findLoadBalancer(NAMES.loadBalancerName);
if (loadBalancer) {
state.loadBalancerDnsName = loadBalancer.DNSName;
try {
state.recommendation = (
await axios.get(`http://${state.loadBalancerDnsName}`)
).data;
} catch (e) {
state.recommendation = e instanceof Error ? e.message : e;
}
} else {
throw new Error(MESSAGES.demoFindLoadBalancerError);
}
},
);
const getRecommendationResult = new ScenarioOutput(
"getRecommendationResult",
(state) =>
`Recommendation:\n${JSON.stringify(state.recommendation, null, 2)}`,
{ preformatted: true },
);
const getHealthCheck = new ScenarioAction("getHealthCheck", async (state) => {
const client = new ElasticLoadBalancingV2Client({});
const { TargetGroups } = await client.send(
new DescribeTargetGroupsCommand({
Names: [NAMES.loadBalancerTargetGroupName],
}),
);
const { TargetHealthDescriptions } = await client.send(
new DescribeTargetHealthCommand({
TargetGroupArn: TargetGroups[0].TargetGroupArn,
}),
);
state.targetHealthDescriptions = TargetHealthDescriptions;
});
const getHealthCheckResult = new ScenarioOutput(
"getHealthCheckResult",
/**
* @param {{ targetHealthDescriptions: import('@aws-sdk/client-elastic-load-balancing-v2').TargetHealthDescription[]}} state
*/
(state) => {
const status = state.targetHealthDescriptions
.map((th) => `${th.Target.Id}: ${th.TargetHealth.State}`)
.join("\n");
return `Health check:\n${status}`;
},
{ preformatted: true },
);
const loadBalancerLoop = new ScenarioAction(
"loadBalancerLoop",
getRecommendation.action,
{
whileConfig: {
whileFn: ({ loadBalancerCheck }) => loadBalancerCheck,
input: new ScenarioInput(
"loadBalancerCheck",
MESSAGES.demoLoadBalancerCheck,
{
type: "confirm",
},
),
output: getRecommendationResult,
},
},
);
const healthCheckLoop = new ScenarioAction(
"healthCheckLoop",
getHealthCheck.action,
{
whileConfig: {
whileFn: ({ healthCheck }) => healthCheck,
input: new ScenarioInput("healthCheck", MESSAGES.demoHealthCheck, {
type: "confirm",
}),
output: getHealthCheckResult,
},
},
);
const statusSteps = [
getRecommendation,
getRecommendationResult,
getHealthCheck,
getHealthCheckResult,
];
/**
* @type {import('@aws-doc-sdk-examples/lib/scenario.js').Step[]}
*/
export const demoSteps = [
new ScenarioOutput("header", MESSAGES.demoHeader, { header: true }),
new ScenarioOutput("sanityCheck", MESSAGES.demoSanityCheck),
...statusSteps,
new ScenarioInput(
"brokenDependencyConfirmation",
MESSAGES.demoBrokenDependencyConfirmation,
{ type: "confirm" },
),
new ScenarioAction("brokenDependency", async (state) => {
if (!state.brokenDependencyConfirmation) {
process.exit();
} else {
const client = new SSMClient({});
state.badTableName = `fake-table-${Date.now()}`;
await client.send(
new PutParameterCommand({
Name: NAMES.ssmTableNameKey,
Value: state.badTableName,
Overwrite: true,
Type: "String",
}),
);
}
}),
new ScenarioOutput("testBrokenDependency", (state) =>
MESSAGES.demoTestBrokenDependency.replace(
"${TABLE_NAME}",
state.badTableName,
),
),
...statusSteps,
new ScenarioInput(
"staticResponseConfirmation",
MESSAGES.demoStaticResponseConfirmation,
{ type: "confirm" },
),
new ScenarioAction("staticResponse", async (state) => {
if (!state.staticResponseConfirmation) {
process.exit();
} else {
const client = new SSMClient({});
await client.send(
new PutParameterCommand({
Name: NAMES.ssmFailureResponseKey,
Value: "static",
Overwrite: true,
Type: "String",
}),
);
}
}),
new ScenarioOutput("testStaticResponse", MESSAGES.demoTestStaticResponse),
...statusSteps,
new ScenarioInput(
"badCredentialsConfirmation",
MESSAGES.demoBadCredentialsConfirmation,
{ type: "confirm" },
),
new ScenarioAction("badCredentialsExit", (state) => {
if (!state.badCredentialsConfirmation) {
process.exit();
}
}),
new ScenarioAction("fixDynamoDBName", async () => {
const client = new SSMClient({});
await client.send(
new PutParameterCommand({
Name: NAMES.ssmTableNameKey,
Value: NAMES.tableName,
Overwrite: true,
Type: "String",
}),
);
}),
new ScenarioAction(
"badCredentials",
/**
* @param {{ targetInstance: import('@aws-sdk/client-auto-scaling').Instance }} state
*/
async (state) => {
await createSsmOnlyInstanceProfile();
const autoScalingClient = new AutoScalingClient({});
const { AutoScalingGroups } = await autoScalingClient.send(
new DescribeAutoScalingGroupsCommand({
AutoScalingGroupNames: [NAMES.autoScalingGroupName],
}),
);
state.targetInstance = AutoScalingGroups[0].Instances[0];
const ec2Client = new EC2Client({});
const { IamInstanceProfileAssociations } = await ec2Client.send(
new DescribeIamInstanceProfileAssociationsCommand({
Filters: [
{ Name: "instance-id", Values: [state.targetInstance.InstanceId] },
],
}),
);
state.instanceProfileAssociationId =
IamInstanceProfileAssociations[0].AssociationId;
await retry({ intervalInMs: 1000, maxRetries: 30 }, () =>
ec2Client.send(
new ReplaceIamInstanceProfileAssociationCommand({
AssociationId: state.instanceProfileAssociationId,
IamInstanceProfile: { Name: NAMES.ssmOnlyInstanceProfileName },
}),
),
);
await ec2Client.send(
new RebootInstancesCommand({
InstanceIds: [state.targetInstance.InstanceId],
}),
);
const ssmClient = new SSMClient({});
await retry({ intervalInMs: 20000, maxRetries: 15 }, async () => {
const { InstanceInformationList } = await ssmClient.send(
new DescribeInstanceInformationCommand({}),
);
const instance = InstanceInformationList.find(
(info) => info.InstanceId === state.targetInstance.InstanceId,
);
if (!instance) {
throw new Error("Instance not found.");
}
});
await ssmClient.send(
new SendCommandCommand({
InstanceIds: [state.targetInstance.InstanceId],
DocumentName: "AWS-RunShellScript",
Parameters: { commands: ["cd / && sudo python3 server.py 80"] },
}),
);
},
),
new ScenarioOutput(
"testBadCredentials",
/**
* @param {{ targetInstance: import('@aws-sdk/client-ssm').InstanceInformation}} state
*/
(state) =>
MESSAGES.demoTestBadCredentials.replace(
"${INSTANCE_ID}",
state.targetInstance.InstanceId,
),
),
loadBalancerLoop,
new ScenarioInput(
"deepHealthCheckConfirmation",
MESSAGES.demoDeepHealthCheckConfirmation,
{ type: "confirm" },
),
new ScenarioAction("deepHealthCheckExit", (state) => {
if (!state.deepHealthCheckConfirmation) {
process.exit();
}
}),
new ScenarioAction("deepHealthCheck", async () => {
const client = new SSMClient({});
await client.send(
new PutParameterCommand({
Name: NAMES.ssmHealthCheckKey,
Value: "deep",
Overwrite: true,
Type: "String",
}),
);
}),
new ScenarioOutput("testDeepHealthCheck", MESSAGES.demoTestDeepHealthCheck),
healthCheckLoop,
loadBalancerLoop,
new ScenarioInput(
"killInstanceConfirmation",
/**
* @param {{ targetInstance: import('@aws-sdk/client-ssm').InstanceInformation }} state
*/
(state) =>
MESSAGES.demoKillInstanceConfirmation.replace(
"${INSTANCE_ID}",
state.targetInstance.InstanceId,
),
{ type: "confirm" },
),
new ScenarioAction("killInstanceExit", (state) => {
if (!state.killInstanceConfirmation) {
process.exit();
}
}),
new ScenarioAction(
"killInstance",
/**
* @param {{ targetInstance: import('@aws-sdk/client-ssm').InstanceInformation }} state
*/
async (state) => {
const client = new AutoScalingClient({});
await client.send(
new TerminateInstanceInAutoScalingGroupCommand({
InstanceId: state.targetInstance.InstanceId,
ShouldDecrementDesiredCapacity: false,
}),
);
},
),
new ScenarioOutput("testKillInstance", MESSAGES.demoTestKillInstance),
healthCheckLoop,
loadBalancerLoop,
new ScenarioInput("failOpenConfirmation", MESSAGES.demoFailOpenConfirmation, {
type: "confirm",
}),
new ScenarioAction("failOpenExit", (state) => {
if (!state.failOpenConfirmation) {
process.exit();
}
}),
new ScenarioAction("failOpen", () => {
const client = new SSMClient({});
return client.send(
new PutParameterCommand({
Name: NAMES.ssmTableNameKey,
Value: `fake-table-${Date.now()}`,
Overwrite: true,
Type: "String",
}),
);
}),
new ScenarioOutput("testFailOpen", MESSAGES.demoFailOpenTest),
healthCheckLoop,
loadBalancerLoop,
new ScenarioInput(
"resetTableConfirmation",
MESSAGES.demoResetTableConfirmation,
{ type: "confirm" },
),
new ScenarioAction("resetTableExit", (state) => {
if (!state.resetTableConfirmation) {
process.exit();
}
}),
new ScenarioAction("resetTable", async () => {
const client = new SSMClient({});
await client.send(
new PutParameterCommand({
Name: NAMES.ssmTableNameKey,
Value: NAMES.tableName,
Overwrite: true,
Type: "String",
}),
);
}),
new ScenarioOutput("testResetTable", MESSAGES.demoTestResetTable),
healthCheckLoop,
loadBalancerLoop,
];
async function createSsmOnlyInstanceProfile() {
const iamClient = new IAMClient({});
const { Policy } = await iamClient.send(
new CreatePolicyCommand({
PolicyName: NAMES.ssmOnlyPolicyName,
PolicyDocument: readFileSync(
join(RESOURCES_PATH, "ssm_only_policy.json"),
),
}),
);
await iamClient.send(
new CreateRoleCommand({
RoleName: NAMES.ssmOnlyRoleName,
AssumeRolePolicyDocument: JSON.stringify({
Version: "2012-10-17",
Statement: [
{
Effect: "Allow",
Principal: { Service: "ec2.amazonaws.com" },
Action: "sts:AssumeRole",
},
],
}),
}),
);
await iamClient.send(
new AttachRolePolicyCommand({
RoleName: NAMES.ssmOnlyRoleName,
PolicyArn: Policy.Arn,
}),
);
await iamClient.send(
new AttachRolePolicyCommand({
RoleName: NAMES.ssmOnlyRoleName,
PolicyArn: "arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore",
}),
);
const { InstanceProfile } = await iamClient.send(
new CreateInstanceProfileCommand({
InstanceProfileName: NAMES.ssmOnlyInstanceProfileName,
}),
);
await waitUntilInstanceProfileExists(
{ client: iamClient },
{ InstanceProfileName: NAMES.ssmOnlyInstanceProfileName },
);
await iamClient.send(
new AddRoleToInstanceProfileCommand({
InstanceProfileName: NAMES.ssmOnlyInstanceProfileName,
RoleName: NAMES.ssmOnlyRoleName,
}),
);
return InstanceProfile;
}
```
Create steps to destroy all of the resources.
```
import { unlinkSync } from "node:fs";
import { DynamoDBClient, DeleteTableCommand } from "@aws-sdk/client-dynamodb";
import {
EC2Client,
DeleteKeyPairCommand,
DeleteLaunchTemplateCommand,
RevokeSecurityGroupIngressCommand,
} from "@aws-sdk/client-ec2";
import {
IAMClient,
DeleteInstanceProfileCommand,
RemoveRoleFromInstanceProfileCommand,
DeletePolicyCommand,
DeleteRoleCommand,
DetachRolePolicyCommand,
paginateListPolicies,
} from "@aws-sdk/client-iam";
import {
AutoScalingClient,
DeleteAutoScalingGroupCommand,
TerminateInstanceInAutoScalingGroupCommand,
UpdateAutoScalingGroupCommand,
paginateDescribeAutoScalingGroups,
} from "@aws-sdk/client-auto-scaling";
import {
DeleteLoadBalancerCommand,
DeleteTargetGroupCommand,
DescribeTargetGroupsCommand,
ElasticLoadBalancingV2Client,
} from "@aws-sdk/client-elastic-load-balancing-v2";
import {
ScenarioOutput,
ScenarioInput,
ScenarioAction,
} from "@aws-doc-sdk-examples/lib/scenario/index.js";
import { loadState } from "@aws-doc-sdk-examples/lib/scenario/steps-common.js";
import { retry } from "@aws-doc-sdk-examples/lib/utils/util-timers.js";
import { MESSAGES, NAMES } from "./constants.js";
import { findLoadBalancer } from "./shared.js";
/**
* @type {import('@aws-doc-sdk-examples/lib/scenario.js').Step[]}
*/
export const destroySteps = [
loadState,
new ScenarioInput("destroy", MESSAGES.destroy, { type: "confirm" }),
new ScenarioAction(
"abort",
(state) => state.destroy === false && process.exit(),
),
new ScenarioAction("deleteTable", async (c) => {
try {
const client = new DynamoDBClient({});
await client.send(new DeleteTableCommand({ TableName: NAMES.tableName }));
} catch (e) {
c.deleteTableError = e;
}
}),
new ScenarioOutput("deleteTableResult", (state) => {
if (state.deleteTableError) {
console.error(state.deleteTableError);
return MESSAGES.deleteTableError.replace(
"${TABLE_NAME}",
NAMES.tableName,
);
}
return MESSAGES.deletedTable.replace("${TABLE_NAME}", NAMES.tableName);
}),
new ScenarioAction("deleteKeyPair", async (state) => {
try {
const client = new EC2Client({});
await client.send(
new DeleteKeyPairCommand({ KeyName: NAMES.keyPairName }),
);
unlinkSync(`${NAMES.keyPairName}.pem`);
} catch (e) {
state.deleteKeyPairError = e;
}
}),
new ScenarioOutput("deleteKeyPairResult", (state) => {
if (state.deleteKeyPairError) {
console.error(state.deleteKeyPairError);
return MESSAGES.deleteKeyPairError.replace(
"${KEY_PAIR_NAME}",
NAMES.keyPairName,
);
}
return MESSAGES.deletedKeyPair.replace(
"${KEY_PAIR_NAME}",
NAMES.keyPairName,
);
}),
new ScenarioAction("detachPolicyFromRole", async (state) => {
try {
const client = new IAMClient({});
const policy = await findPolicy(NAMES.instancePolicyName);
if (!policy) {
state.detachPolicyFromRoleError = new Error(
`Policy ${NAMES.instancePolicyName} not found.`,
);
} else {
await client.send(
new DetachRolePolicyCommand({
RoleName: NAMES.instanceRoleName,
PolicyArn: policy.Arn,
}),
);
}
} catch (e) {
state.detachPolicyFromRoleError = e;
}
}),
new ScenarioOutput("detachedPolicyFromRole", (state) => {
if (state.detachPolicyFromRoleError) {
console.error(state.detachPolicyFromRoleError);
return MESSAGES.detachPolicyFromRoleError
.replace("${INSTANCE_POLICY_NAME}", NAMES.instancePolicyName)
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName);
}
return MESSAGES.detachedPolicyFromRole
.replace("${INSTANCE_POLICY_NAME}", NAMES.instancePolicyName)
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName);
}),
new ScenarioAction("deleteInstancePolicy", async (state) => {
const client = new IAMClient({});
const policy = await findPolicy(NAMES.instancePolicyName);
if (!policy) {
state.deletePolicyError = new Error(
`Policy ${NAMES.instancePolicyName} not found.`,
);
} else {
return client.send(
new DeletePolicyCommand({
PolicyArn: policy.Arn,
}),
);
}
}),
new ScenarioOutput("deletePolicyResult", (state) => {
if (state.deletePolicyError) {
console.error(state.deletePolicyError);
return MESSAGES.deletePolicyError.replace(
"${INSTANCE_POLICY_NAME}",
NAMES.instancePolicyName,
);
}
return MESSAGES.deletedPolicy.replace(
"${INSTANCE_POLICY_NAME}",
NAMES.instancePolicyName,
);
}),
new ScenarioAction("removeRoleFromInstanceProfile", async (state) => {
try {
const client = new IAMClient({});
await client.send(
new RemoveRoleFromInstanceProfileCommand({
RoleName: NAMES.instanceRoleName,
InstanceProfileName: NAMES.instanceProfileName,
}),
);
} catch (e) {
state.removeRoleFromInstanceProfileError = e;
}
}),
new ScenarioOutput("removeRoleFromInstanceProfileResult", (state) => {
if (state.removeRoleFromInstanceProfile) {
console.error(state.removeRoleFromInstanceProfileError);
return MESSAGES.removeRoleFromInstanceProfileError
.replace("${INSTANCE_PROFILE_NAME}", NAMES.instanceProfileName)
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName);
}
return MESSAGES.removedRoleFromInstanceProfile
.replace("${INSTANCE_PROFILE_NAME}", NAMES.instanceProfileName)
.replace("${INSTANCE_ROLE_NAME}", NAMES.instanceRoleName);
}),
new ScenarioAction("deleteInstanceRole", async (state) => {
try {
const client = new IAMClient({});
await client.send(
new DeleteRoleCommand({
RoleName: NAMES.instanceRoleName,
}),
);
} catch (e) {
state.deleteInstanceRoleError = e;
}
}),
new ScenarioOutput("deleteInstanceRoleResult", (state) => {
if (state.deleteInstanceRoleError) {
console.error(state.deleteInstanceRoleError);
return MESSAGES.deleteInstanceRoleError.replace(
"${INSTANCE_ROLE_NAME}",
NAMES.instanceRoleName,
);
}
return MESSAGES.deletedInstanceRole.replace(
"${INSTANCE_ROLE_NAME}",
NAMES.instanceRoleName,
);
}),
new ScenarioAction("deleteInstanceProfile", async (state) => {
try {
const client = new IAMClient({});
await client.send(
new DeleteInstanceProfileCommand({
InstanceProfileName: NAMES.instanceProfileName,
}),
);
} catch (e) {
state.deleteInstanceProfileError = e;
}
}),
new ScenarioOutput("deleteInstanceProfileResult", (state) => {
if (state.deleteInstanceProfileError) {
console.error(state.deleteInstanceProfileError);
return MESSAGES.deleteInstanceProfileError.replace(
"${INSTANCE_PROFILE_NAME}",
NAMES.instanceProfileName,
);
}
return MESSAGES.deletedInstanceProfile.replace(
"${INSTANCE_PROFILE_NAME}",
NAMES.instanceProfileName,
);
}),
new ScenarioAction("deleteAutoScalingGroup", async (state) => {
try {
await terminateGroupInstances(NAMES.autoScalingGroupName);
await retry({ intervalInMs: 60000, maxRetries: 60 }, async () => {
await deleteAutoScalingGroup(NAMES.autoScalingGroupName);
});
} catch (e) {
state.deleteAutoScalingGroupError = e;
}
}),
new ScenarioOutput("deleteAutoScalingGroupResult", (state) => {
if (state.deleteAutoScalingGroupError) {
console.error(state.deleteAutoScalingGroupError);
return MESSAGES.deleteAutoScalingGroupError.replace(
"${AUTO_SCALING_GROUP_NAME}",
NAMES.autoScalingGroupName,
);
}
return MESSAGES.deletedAutoScalingGroup.replace(
"${AUTO_SCALING_GROUP_NAME}",
NAMES.autoScalingGroupName,
);
}),
new ScenarioAction("deleteLaunchTemplate", async (state) => {
const client = new EC2Client({});
try {
await client.send(
new DeleteLaunchTemplateCommand({
LaunchTemplateName: NAMES.launchTemplateName,
}),
);
} catch (e) {
state.deleteLaunchTemplateError = e;
}
}),
new ScenarioOutput("deleteLaunchTemplateResult", (state) => {
if (state.deleteLaunchTemplateError) {
console.error(state.deleteLaunchTemplateError);
return MESSAGES.deleteLaunchTemplateError.replace(
"${LAUNCH_TEMPLATE_NAME}",
NAMES.launchTemplateName,
);
}
return MESSAGES.deletedLaunchTemplate.replace(
"${LAUNCH_TEMPLATE_NAME}",
NAMES.launchTemplateName,
);
}),
new ScenarioAction("deleteLoadBalancer", async (state) => {
try {
const client = new ElasticLoadBalancingV2Client({});
const loadBalancer = await findLoadBalancer(NAMES.loadBalancerName);
await client.send(
new DeleteLoadBalancerCommand({
LoadBalancerArn: loadBalancer.LoadBalancerArn,
}),
);
await retry({ intervalInMs: 1000, maxRetries: 60 }, async () => {
const lb = await findLoadBalancer(NAMES.loadBalancerName);
if (lb) {
throw new Error("Load balancer still exists.");
}
});
} catch (e) {
state.deleteLoadBalancerError = e;
}
}),
new ScenarioOutput("deleteLoadBalancerResult", (state) => {
if (state.deleteLoadBalancerError) {
console.error(state.deleteLoadBalancerError);
return MESSAGES.deleteLoadBalancerError.replace(
"${LB_NAME}",
NAMES.loadBalancerName,
);
}
return MESSAGES.deletedLoadBalancer.replace(
"${LB_NAME}",
NAMES.loadBalancerName,
);
}),
new ScenarioAction("deleteLoadBalancerTargetGroup", async (state) => {
const client = new ElasticLoadBalancingV2Client({});
try {
const { TargetGroups } = await client.send(
new DescribeTargetGroupsCommand({
Names: [NAMES.loadBalancerTargetGroupName],
}),
);
await retry({ intervalInMs: 1000, maxRetries: 30 }, () =>
client.send(
new DeleteTargetGroupCommand({
TargetGroupArn: TargetGroups[0].TargetGroupArn,
}),
),
);
} catch (e) {
state.deleteLoadBalancerTargetGroupError = e;
}
}),
new ScenarioOutput("deleteLoadBalancerTargetGroupResult", (state) => {
if (state.deleteLoadBalancerTargetGroupError) {
console.error(state.deleteLoadBalancerTargetGroupError);
return MESSAGES.deleteLoadBalancerTargetGroupError.replace(
"${TARGET_GROUP_NAME}",
NAMES.loadBalancerTargetGroupName,
);
}
return MESSAGES.deletedLoadBalancerTargetGroup.replace(
"${TARGET_GROUP_NAME}",
NAMES.loadBalancerTargetGroupName,
);
}),
new ScenarioAction("detachSsmOnlyRoleFromProfile", async (state) => {
try {
const client = new IAMClient({});
await client.send(
new RemoveRoleFromInstanceProfileCommand({
InstanceProfileName: NAMES.ssmOnlyInstanceProfileName,
RoleName: NAMES.ssmOnlyRoleName,
}),
);
} catch (e) {
state.detachSsmOnlyRoleFromProfileError = e;
}
}),
new ScenarioOutput("detachSsmOnlyRoleFromProfileResult", (state) => {
if (state.detachSsmOnlyRoleFromProfileError) {
console.error(state.detachSsmOnlyRoleFromProfileError);
return MESSAGES.detachSsmOnlyRoleFromProfileError
.replace("${ROLE_NAME}", NAMES.ssmOnlyRoleName)
.replace("${PROFILE_NAME}", NAMES.ssmOnlyInstanceProfileName);
}
return MESSAGES.detachedSsmOnlyRoleFromProfile
.replace("${ROLE_NAME}", NAMES.ssmOnlyRoleName)
.replace("${PROFILE_NAME}", NAMES.ssmOnlyInstanceProfileName);
}),
new ScenarioAction("detachSsmOnlyCustomRolePolicy", async (state) => {
try {
const iamClient = new IAMClient({});
const ssmOnlyPolicy = await findPolicy(NAMES.ssmOnlyPolicyName);
await iamClient.send(
new DetachRolePolicyCommand({
RoleName: NAMES.ssmOnlyRoleName,
PolicyArn: ssmOnlyPolicy.Arn,
}),
);
} catch (e) {
state.detachSsmOnlyCustomRolePolicyError = e;
}
}),
new ScenarioOutput("detachSsmOnlyCustomRolePolicyResult", (state) => {
if (state.detachSsmOnlyCustomRolePolicyError) {
console.error(state.detachSsmOnlyCustomRolePolicyError);
return MESSAGES.detachSsmOnlyCustomRolePolicyError
.replace("${ROLE_NAME}", NAMES.ssmOnlyRoleName)
.replace("${POLICY_NAME}", NAMES.ssmOnlyPolicyName);
}
return MESSAGES.detachedSsmOnlyCustomRolePolicy
.replace("${ROLE_NAME}", NAMES.ssmOnlyRoleName)
.replace("${POLICY_NAME}", NAMES.ssmOnlyPolicyName);
}),
new ScenarioAction("detachSsmOnlyAWSRolePolicy", async (state) => {
try {
const iamClient = new IAMClient({});
await iamClient.send(
new DetachRolePolicyCommand({
RoleName: NAMES.ssmOnlyRoleName,
PolicyArn: "arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore",
}),
);
} catch (e) {
state.detachSsmOnlyAWSRolePolicyError = e;
}
}),
new ScenarioOutput("detachSsmOnlyAWSRolePolicyResult", (state) => {
if (state.detachSsmOnlyAWSRolePolicyError) {
console.error(state.detachSsmOnlyAWSRolePolicyError);
return MESSAGES.detachSsmOnlyAWSRolePolicyError
.replace("${ROLE_NAME}", NAMES.ssmOnlyRoleName)
.replace("${POLICY_NAME}", "AmazonSSMManagedInstanceCore");
}
return MESSAGES.detachedSsmOnlyAWSRolePolicy
.replace("${ROLE_NAME}", NAMES.ssmOnlyRoleName)
.replace("${POLICY_NAME}", "AmazonSSMManagedInstanceCore");
}),
new ScenarioAction("deleteSsmOnlyInstanceProfile", async (state) => {
try {
const iamClient = new IAMClient({});
await iamClient.send(
new DeleteInstanceProfileCommand({
InstanceProfileName: NAMES.ssmOnlyInstanceProfileName,
}),
);
} catch (e) {
state.deleteSsmOnlyInstanceProfileError = e;
}
}),
new ScenarioOutput("deleteSsmOnlyInstanceProfileResult", (state) => {
if (state.deleteSsmOnlyInstanceProfileError) {
console.error(state.deleteSsmOnlyInstanceProfileError);
return MESSAGES.deleteSsmOnlyInstanceProfileError.replace(
"${INSTANCE_PROFILE_NAME}",
NAMES.ssmOnlyInstanceProfileName,
);
}
return MESSAGES.deletedSsmOnlyInstanceProfile.replace(
"${INSTANCE_PROFILE_NAME}",
NAMES.ssmOnlyInstanceProfileName,
);
}),
new ScenarioAction("deleteSsmOnlyPolicy", async (state) => {
try {
const iamClient = new IAMClient({});
const ssmOnlyPolicy = await findPolicy(NAMES.ssmOnlyPolicyName);
await iamClient.send(
new DeletePolicyCommand({
PolicyArn: ssmOnlyPolicy.Arn,
}),
);
} catch (e) {
state.deleteSsmOnlyPolicyError = e;
}
}),
new ScenarioOutput("deleteSsmOnlyPolicyResult", (state) => {
if (state.deleteSsmOnlyPolicyError) {
console.error(state.deleteSsmOnlyPolicyError);
return MESSAGES.deleteSsmOnlyPolicyError.replace(
"${POLICY_NAME}",
NAMES.ssmOnlyPolicyName,
);
}
return MESSAGES.deletedSsmOnlyPolicy.replace(
"${POLICY_NAME}",
NAMES.ssmOnlyPolicyName,
);
}),
new ScenarioAction("deleteSsmOnlyRole", async (state) => {
try {
const iamClient = new IAMClient({});
await iamClient.send(
new DeleteRoleCommand({
RoleName: NAMES.ssmOnlyRoleName,
}),
);
} catch (e) {
state.deleteSsmOnlyRoleError = e;
}
}),
new ScenarioOutput("deleteSsmOnlyRoleResult", (state) => {
if (state.deleteSsmOnlyRoleError) {
console.error(state.deleteSsmOnlyRoleError);
return MESSAGES.deleteSsmOnlyRoleError.replace(
"${ROLE_NAME}",
NAMES.ssmOnlyRoleName,
);
}
return MESSAGES.deletedSsmOnlyRole.replace(
"${ROLE_NAME}",
NAMES.ssmOnlyRoleName,
);
}),
new ScenarioAction(
"revokeSecurityGroupIngress",
async (
/** @type {{ myIp: string, defaultSecurityGroup: { GroupId: string } }} */ state,
) => {
const ec2Client = new EC2Client({});
try {
await ec2Client.send(
new RevokeSecurityGroupIngressCommand({
GroupId: state.defaultSecurityGroup.GroupId,
CidrIp: `${state.myIp}/32`,
FromPort: 80,
ToPort: 80,
IpProtocol: "tcp",
}),
);
} catch (e) {
state.revokeSecurityGroupIngressError = e;
}
},
),
new ScenarioOutput("revokeSecurityGroupIngressResult", (state) => {
if (state.revokeSecurityGroupIngressError) {
console.error(state.revokeSecurityGroupIngressError);
return MESSAGES.revokeSecurityGroupIngressError.replace(
"${IP}",
state.myIp,
);
}
return MESSAGES.revokedSecurityGroupIngress.replace("${IP}", state.myIp);
}),
];
/**
* @param {string} policyName
*/
async function findPolicy(policyName) {
const client = new IAMClient({});
const paginatedPolicies = paginateListPolicies({ client }, {});
for await (const page of paginatedPolicies) {
const policy = page.Policies.find((p) => p.PolicyName === policyName);
if (policy) {
return policy;
}
}
}
/**
* @param {string} groupName
*/
async function deleteAutoScalingGroup(groupName) {
const client = new AutoScalingClient({});
try {
await client.send(
new DeleteAutoScalingGroupCommand({
AutoScalingGroupName: groupName,
}),
);
} catch (err) {
if (!(err instanceof Error)) {
throw err;
}
console.log(err.name);
throw err;
}
}
/**
* @param {string} groupName
*/
async function terminateGroupInstances(groupName) {
const autoScalingClient = new AutoScalingClient({});
const group = await findAutoScalingGroup(groupName);
await autoScalingClient.send(
new UpdateAutoScalingGroupCommand({
AutoScalingGroupName: group.AutoScalingGroupName,
MinSize: 0,
}),
);
for (const i of group.Instances) {
await retry({ intervalInMs: 1000, maxRetries: 30 }, () =>
autoScalingClient.send(
new TerminateInstanceInAutoScalingGroupCommand({
InstanceId: i.InstanceId,
ShouldDecrementDesiredCapacity: true,
}),
),
);
}
}
async function findAutoScalingGroup(groupName) {
const client = new AutoScalingClient({});
const paginatedGroups = paginateDescribeAutoScalingGroups({ client }, {});
for await (const page of paginatedGroups) {
const group = page.AutoScalingGroups.find(
(g) => g.AutoScalingGroupName === groupName,
);
if (group) {
return group;
}
}
throw new Error(`Auto scaling group ${groupName} not found.`);
}
```
+ For API details, see the following topics in *AWS SDK for JavaScript API Reference*.
+ [AttachLoadBalancerTargetGroups](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/auto-scaling/command/AttachLoadBalancerTargetGroupsCommand)
+ [CreateAutoScalingGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/auto-scaling/command/CreateAutoScalingGroupCommand)
+ [CreateInstanceProfile](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/iam/command/CreateInstanceProfileCommand)
+ [CreateLaunchTemplate](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/CreateLaunchTemplateCommand)
+ [CreateListener](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/CreateListenerCommand)
+ [CreateLoadBalancer](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/CreateLoadBalancerCommand)
+ [CreateTargetGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/CreateTargetGroupCommand)
+ [DeleteAutoScalingGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/auto-scaling/command/DeleteAutoScalingGroupCommand)
+ [DeleteInstanceProfile](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/iam/command/DeleteInstanceProfileCommand)
+ [DeleteLaunchTemplate](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/DeleteLaunchTemplateCommand)
+ [DeleteLoadBalancer](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DeleteLoadBalancerCommand)
+ [DeleteTargetGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DeleteTargetGroupCommand)
+ [DescribeAutoScalingGroups](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/auto-scaling/command/DescribeAutoScalingGroupsCommand)
+ [DescribeAvailabilityZones](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/DescribeAvailabilityZonesCommand)
+ [DescribeIamInstanceProfileAssociations](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/DescribeIamInstanceProfileAssociationsCommand)
+ [DescribeInstances](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/DescribeInstancesCommand)
+ [DescribeLoadBalancers](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DescribeLoadBalancersCommand)
+ [DescribeSubnets](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/DescribeSubnetsCommand)
+ [DescribeTargetGroups](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DescribeTargetGroupsCommand)
+ [DescribeTargetHealth](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/elastic-load-balancing-v2/command/DescribeTargetHealthCommand)
+ [DescribeVpcs](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/DescribeVpcsCommand)
+ [RebootInstances](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/RebootInstancesCommand)
+ [ReplaceIamInstanceProfileAssociation](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/ec2/command/ReplaceIamInstanceProfileAssociationCommand)
+ [TerminateInstanceInAutoScalingGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/auto-scaling/command/TerminateInstanceInAutoScalingGroupCommand)
+ [UpdateAutoScalingGroup](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/auto-scaling/command/UpdateAutoScalingGroupCommand)
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/resilient_service#code-examples).
Run the interactive scenario at a command prompt.
```
class Runner:
"""
Manages the deployment, demonstration, and destruction of resources for the resilient service.
"""
def __init__(
self,
resource_path: str,
recommendation: RecommendationService,
autoscaler: AutoScalingWrapper,
loadbalancer: ElasticLoadBalancerWrapper,
param_helper: ParameterHelper,
):
"""
Initializes the Runner class with the necessary parameters.
:param resource_path: The path to resource files used by this example, such as IAM policies and instance scripts.
:param recommendation: An instance of the RecommendationService class.
:param autoscaler: An instance of the AutoScaler class.
:param loadbalancer: An instance of the LoadBalancer class.
:param param_helper: An instance of the ParameterHelper class.
"""
self.resource_path = resource_path
self.recommendation = recommendation
self.autoscaler = autoscaler
self.loadbalancer = loadbalancer
self.param_helper = param_helper
self.protocol = "HTTP"
self.port = 80
self.ssh_port = 22
prefix = "doc-example-resilience"
self.target_group_name = f"{prefix}-tg"
self.load_balancer_name = f"{prefix}-lb"
def deploy(self) -> None:
"""
Deploys the resources required for the resilient service, including the DynamoDB table,
EC2 instances, Auto Scaling group, and load balancer.
"""
recommendations_path = f"{self.resource_path}/recommendations.json"
startup_script = f"{self.resource_path}/server_startup_script.sh"
instance_policy = f"{self.resource_path}/instance_policy.json"
logging.info("Starting deployment of resources for the resilient service.")
logging.info(
"Creating and populating DynamoDB table '%s'.",
self.recommendation.table_name,
)
self.recommendation.create()
self.recommendation.populate(recommendations_path)
logging.info(
"Creating an EC2 launch template with the startup script '%s'.",
startup_script,
)
self.autoscaler.create_template(startup_script, instance_policy)
logging.info(
"Creating an EC2 Auto Scaling group across multiple Availability Zones."
)
zones = self.autoscaler.create_autoscaling_group(3)
logging.info("Creating variables that control the flow of the demo.")
self.param_helper.reset()
logging.info("Creating Elastic Load Balancing target group and load balancer.")
vpc = self.autoscaler.get_default_vpc()
subnets = self.autoscaler.get_subnets(vpc["VpcId"], zones)
target_group = self.loadbalancer.create_target_group(
self.target_group_name, self.protocol, self.port, vpc["VpcId"]
)
self.loadbalancer.create_load_balancer(
self.load_balancer_name, [subnet["SubnetId"] for subnet in subnets]
)
self.loadbalancer.create_listener(self.load_balancer_name, target_group)
self.autoscaler.attach_load_balancer_target_group(target_group)
logging.info("Verifying access to the load balancer endpoint.")
endpoint = self.loadbalancer.get_endpoint(self.load_balancer_name)
lb_success = self.loadbalancer.verify_load_balancer_endpoint(endpoint)
current_ip_address = requests.get("http://checkip.amazonaws.com").text.strip()
if not lb_success:
logging.warning(
"Couldn't connect to the load balancer. Verifying that the port is open..."
)
sec_group, port_is_open = self.autoscaler.verify_inbound_port(
vpc, self.port, current_ip_address
)
sec_group, ssh_port_is_open = self.autoscaler.verify_inbound_port(
vpc, self.ssh_port, current_ip_address
)
if not port_is_open:
logging.warning(
"The default security group for your VPC must allow access from this computer."
)
if q.ask(
f"Do you want to add a rule to security group {sec_group['GroupId']} to allow\n"
f"inbound traffic on port {self.port} from your computer's IP address of {current_ip_address}? (y/n) ",
q.is_yesno,
):
self.autoscaler.open_inbound_port(
sec_group["GroupId"], self.port, current_ip_address
)
if not ssh_port_is_open:
if q.ask(
f"Do you want to add a rule to security group {sec_group['GroupId']} to allow\n"
f"inbound SSH traffic on port {self.ssh_port} for debugging from your computer's IP address of {current_ip_address}? (y/n) ",
q.is_yesno,
):
self.autoscaler.open_inbound_port(
sec_group["GroupId"], self.ssh_port, current_ip_address
)
lb_success = self.loadbalancer.verify_load_balancer_endpoint(endpoint)
if lb_success:
logging.info(
"Load balancer is ready. Access it at: http://%s", current_ip_address
)
else:
logging.error(
"Couldn't get a successful response from the load balancer endpoint. Please verify your VPC and security group settings."
)
def demo_choices(self) -> None:
"""
Presents choices for interacting with the deployed service, such as sending requests to
the load balancer or checking the health of the targets.
"""
actions = [
"Send a GET request to the load balancer endpoint.",
"Check the health of load balancer targets.",
"Go to the next part of the demo.",
]
choice = 0
while choice != 2:
logging.info("Choose an action to interact with the service.")
choice = q.choose("Which action would you like to take? ", actions)
if choice == 0:
logging.info("Sending a GET request to the load balancer endpoint.")
endpoint = self.loadbalancer.get_endpoint(self.load_balancer_name)
logging.info("GET http://%s", endpoint)
response = requests.get(f"http://{endpoint}")
logging.info("Response: %s", response.status_code)
if response.headers.get("content-type") == "application/json":
pp(response.json())
elif choice == 1:
logging.info("Checking the health of load balancer targets.")
health = self.loadbalancer.check_target_health(self.target_group_name)
for target in health:
state = target["TargetHealth"]["State"]
logging.info(
"Target %s on port %d is %s",
target["Target"]["Id"],
target["Target"]["Port"],
state,
)
if state != "healthy":
logging.warning(
"%s: %s",
target["TargetHealth"]["Reason"],
target["TargetHealth"]["Description"],
)
logging.info(
"Note that it can take a minute or two for the health check to update."
)
elif choice == 2:
logging.info("Proceeding to the next part of the demo.")
def demo(self) -> None:
"""
Runs the demonstration, showing how the service responds to different failure scenarios
and how a resilient architecture can keep the service running.
"""
ssm_only_policy = f"{self.resource_path}/ssm_only_policy.json"
logging.info("Resetting parameters to starting values for the demo.")
self.param_helper.reset()
logging.info(
"Starting demonstration of the service's resilience under various failure conditions."
)
self.demo_choices()
logging.info(
"Simulating failure by changing the Systems Manager parameter to a non-existent table."
)
self.param_helper.put(self.param_helper.table, "this-is-not-a-table")
logging.info("Sending GET requests will now return failure codes.")
self.demo_choices()
logging.info("Switching to static response mode to mitigate failure.")
self.param_helper.put(self.param_helper.failure_response, "static")
logging.info("Sending GET requests will now return static responses.")
self.demo_choices()
logging.info("Restoring normal operation of the recommendation service.")
self.param_helper.put(self.param_helper.table, self.recommendation.table_name)
logging.info(
"Introducing a failure by assigning bad credentials to one of the instances."
)
self.autoscaler.create_instance_profile(
ssm_only_policy,
self.autoscaler.bad_creds_policy_name,
self.autoscaler.bad_creds_role_name,
self.autoscaler.bad_creds_profile_name,
["AmazonSSMManagedInstanceCore"],
)
instances = self.autoscaler.get_instances()
bad_instance_id = instances[0]
instance_profile = self.autoscaler.get_instance_profile(bad_instance_id)
logging.info(
"Replacing instance profile with bad credentials for instance %s.",
bad_instance_id,
)
self.autoscaler.replace_instance_profile(
bad_instance_id,
self.autoscaler.bad_creds_profile_name,
instance_profile["AssociationId"],
)
logging.info(
"Sending GET requests may return either a valid recommendation or a static response."
)
self.demo_choices()
logging.info("Implementing deep health checks to detect unhealthy instances.")
self.param_helper.put(self.param_helper.health_check, "deep")
logging.info("Checking the health of the load balancer targets.")
self.demo_choices()
logging.info(
"Terminating the unhealthy instance to let the auto scaler replace it."
)
self.autoscaler.terminate_instance(bad_instance_id)
logging.info("The service remains resilient during instance replacement.")
self.demo_choices()
logging.info("Simulating a complete failure of the recommendation service.")
self.param_helper.put(self.param_helper.table, "this-is-not-a-table")
logging.info(
"All instances will report as unhealthy, but the service will still return static responses."
)
self.demo_choices()
self.param_helper.reset()
def destroy(self, automation=False) -> None:
"""
Destroys all resources created for the demo, including the load balancer, Auto Scaling group,
EC2 instances, and DynamoDB table.
"""
logging.info(
"This concludes the demo. Preparing to clean up all AWS resources created during the demo."
)
if automation:
cleanup = True
else:
cleanup = q.ask(
"Do you want to clean up all demo resources? (y/n) ", q.is_yesno
)
if cleanup:
logging.info("Deleting load balancer and related resources.")
self.loadbalancer.delete_load_balancer(self.load_balancer_name)
self.loadbalancer.delete_target_group(self.target_group_name)
self.autoscaler.delete_autoscaling_group(self.autoscaler.group_name)
self.autoscaler.delete_key_pair()
self.autoscaler.delete_template()
self.autoscaler.delete_instance_profile(
self.autoscaler.bad_creds_profile_name,
self.autoscaler.bad_creds_role_name,
)
logging.info("Deleting DynamoDB table and other resources.")
self.recommendation.destroy()
else:
logging.warning(
"Resources have not been deleted. Ensure you clean them up manually to avoid unexpected charges."
)
def main() -> None:
"""
Main function to parse arguments and run the appropriate actions for the demo.
"""
parser = argparse.ArgumentParser()
parser.add_argument(
"--action",
required=True,
choices=["all", "deploy", "demo", "destroy"],
help="The action to take for the demo. When 'all' is specified, resources are\n"
"deployed, the demo is run, and resources are destroyed.",
)
parser.add_argument(
"--resource_path",
default="../../../scenarios/features/resilient_service/resources",
help="The path to resource files used by this example, such as IAM policies and\n"
"instance scripts.",
)
args = parser.parse_args()
logging.info("Starting the Resilient Service demo.")
prefix = "doc-example-resilience"
# Service Clients
ddb_client = boto3.client("dynamodb")
elb_client = boto3.client("elbv2")
autoscaling_client = boto3.client("autoscaling")
ec2_client = boto3.client("ec2")
ssm_client = boto3.client("ssm")
iam_client = boto3.client("iam")
# Wrapper instantiations
recommendation = RecommendationService(
"doc-example-recommendation-service", ddb_client
)
autoscaling_wrapper = AutoScalingWrapper(
prefix,
"t3.micro",
"/aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2",
autoscaling_client,
ec2_client,
ssm_client,
iam_client,
)
elb_wrapper = ElasticLoadBalancerWrapper(elb_client)
param_helper = ParameterHelper(recommendation.table_name, ssm_client)
# Demo invocation
runner = Runner(
args.resource_path,
recommendation,
autoscaling_wrapper,
elb_wrapper,
param_helper,
)
actions = [args.action] if args.action != "all" else ["deploy", "demo", "destroy"]
for action in actions:
if action == "deploy":
runner.deploy()
elif action == "demo":
runner.demo()
elif action == "destroy":
runner.destroy()
logging.info("Demo completed successfully.")
if __name__ == "__main__":
logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")
main()
```
Create a class that wraps Auto Scaling and Amazon EC2 actions.
```
class AutoScalingWrapper:
"""
Encapsulates Amazon EC2 Auto Scaling and EC2 management actions.
"""
def __init__(
self,
resource_prefix: str,
inst_type: str,
ami_param: str,
autoscaling_client: boto3.client,
ec2_client: boto3.client,
ssm_client: boto3.client,
iam_client: boto3.client,
):
"""
Initializes the AutoScaler class with the necessary parameters.
:param resource_prefix: The prefix for naming AWS resources that are created by this class.
:param inst_type: The type of EC2 instance to create, such as t3.micro.
:param ami_param: The Systems Manager parameter used to look up the AMI that is created.
:param autoscaling_client: A Boto3 EC2 Auto Scaling client.
:param ec2_client: A Boto3 EC2 client.
:param ssm_client: A Boto3 Systems Manager client.
:param iam_client: A Boto3 IAM client.
"""
self.inst_type = inst_type
self.ami_param = ami_param
self.autoscaling_client = autoscaling_client
self.ec2_client = ec2_client
self.ssm_client = ssm_client
self.iam_client = iam_client
sts_client = boto3.client("sts")
self.account_id = sts_client.get_caller_identity()["Account"]
self.key_pair_name = f"{resource_prefix}-key-pair"
self.launch_template_name = f"{resource_prefix}-template-"
self.group_name = f"{resource_prefix}-group"
# Happy path
self.instance_policy_name = f"{resource_prefix}-pol"
self.instance_role_name = f"{resource_prefix}-role"
self.instance_profile_name = f"{resource_prefix}-prof"
# Failure mode
self.bad_creds_policy_name = f"{resource_prefix}-bc-pol"
self.bad_creds_role_name = f"{resource_prefix}-bc-role"
self.bad_creds_profile_name = f"{resource_prefix}-bc-prof"
def create_policy(self, policy_file: str, policy_name: str) -> str:
"""
Creates a new IAM policy or retrieves the ARN of an existing policy.
:param policy_file: The path to a JSON file that contains the policy definition.
:param policy_name: The name to give the created policy.
:return: The ARN of the created or existing policy.
"""
with open(policy_file) as file:
policy_doc = file.read()
try:
response = self.iam_client.create_policy(
PolicyName=policy_name, PolicyDocument=policy_doc
)
policy_arn = response["Policy"]["Arn"]
log.info(f"Policy '{policy_name}' created successfully. ARN: {policy_arn}")
return policy_arn
except ClientError as err:
if err.response["Error"]["Code"] == "EntityAlreadyExists":
# If the policy already exists, get its ARN
response = self.iam_client.get_policy(
PolicyArn=f"arn:aws:iam::{self.account_id}:policy/{policy_name}"
)
policy_arn = response["Policy"]["Arn"]
log.info(f"Policy '{policy_name}' already exists. ARN: {policy_arn}")
return policy_arn
log.error(f"Full error:\n\t{err}")
def create_role(self, role_name: str, assume_role_doc: dict) -> str:
"""
Creates a new IAM role or retrieves the ARN of an existing role.
:param role_name: The name to give the created role.
:param assume_role_doc: The assume role policy document that specifies which
entities can assume the role.
:return: The ARN of the created or existing role.
"""
try:
response = self.iam_client.create_role(
RoleName=role_name, AssumeRolePolicyDocument=json.dumps(assume_role_doc)
)
role_arn = response["Role"]["Arn"]
log.info(f"Role '{role_name}' created successfully. ARN: {role_arn}")
return role_arn
except ClientError as err:
if err.response["Error"]["Code"] == "EntityAlreadyExists":
# If the role already exists, get its ARN
response = self.iam_client.get_role(RoleName=role_name)
role_arn = response["Role"]["Arn"]
log.info(f"Role '{role_name}' already exists. ARN: {role_arn}")
return role_arn
log.error(f"Full error:\n\t{err}")
def attach_policy(
self,
role_name: str,
policy_arn: str,
aws_managed_policies: Tuple[str, ...] = (),
) -> None:
"""
Attaches an IAM policy to a role and optionally attaches additional AWS-managed policies.
:param role_name: The name of the role to attach the policy to.
:param policy_arn: The ARN of the policy to attach.
:param aws_managed_policies: A tuple of AWS-managed policy names to attach to the role.
"""
try:
self.iam_client.attach_role_policy(RoleName=role_name, PolicyArn=policy_arn)
for aws_policy in aws_managed_policies:
self.iam_client.attach_role_policy(
RoleName=role_name,
PolicyArn=f"arn:aws:iam::aws:policy/{aws_policy}",
)
log.info(f"Attached policy {policy_arn} to role {role_name}.")
except ClientError as err:
log.error(f"Failed to attach policy {policy_arn} to role {role_name}.")
log.error(f"Full error:\n\t{err}")
def create_instance_profile(
self,
policy_file: str,
policy_name: str,
role_name: str,
profile_name: str,
aws_managed_policies: Tuple[str, ...] = (),
) -> str:
"""
Creates a policy, role, and profile that is associated with instances created by
this class. An instance's associated profile defines a role that is assumed by the
instance. The role has attached policies that specify the AWS permissions granted to
clients that run on the instance.
:param policy_file: The name of a JSON file that contains the policy definition to
create and attach to the role.
:param policy_name: The name to give the created policy.
:param role_name: The name to give the created role.
:param profile_name: The name to the created profile.
:param aws_managed_policies: Additional AWS-managed policies that are attached to
the role, such as AmazonSSMManagedInstanceCore to grant
use of Systems Manager to send commands to the instance.
:return: The ARN of the profile that is created.
"""
assume_role_doc = {
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {"Service": "ec2.amazonaws.com"},
"Action": "sts:AssumeRole",
}
],
}
policy_arn = self.create_policy(policy_file, policy_name)
self.create_role(role_name, assume_role_doc)
self.attach_policy(role_name, policy_arn, aws_managed_policies)
try:
profile_response = self.iam_client.create_instance_profile(
InstanceProfileName=profile_name
)
waiter = self.iam_client.get_waiter("instance_profile_exists")
waiter.wait(InstanceProfileName=profile_name)
time.sleep(10) # wait a little longer
profile_arn = profile_response["InstanceProfile"]["Arn"]
self.iam_client.add_role_to_instance_profile(
InstanceProfileName=profile_name, RoleName=role_name
)
log.info("Created profile %s and added role %s.", profile_name, role_name)
except ClientError as err:
if err.response["Error"]["Code"] == "EntityAlreadyExists":
prof_response = self.iam_client.get_instance_profile(
InstanceProfileName=profile_name
)
profile_arn = prof_response["InstanceProfile"]["Arn"]
log.info(
"Instance profile %s already exists, nothing to do.", profile_name
)
log.error(f"Full error:\n\t{err}")
return profile_arn
def get_instance_profile(self, instance_id: str) -> Dict[str, Any]:
"""
Gets data about the profile associated with an instance.
:param instance_id: The ID of the instance to look up.
:return: The profile data.
"""
try:
response = self.ec2_client.describe_iam_instance_profile_associations(
Filters=[{"Name": "instance-id", "Values": [instance_id]}]
)
if not response["IamInstanceProfileAssociations"]:
log.info(f"No instance profile found for instance {instance_id}.")
profile_data = response["IamInstanceProfileAssociations"][0]
log.info(f"Retrieved instance profile for instance {instance_id}.")
return profile_data
except ClientError as err:
log.error(
f"Failed to retrieve instance profile for instance {instance_id}."
)
error_code = err.response["Error"]["Code"]
if error_code == "InvalidInstanceID.NotFound":
log.error(f"The instance ID '{instance_id}' does not exist.")
log.error(f"Full error:\n\t{err}")
def replace_instance_profile(
self,
instance_id: str,
new_instance_profile_name: str,
profile_association_id: str,
) -> None:
"""
Replaces the profile associated with a running instance. After the profile is
replaced, the instance is rebooted to ensure that it uses the new profile. When
the instance is ready, Systems Manager is used to restart the Python web server.
:param instance_id: The ID of the instance to restart.
:param new_instance_profile_name: The name of the new profile to associate with
the specified instance.
:param profile_association_id: The ID of the existing profile association for the
instance.
"""
try:
self.ec2_client.replace_iam_instance_profile_association(
IamInstanceProfile={"Name": new_instance_profile_name},
AssociationId=profile_association_id,
)
log.info(
"Replaced instance profile for association %s with profile %s.",
profile_association_id,
new_instance_profile_name,
)
time.sleep(5)
self.ec2_client.reboot_instances(InstanceIds=[instance_id])
log.info("Rebooting instance %s.", instance_id)
waiter = self.ec2_client.get_waiter("instance_running")
log.info("Waiting for instance %s to be running.", instance_id)
waiter.wait(InstanceIds=[instance_id])
log.info("Instance %s is now running.", instance_id)
self.ssm_client.send_command(
InstanceIds=[instance_id],
DocumentName="AWS-RunShellScript",
Parameters={"commands": ["cd / && sudo python3 server.py 80"]},
)
log.info(f"Restarted the Python web server on instance '{instance_id}'.")
except ClientError as err:
log.error("Failed to replace instance profile.")
error_code = err.response["Error"]["Code"]
if error_code == "InvalidAssociationID.NotFound":
log.error(
f"Association ID '{profile_association_id}' does not exist."
"Please check the association ID and try again."
)
if error_code == "InvalidInstanceId":
log.error(
f"The specified instance ID '{instance_id}' does not exist or is not available for SSM. "
f"Please verify the instance ID and try again."
)
log.error(f"Full error:\n\t{err}")
def delete_instance_profile(self, profile_name: str, role_name: str) -> None:
"""
Detaches a role from an instance profile, detaches policies from the role,
and deletes all the resources.
:param profile_name: The name of the profile to delete.
:param role_name: The name of the role to delete.
"""
try:
self.iam_client.remove_role_from_instance_profile(
InstanceProfileName=profile_name, RoleName=role_name
)
self.iam_client.delete_instance_profile(InstanceProfileName=profile_name)
log.info("Deleted instance profile %s.", profile_name)
attached_policies = self.iam_client.list_attached_role_policies(
RoleName=role_name
)
for pol in attached_policies["AttachedPolicies"]:
self.iam_client.detach_role_policy(
RoleName=role_name, PolicyArn=pol["PolicyArn"]
)
if not pol["PolicyArn"].startswith("arn:aws:iam::aws"):
self.iam_client.delete_policy(PolicyArn=pol["PolicyArn"])
log.info("Detached and deleted policy %s.", pol["PolicyName"])
self.iam_client.delete_role(RoleName=role_name)
log.info("Deleted role %s.", role_name)
except ClientError as err:
log.error(
f"Couldn't delete instance profile {profile_name} or detach "
f"policies and delete role {role_name}: {err}"
)
if err.response["Error"]["Code"] == "NoSuchEntity":
log.info(
"Instance profile %s doesn't exist, nothing to do.", profile_name
)
def create_key_pair(self, key_pair_name: str) -> None:
"""
Creates a new key pair.
:param key_pair_name: The name of the key pair to create.
"""
try:
response = self.ec2_client.create_key_pair(KeyName=key_pair_name)
with open(f"{key_pair_name}.pem", "w") as file:
file.write(response["KeyMaterial"])
chmod(f"{key_pair_name}.pem", 0o600)
log.info("Created key pair %s.", key_pair_name)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(f"Failed to create key pair {key_pair_name}.")
if error_code == "InvalidKeyPair.Duplicate":
log.error(f"A key pair with the name '{key_pair_name}' already exists.")
log.error(f"Full error:\n\t{err}")
def delete_key_pair(self) -> None:
"""
Deletes a key pair.
"""
try:
self.ec2_client.delete_key_pair(KeyName=self.key_pair_name)
remove(f"{self.key_pair_name}.pem")
log.info("Deleted key pair %s.", self.key_pair_name)
except ClientError as err:
log.error(f"Couldn't delete key pair '{self.key_pair_name}'.")
log.error(f"Full error:\n\t{err}")
except FileNotFoundError as err:
log.info("Key pair %s doesn't exist, nothing to do.", self.key_pair_name)
log.error(f"Full error:\n\t{err}")
def create_template(
self, server_startup_script_file: str, instance_policy_file: str
) -> Dict[str, Any]:
"""
Creates an Amazon EC2 launch template to use with Amazon EC2 Auto Scaling. The
launch template specifies a Bash script in its user data field that runs after
the instance is started. This script installs Python packages and starts a
Python web server on the instance.
:param server_startup_script_file: The path to a Bash script file that is run
when an instance starts.
:param instance_policy_file: The path to a file that defines a permissions policy
to create and attach to the instance profile.
:return: Information about the newly created template.
"""
template = {}
try:
# Create key pair and instance profile
self.create_key_pair(self.key_pair_name)
self.create_instance_profile(
instance_policy_file,
self.instance_policy_name,
self.instance_role_name,
self.instance_profile_name,
)
# Read the startup script
with open(server_startup_script_file) as file:
start_server_script = file.read()
# Get the latest AMI ID
ami_latest = self.ssm_client.get_parameter(Name=self.ami_param)
ami_id = ami_latest["Parameter"]["Value"]
# Create the launch template
lt_response = self.ec2_client.create_launch_template(
LaunchTemplateName=self.launch_template_name,
LaunchTemplateData={
"InstanceType": self.inst_type,
"ImageId": ami_id,
"IamInstanceProfile": {"Name": self.instance_profile_name},
"UserData": base64.b64encode(
start_server_script.encode(encoding="utf-8")
).decode(encoding="utf-8"),
"KeyName": self.key_pair_name,
},
)
template = lt_response["LaunchTemplate"]
log.info(
f"Created launch template {self.launch_template_name} for AMI {ami_id} on {self.inst_type}."
)
except ClientError as err:
log.error(f"Failed to create launch template {self.launch_template_name}.")
error_code = err.response["Error"]["Code"]
if error_code == "InvalidLaunchTemplateName.AlreadyExistsException":
log.info(
f"Launch template {self.launch_template_name} already exists, nothing to do."
)
log.error(f"Full error:\n\t{err}")
return template
def delete_template(self):
"""
Deletes a launch template.
"""
try:
self.ec2_client.delete_launch_template(
LaunchTemplateName=self.launch_template_name
)
self.delete_instance_profile(
self.instance_profile_name, self.instance_role_name
)
log.info("Launch template %s deleted.", self.launch_template_name)
except ClientError as err:
if (
err.response["Error"]["Code"]
== "InvalidLaunchTemplateName.NotFoundException"
):
log.info(
"Launch template %s does not exist, nothing to do.",
self.launch_template_name,
)
log.error(f"Full error:\n\t{err}")
def get_availability_zones(self) -> List[str]:
"""
Gets a list of Availability Zones in the AWS Region of the Amazon EC2 client.
:return: The list of Availability Zones for the client Region.
"""
try:
response = self.ec2_client.describe_availability_zones()
zones = [zone["ZoneName"] for zone in response["AvailabilityZones"]]
log.info(f"Retrieved {len(zones)} availability zones: {zones}.")
except ClientError as err:
log.error("Failed to retrieve availability zones.")
log.error(f"Full error:\n\t{err}")
else:
return zones
def create_autoscaling_group(self, group_size: int) -> List[str]:
"""
Creates an EC2 Auto Scaling group with the specified size.
:param group_size: The number of instances to set for the minimum and maximum in
the group.
:return: The list of Availability Zones specified for the group.
"""
try:
zones = self.get_availability_zones()
self.autoscaling_client.create_auto_scaling_group(
AutoScalingGroupName=self.group_name,
AvailabilityZones=zones,
LaunchTemplate={
"LaunchTemplateName": self.launch_template_name,
"Version": "$Default",
},
MinSize=group_size,
MaxSize=group_size,
)
log.info(
f"Created EC2 Auto Scaling group {self.group_name} with availability zones {zones}."
)
except ClientError as err:
error_code = err.response["Error"]["Code"]
if error_code == "AlreadyExists":
log.info(
f"EC2 Auto Scaling group {self.group_name} already exists, nothing to do."
)
else:
log.error(f"Failed to create EC2 Auto Scaling group {self.group_name}.")
log.error(f"Full error:\n\t{err}")
else:
return zones
def get_instances(self) -> List[str]:
"""
Gets data about the instances in the EC2 Auto Scaling group.
:return: A list of instance IDs in the Auto Scaling group.
"""
try:
as_response = self.autoscaling_client.describe_auto_scaling_groups(
AutoScalingGroupNames=[self.group_name]
)
instance_ids = [
i["InstanceId"]
for i in as_response["AutoScalingGroups"][0]["Instances"]
]
log.info(
f"Retrieved {len(instance_ids)} instances for Auto Scaling group {self.group_name}."
)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to retrieve instances for Auto Scaling group {self.group_name}."
)
if error_code == "ResourceNotFound":
log.error(f"The Auto Scaling group '{self.group_name}' does not exist.")
log.error(f"Full error:\n\t{err}")
else:
return instance_ids
def terminate_instance(self, instance_id: str, decrementsetting=False) -> None:
"""
Terminates an instance in an EC2 Auto Scaling group. After an instance is
terminated, it can no longer be accessed.
:param instance_id: The ID of the instance to terminate.
:param decrementsetting: If True, do not replace terminated instances.
"""
try:
self.autoscaling_client.terminate_instance_in_auto_scaling_group(
InstanceId=instance_id,
ShouldDecrementDesiredCapacity=decrementsetting,
)
log.info("Terminated instance %s.", instance_id)
# Adding a waiter to ensure the instance is terminated
waiter = self.ec2_client.get_waiter("instance_terminated")
log.info("Waiting for instance %s to be terminated...", instance_id)
waiter.wait(InstanceIds=[instance_id])
log.info(
f"Instance '{instance_id}' has been terminated and will be replaced."
)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(f"Failed to terminate instance '{instance_id}'.")
if error_code == "ScalingActivityInProgressFault":
log.error(
"Scaling activity is currently in progress. "
"Wait for the scaling activity to complete before attempting to terminate the instance again."
)
elif error_code == "ResourceContentionFault":
log.error(
"The request failed due to a resource contention issue. "
"Ensure that no conflicting operations are being performed on the resource."
)
log.error(f"Full error:\n\t{err}")
def attach_load_balancer_target_group(
self, lb_target_group: Dict[str, Any]
) -> None:
"""
Attaches an Elastic Load Balancing (ELB) target group to this EC2 Auto Scaling group.
The target group specifies how the load balancer forwards requests to the instances
in the group.
:param lb_target_group: Data about the ELB target group to attach.
"""
try:
self.autoscaling_client.attach_load_balancer_target_groups(
AutoScalingGroupName=self.group_name,
TargetGroupARNs=[lb_target_group["TargetGroupArn"]],
)
log.info(
"Attached load balancer target group %s to auto scaling group %s.",
lb_target_group["TargetGroupName"],
self.group_name,
)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to attach load balancer target group '{lb_target_group['TargetGroupName']}'."
)
if error_code == "ResourceContentionFault":
log.error(
"The request failed due to a resource contention issue. "
"Ensure that no conflicting operations are being performed on the resource."
)
elif error_code == "ServiceLinkedRoleFailure":
log.error(
"The operation failed because the service-linked role is not ready or does not exist. "
"Check that the service-linked role exists and is correctly configured."
)
log.error(f"Full error:\n\t{err}")
def delete_autoscaling_group(self, group_name: str) -> None:
"""
Terminates all instances in the group, then deletes the EC2 Auto Scaling group.
:param group_name: The name of the group to delete.
"""
try:
response = self.autoscaling_client.describe_auto_scaling_groups(
AutoScalingGroupNames=[group_name]
)
groups = response.get("AutoScalingGroups", [])
if len(groups) > 0:
self.autoscaling_client.update_auto_scaling_group(
AutoScalingGroupName=group_name, MinSize=0
)
instance_ids = [inst["InstanceId"] for inst in groups[0]["Instances"]]
for inst_id in instance_ids:
self.terminate_instance(inst_id)
# Wait for all instances to be terminated
if instance_ids:
waiter = self.ec2_client.get_waiter("instance_terminated")
log.info("Waiting for all instances to be terminated...")
waiter.wait(InstanceIds=instance_ids)
log.info("All instances have been terminated.")
else:
log.info(f"No groups found named '{group_name}'! Nothing to do.")
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(f"Failed to delete Auto Scaling group '{group_name}'.")
if error_code == "ScalingActivityInProgressFault":
log.error(
"Scaling activity is currently in progress. "
"Wait for the scaling activity to complete before attempting to delete the group again."
)
elif error_code == "ResourceContentionFault":
log.error(
"The request failed due to a resource contention issue. "
"Ensure that no conflicting operations are being performed on the group."
)
log.error(f"Full error:\n\t{err}")
def get_default_vpc(self) -> Dict[str, Any]:
"""
Gets the default VPC for the account.
:return: Data about the default VPC.
"""
try:
response = self.ec2_client.describe_vpcs(
Filters=[{"Name": "is-default", "Values": ["true"]}]
)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error("Failed to retrieve the default VPC.")
if error_code == "UnauthorizedOperation":
log.error(
"You do not have the necessary permissions to describe VPCs. "
"Ensure that your AWS IAM user or role has the correct permissions."
)
elif error_code == "InvalidParameterValue":
log.error(
"One or more parameters are invalid. Check the request parameters."
)
log.error(f"Full error:\n\t{err}")
else:
if "Vpcs" in response and response["Vpcs"]:
log.info(f"Retrieved default VPC: {response['Vpcs'][0]['VpcId']}")
return response["Vpcs"][0]
else:
pass
def verify_inbound_port(
self, vpc: Dict[str, Any], port: int, ip_address: str
) -> Tuple[Dict[str, Any], bool]:
"""
Verify the default security group of the specified VPC allows ingress from this
computer. This can be done by allowing ingress from this computer's IP
address. In some situations, such as connecting from a corporate network, you
must instead specify a prefix list ID. You can also temporarily open the port to
any IP address while running this example. If you do, be sure to remove public
access when you're done.
:param vpc: The VPC used by this example.
:param port: The port to verify.
:param ip_address: This computer's IP address.
:return: The default security group of the specified VPC, and a value that indicates
whether the specified port is open.
"""
try:
response = self.ec2_client.describe_security_groups(
Filters=[
{"Name": "group-name", "Values": ["default"]},
{"Name": "vpc-id", "Values": [vpc["VpcId"]]},
]
)
sec_group = response["SecurityGroups"][0]
port_is_open = False
log.info(f"Found default security group {sec_group['GroupId']}.")
for ip_perm in sec_group["IpPermissions"]:
if ip_perm.get("FromPort", 0) == port:
log.info(f"Found inbound rule: {ip_perm}")
for ip_range in ip_perm["IpRanges"]:
cidr = ip_range.get("CidrIp", "")
if cidr.startswith(ip_address) or cidr == "0.0.0.0/0":
port_is_open = True
if ip_perm["PrefixListIds"]:
port_is_open = True
if not port_is_open:
log.info(
f"The inbound rule does not appear to be open to either this computer's IP "
f"address of {ip_address}, to all IP addresses (0.0.0.0/0), or to a prefix list ID."
)
else:
break
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to verify inbound rule for port {port} for VPC {vpc['VpcId']}."
)
if error_code == "InvalidVpcID.NotFound":
log.error(
f"The specified VPC ID '{vpc['VpcId']}' does not exist. Please check the VPC ID."
)
log.error(f"Full error:\n\t{err}")
else:
return sec_group, port_is_open
def open_inbound_port(self, sec_group_id: str, port: int, ip_address: str) -> None:
"""
Add an ingress rule to the specified security group that allows access on the
specified port from the specified IP address.
:param sec_group_id: The ID of the security group to modify.
:param port: The port to open.
:param ip_address: The IP address that is granted access.
"""
try:
self.ec2_client.authorize_security_group_ingress(
GroupId=sec_group_id,
CidrIp=f"{ip_address}/32",
FromPort=port,
ToPort=port,
IpProtocol="tcp",
)
log.info(
"Authorized ingress to %s on port %s from %s.",
sec_group_id,
port,
ip_address,
)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to authorize ingress to security group '{sec_group_id}' on port {port} from {ip_address}."
)
if error_code == "InvalidGroupId.Malformed":
log.error(
"The security group ID is malformed. "
"Please verify that the security group ID is correct."
)
elif error_code == "InvalidPermission.Duplicate":
log.error(
"The specified rule already exists in the security group. "
"Check the existing rules for this security group."
)
log.error(f"Full error:\n\t{err}")
def get_subnets(self, vpc_id: str, zones: List[str] = None) -> List[Dict[str, Any]]:
"""
Gets the default subnets in a VPC for a specified list of Availability Zones.
:param vpc_id: The ID of the VPC to look up.
:param zones: The list of Availability Zones to look up.
:return: The list of subnets found.
"""
# Ensure that 'zones' is a list, even if None is passed
if zones is None:
zones = []
try:
paginator = self.ec2_client.get_paginator("describe_subnets")
page_iterator = paginator.paginate(
Filters=[
{"Name": "vpc-id", "Values": [vpc_id]},
{"Name": "availability-zone", "Values": zones},
{"Name": "default-for-az", "Values": ["true"]},
]
)
subnets = []
for page in page_iterator:
subnets.extend(page["Subnets"])
log.info("Found %s subnets for the specified zones.", len(subnets))
return subnets
except ClientError as err:
log.error(
f"Failed to retrieve subnets for VPC '{vpc_id}' in zones {zones}."
)
error_code = err.response["Error"]["Code"]
if error_code == "InvalidVpcID.NotFound":
log.error(
"The specified VPC ID does not exist. "
"Please check the VPC ID and try again."
)
# Add more error-specific handling as needed
log.error(f"Full error:\n\t{err}")
```
Create a class that wraps Elastic Load Balancing actions.
```
class ElasticLoadBalancerWrapper:
"""Encapsulates Elastic Load Balancing (ELB) actions."""
def __init__(self, elb_client: boto3.client):
"""
Initializes the LoadBalancer class with the necessary parameters.
"""
self.elb_client = elb_client
def create_target_group(
self, target_group_name: str, protocol: str, port: int, vpc_id: str
) -> Dict[str, Any]:
"""
Creates an Elastic Load Balancing target group. The target group specifies how
the load balancer forwards requests to instances in the group and how instance
health is checked.
To speed up this demo, the health check is configured with shortened times and
lower thresholds. In production, you might want to decrease the sensitivity of
your health checks to avoid unwanted failures.
:param target_group_name: The name of the target group to create.
:param protocol: The protocol to use to forward requests, such as 'HTTP'.
:param port: The port to use to forward requests, such as 80.
:param vpc_id: The ID of the VPC in which the load balancer exists.
:return: Data about the newly created target group.
"""
try:
response = self.elb_client.create_target_group(
Name=target_group_name,
Protocol=protocol,
Port=port,
HealthCheckPath="/healthcheck",
HealthCheckIntervalSeconds=10,
HealthCheckTimeoutSeconds=5,
HealthyThresholdCount=2,
UnhealthyThresholdCount=2,
VpcId=vpc_id,
)
target_group = response["TargetGroups"][0]
log.info(f"Created load balancing target group '{target_group_name}'.")
return target_group
except ClientError as err:
log.error(
f"Couldn't create load balancing target group '{target_group_name}'."
)
error_code = err.response["Error"]["Code"]
if error_code == "DuplicateTargetGroupName":
log.error(
f"Target group name {target_group_name} already exists. "
"Check if the target group already exists."
"Consider using a different name or deleting the existing target group if appropriate."
)
elif error_code == "TooManyTargetGroups":
log.error(
"Too many target groups exist in the account. "
"Consider deleting unused target groups to create space for new ones."
)
log.error(f"Full error:\n\t{err}")
def delete_target_group(self, target_group_name) -> None:
"""
Deletes the target group.
"""
try:
# Describe the target group to get its ARN
response = self.elb_client.describe_target_groups(Names=[target_group_name])
tg_arn = response["TargetGroups"][0]["TargetGroupArn"]
# Delete the target group
self.elb_client.delete_target_group(TargetGroupArn=tg_arn)
log.info("Deleted load balancing target group %s.", target_group_name)
# Use a custom waiter to wait until the target group is no longer available
self.wait_for_target_group_deletion(self.elb_client, tg_arn)
log.info("Target group %s successfully deleted.", target_group_name)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(f"Failed to delete target group '{target_group_name}'.")
if error_code == "TargetGroupNotFound":
log.error(
"Load balancer target group either already deleted or never existed. "
"Verify the name and check that the resource exists in the AWS Console."
)
elif error_code == "ResourceInUseException":
log.error(
"Target group still in use by another resource. "
"Ensure that the target group is no longer associated with any load balancers or resources.",
)
log.error(f"Full error:\n\t{err}")
def wait_for_target_group_deletion(
self, elb_client, target_group_arn, max_attempts=10, delay=30
):
for attempt in range(max_attempts):
try:
elb_client.describe_target_groups(TargetGroupArns=[target_group_arn])
print(
f"Attempt {attempt + 1}: Target group {target_group_arn} still exists."
)
except ClientError as e:
if e.response["Error"]["Code"] == "TargetGroupNotFound":
print(
f"Target group {target_group_arn} has been successfully deleted."
)
return
else:
raise
time.sleep(delay)
raise TimeoutError(
f"Target group {target_group_arn} was not deleted after {max_attempts * delay} seconds."
)
def create_load_balancer(
self,
load_balancer_name: str,
subnet_ids: List[str],
) -> Dict[str, Any]:
"""
Creates an Elastic Load Balancing load balancer that uses the specified subnets
and forwards requests to the specified target group.
:param load_balancer_name: The name of the load balancer to create.
:param subnet_ids: A list of subnets to associate with the load balancer.
:return: Data about the newly created load balancer.
"""
try:
response = self.elb_client.create_load_balancer(
Name=load_balancer_name, Subnets=subnet_ids
)
load_balancer = response["LoadBalancers"][0]
log.info(f"Created load balancer '{load_balancer_name}'.")
waiter = self.elb_client.get_waiter("load_balancer_available")
log.info(
f"Waiting for load balancer '{load_balancer_name}' to be available..."
)
waiter.wait(Names=[load_balancer_name])
log.info(f"Load balancer '{load_balancer_name}' is now available!")
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to create load balancer '{load_balancer_name}'. Error code: {error_code}, Message: {err.response['Error']['Message']}"
)
if error_code == "DuplicateLoadBalancerNameException":
log.error(
f"A load balancer with the name '{load_balancer_name}' already exists. "
"Load balancer names must be unique within the AWS region. "
"Please choose a different name and try again."
)
if error_code == "TooManyLoadBalancersException":
log.error(
"The maximum number of load balancers has been reached in this account and region. "
"You can delete unused load balancers or request an increase in the service quota from AWS Support."
)
log.error(f"Full error:\n\t{err}")
else:
return load_balancer
def create_listener(
self,
load_balancer_name: str,
target_group: Dict[str, Any],
) -> Dict[str, Any]:
"""
Creates a listener for the specified load balancer that forwards requests to the
specified target group.
:param load_balancer_name: The name of the load balancer to create a listener for.
:param target_group: An existing target group that is added as a listener to the
load balancer.
:return: Data about the newly created listener.
"""
try:
# Retrieve the load balancer ARN
load_balancer_response = self.elb_client.describe_load_balancers(
Names=[load_balancer_name]
)
load_balancer_arn = load_balancer_response["LoadBalancers"][0][
"LoadBalancerArn"
]
# Create the listener
response = self.elb_client.create_listener(
LoadBalancerArn=load_balancer_arn,
Protocol=target_group["Protocol"],
Port=target_group["Port"],
DefaultActions=[
{
"Type": "forward",
"TargetGroupArn": target_group["TargetGroupArn"],
}
],
)
log.info(
f"Created listener to forward traffic from load balancer '{load_balancer_name}' to target group '{target_group['TargetGroupName']}'."
)
return response["Listeners"][0]
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Failed to add a listener on '{load_balancer_name}' for target group '{target_group['TargetGroupName']}'."
)
if error_code == "ListenerNotFoundException":
log.error(
f"The listener could not be found for the load balancer '{load_balancer_name}'. "
"Please check the load balancer name and target group configuration."
)
if error_code == "InvalidConfigurationRequestException":
log.error(
f"The configuration provided for the listener on load balancer '{load_balancer_name}' is invalid. "
"Please review the provided protocol, port, and target group settings."
)
log.error(f"Full error:\n\t{err}")
def delete_load_balancer(self, load_balancer_name) -> None:
"""
Deletes a load balancer.
:param load_balancer_name: The name of the load balancer to delete.
"""
try:
response = self.elb_client.describe_load_balancers(
Names=[load_balancer_name]
)
lb_arn = response["LoadBalancers"][0]["LoadBalancerArn"]
self.elb_client.delete_load_balancer(LoadBalancerArn=lb_arn)
log.info("Deleted load balancer %s.", load_balancer_name)
waiter = self.elb_client.get_waiter("load_balancers_deleted")
log.info("Waiting for load balancer to be deleted...")
waiter.wait(Names=[load_balancer_name])
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(
f"Couldn't delete load balancer '{load_balancer_name}'. Error code: {error_code}, Message: {err.response['Error']['Message']}"
)
if error_code == "LoadBalancerNotFoundException":
log.error(
f"The load balancer '{load_balancer_name}' does not exist. "
"Please check the name and try again."
)
log.error(f"Full error:\n\t{err}")
def get_endpoint(self, load_balancer_name) -> str:
"""
Gets the HTTP endpoint of the load balancer.
:return: The endpoint.
"""
try:
response = self.elb_client.describe_load_balancers(
Names=[load_balancer_name]
)
return response["LoadBalancers"][0]["DNSName"]
except ClientError as err:
log.error(
f"Couldn't get the endpoint for load balancer {load_balancer_name}"
)
error_code = err.response["Error"]["Code"]
if error_code == "LoadBalancerNotFoundException":
log.error(
"Verify load balancer name and ensure it exists in the AWS console."
)
log.error(f"Full error:\n\t{err}")
@staticmethod
def verify_load_balancer_endpoint(endpoint) -> bool:
"""
Verify this computer can successfully send a GET request to the load balancer endpoint.
:param endpoint: The endpoint to verify.
:return: True if the GET request is successful, False otherwise.
"""
retries = 3
verified = False
while not verified and retries > 0:
try:
lb_response = requests.get(f"http://{endpoint}")
log.info(
"Got response %s from load balancer endpoint.",
lb_response.status_code,
)
if lb_response.status_code == 200:
verified = True
else:
retries = 0
except requests.exceptions.ConnectionError:
log.info(
"Got connection error from load balancer endpoint, retrying..."
)
retries -= 1
time.sleep(10)
return verified
def check_target_health(self, target_group_name: str) -> List[Dict[str, Any]]:
"""
Checks the health of the instances in the target group.
:return: The health status of the target group.
"""
try:
tg_response = self.elb_client.describe_target_groups(
Names=[target_group_name]
)
health_response = self.elb_client.describe_target_health(
TargetGroupArn=tg_response["TargetGroups"][0]["TargetGroupArn"]
)
except ClientError as err:
log.error(f"Couldn't check health of {target_group_name} target(s).")
error_code = err.response["Error"]["Code"]
if error_code == "LoadBalancerNotFoundException":
log.error(
"Load balancer associated with the target group was not found. "
"Ensure the load balancer exists, is in the correct AWS region, and "
"that you have the necessary permissions to access it.",
)
elif error_code == "TargetGroupNotFoundException":
log.error(
"Target group was not found. "
"Verify the target group name, check that it exists in the correct region, "
"and ensure it has not been deleted or created in a different account.",
)
log.error(f"Full error:\n\t{err}")
else:
return health_response["TargetHealthDescriptions"]
```
Create a class that uses DynamoDB to simulate a recommendation service.
```
class RecommendationService:
"""
Encapsulates a DynamoDB table to use as a service that recommends books, movies,
and songs.
"""
def __init__(self, table_name: str, dynamodb_client: boto3.client):
"""
Initializes the RecommendationService class with the necessary parameters.
:param table_name: The name of the DynamoDB recommendations table.
:param dynamodb_client: A Boto3 DynamoDB client.
"""
self.table_name = table_name
self.dynamodb_client = dynamodb_client
def create(self) -> Dict[str, Any]:
"""
Creates a DynamoDB table to use as a recommendation service. The table has a
hash key named 'MediaType' that defines the type of media recommended, such as
Book or Movie, and a range key named 'ItemId' that, combined with the MediaType,
forms a unique identifier for the recommended item.
:return: Data about the newly created table.
:raises RecommendationServiceError: If the table creation fails.
"""
try:
response = self.dynamodb_client.create_table(
TableName=self.table_name,
AttributeDefinitions=[
{"AttributeName": "MediaType", "AttributeType": "S"},
{"AttributeName": "ItemId", "AttributeType": "N"},
],
KeySchema=[
{"AttributeName": "MediaType", "KeyType": "HASH"},
{"AttributeName": "ItemId", "KeyType": "RANGE"},
],
ProvisionedThroughput={"ReadCapacityUnits": 5, "WriteCapacityUnits": 5},
)
log.info("Creating table %s...", self.table_name)
waiter = self.dynamodb_client.get_waiter("table_exists")
waiter.wait(TableName=self.table_name)
log.info("Table %s created.", self.table_name)
except ClientError as err:
if err.response["Error"]["Code"] == "ResourceInUseException":
log.info("Table %s exists, nothing to be done.", self.table_name)
else:
raise RecommendationServiceError(
self.table_name, f"ClientError when creating table: {err}."
)
else:
return response
def populate(self, data_file: str) -> None:
"""
Populates the recommendations table from a JSON file.
:param data_file: The path to the data file.
:raises RecommendationServiceError: If the table population fails.
"""
try:
with open(data_file) as data:
items = json.load(data)
batch = [{"PutRequest": {"Item": item}} for item in items]
self.dynamodb_client.batch_write_item(RequestItems={self.table_name: batch})
log.info(
"Populated table %s with items from %s.", self.table_name, data_file
)
except ClientError as err:
raise RecommendationServiceError(
self.table_name, f"Couldn't populate table from {data_file}: {err}"
)
def destroy(self) -> None:
"""
Deletes the recommendations table.
:raises RecommendationServiceError: If the table deletion fails.
"""
try:
self.dynamodb_client.delete_table(TableName=self.table_name)
log.info("Deleting table %s...", self.table_name)
waiter = self.dynamodb_client.get_waiter("table_not_exists")
waiter.wait(TableName=self.table_name)
log.info("Table %s deleted.", self.table_name)
except ClientError as err:
if err.response["Error"]["Code"] == "ResourceNotFoundException":
log.info("Table %s does not exist, nothing to do.", self.table_name)
else:
raise RecommendationServiceError(
self.table_name, f"ClientError when deleting table: {err}."
)
```
Create a class that wraps Systems Manager actions.
```
class ParameterHelper:
"""
Encapsulates Systems Manager parameters. This example uses these parameters to drive
the demonstration of resilient architecture, such as failure of a dependency or
how the service responds to a health check.
"""
table: str = "doc-example-resilient-architecture-table"
failure_response: str = "doc-example-resilient-architecture-failure-response"
health_check: str = "doc-example-resilient-architecture-health-check"
def __init__(self, table_name: str, ssm_client: boto3.client):
"""
Initializes the ParameterHelper class with the necessary parameters.
:param table_name: The name of the DynamoDB table that is used as a recommendation
service.
:param ssm_client: A Boto3 Systems Manager client.
"""
self.ssm_client = ssm_client
self.table_name = table_name
def reset(self) -> None:
"""
Resets the Systems Manager parameters to starting values for the demo.
These are the name of the DynamoDB recommendation table, no response when a
dependency fails, and shallow health checks.
"""
self.put(self.table, self.table_name)
self.put(self.failure_response, "none")
self.put(self.health_check, "shallow")
def put(self, name: str, value: str) -> None:
"""
Sets the value of a named Systems Manager parameter.
:param name: The name of the parameter.
:param value: The new value of the parameter.
:raises ParameterHelperError: If the parameter value cannot be set.
"""
try:
self.ssm_client.put_parameter(
Name=name, Value=value, Overwrite=True, Type="String"
)
log.info("Setting parameter %s to '%s'.", name, value)
except ClientError as err:
error_code = err.response["Error"]["Code"]
log.error(f"Failed to set parameter {name}.")
if error_code == "ParameterLimitExceeded":
log.error(
"The parameter limit has been exceeded. "
"Consider deleting unused parameters or request a limit increase."
)
elif error_code == "ParameterAlreadyExists":
log.error(
"The parameter already exists and overwrite is set to False. "
"Use Overwrite=True to update the parameter."
)
log.error(f"Full error:\n\t{err}")
```
+ For API details, see the following topics in *AWS SDK for Python (Boto3) API Reference*.
+ [AttachLoadBalancerTargetGroups](https://docs.aws.amazon.com/goto/boto3/autoscaling-2011-01-01/AttachLoadBalancerTargetGroups)
+ [CreateAutoScalingGroup](https://docs.aws.amazon.com/goto/boto3/autoscaling-2011-01-01/CreateAutoScalingGroup)
+ [CreateInstanceProfile](https://docs.aws.amazon.com/goto/boto3/iam-2010-05-08/CreateInstanceProfile)
+ [CreateLaunchTemplate](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/CreateLaunchTemplate)
+ [CreateListener](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/CreateListener)
+ [CreateLoadBalancer](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/CreateLoadBalancer)
+ [CreateTargetGroup](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/CreateTargetGroup)
+ [DeleteAutoScalingGroup](https://docs.aws.amazon.com/goto/boto3/autoscaling-2011-01-01/DeleteAutoScalingGroup)
+ [DeleteInstanceProfile](https://docs.aws.amazon.com/goto/boto3/iam-2010-05-08/DeleteInstanceProfile)
+ [DeleteLaunchTemplate](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/DeleteLaunchTemplate)
+ [DeleteLoadBalancer](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DeleteLoadBalancer)
+ [DeleteTargetGroup](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DeleteTargetGroup)
+ [DescribeAutoScalingGroups](https://docs.aws.amazon.com/goto/boto3/autoscaling-2011-01-01/DescribeAutoScalingGroups)
+ [DescribeAvailabilityZones](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/DescribeAvailabilityZones)
+ [DescribeIamInstanceProfileAssociations](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/DescribeIamInstanceProfileAssociations)
+ [DescribeInstances](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/DescribeInstances)
+ [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers)
+ [DescribeSubnets](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/DescribeSubnets)
+ [DescribeTargetGroups](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DescribeTargetGroups)
+ [DescribeTargetHealth](https://docs.aws.amazon.com/goto/boto3/elasticloadbalancingv2-2015-12-01/DescribeTargetHealth)
+ [DescribeVpcs](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/DescribeVpcs)
+ [RebootInstances](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/RebootInstances)
+ [ReplaceIamInstanceProfileAssociation](https://docs.aws.amazon.com/goto/boto3/ec2-2016-11-15/ReplaceIamInstanceProfileAssociation)
+ [TerminateInstanceInAutoScalingGroup](https://docs.aws.amazon.com/goto/boto3/autoscaling-2011-01-01/TerminateInstanceInAutoScalingGroup)
+ [UpdateAutoScalingGroup](https://docs.aws.amazon.com/goto/boto3/autoscaling-2011-01-01/UpdateAutoScalingGroup)
------
# Getting started with Elastic Load Balancing
The following code example shows how to:
+ Create an Application Load Balancer
+ Create a target group
+ Create a listener
+ Verify your configuration
+ Add an HTTPS listener (optional)
+ Add path-based routing (optional)
+ Clean up resources
------
#### [ Bash ]
**AWS CLI with Bash script**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Sample developer tutorials](https://github.com/aws-samples/sample-developer-tutorials/tree/main/tuts/058-elastic-load-balancing-gs) repository.
```
#!/bin/bash
# Elastic Load Balancing Getting Started Script - v2
# This script creates an Application Load Balancer with HTTP listener and target group
# Set up logging
LOG_FILE="elb-script-v2.log"
exec > >(tee -a "$LOG_FILE") 2>&1
echo "Starting Elastic Load Balancing setup script at $(date)"
echo "All commands and outputs will be logged to $LOG_FILE"
# Function to handle errors
handle_error() {
echo "ERROR: $1"
echo "Attempting to clean up resources..."
cleanup_resources
exit 1
}
# Function to check command success
check_command() {
if echo "$1" | grep -i "error" > /dev/null; then
handle_error "$1"
fi
}
# Function to clean up resources
cleanup_resources() {
echo "Cleaning up resources in reverse order..."
if [ -n "$LISTENER_ARN" ]; then
echo "Deleting listener: $LISTENER_ARN"
aws elbv2 delete-listener --listener-arn "$LISTENER_ARN"
fi
if [ -n "$LOAD_BALANCER_ARN" ]; then
echo "Deleting load balancer: $LOAD_BALANCER_ARN"
aws elbv2 delete-load-balancer --load-balancer-arn "$LOAD_BALANCER_ARN"
# Wait for load balancer to be deleted before deleting target group
echo "Waiting for load balancer to be deleted..."
aws elbv2 wait load-balancers-deleted --load-balancer-arns "$LOAD_BALANCER_ARN"
fi
if [ -n "$TARGET_GROUP_ARN" ]; then
echo "Deleting target group: $TARGET_GROUP_ARN"
aws elbv2 delete-target-group --target-group-arn "$TARGET_GROUP_ARN"
fi
# Add a delay before attempting to delete the security group
# to ensure all ELB resources are fully deleted
if [ -n "$SECURITY_GROUP_ID" ]; then
echo "Waiting 30 seconds before deleting security group to ensure all dependencies are removed..."
sleep 30
echo "Deleting security group: $SECURITY_GROUP_ID"
SG_DELETE_OUTPUT=$(aws ec2 delete-security-group --group-id "$SECURITY_GROUP_ID" 2>&1)
# If there's still a dependency issue, retry a few times
RETRY_COUNT=0
MAX_RETRIES=5
while echo "$SG_DELETE_OUTPUT" | grep -i "DependencyViolation" > /dev/null && [ $RETRY_COUNT -lt $MAX_RETRIES ]; do
RETRY_COUNT=$((RETRY_COUNT+1))
echo "Security group still has dependencies. Retrying in 30 seconds... (Attempt $RETRY_COUNT of $MAX_RETRIES)"
sleep 30
SG_DELETE_OUTPUT=$(aws ec2 delete-security-group --group-id "$SECURITY_GROUP_ID" 2>&1)
done
if echo "$SG_DELETE_OUTPUT" | grep -i "error" > /dev/null; then
echo "WARNING: Could not delete security group: $SECURITY_GROUP_ID"
echo "You may need to delete it manually using: aws ec2 delete-security-group --group-id $SECURITY_GROUP_ID"
else
echo "Security group deleted successfully."
fi
fi
}
# Generate a random identifier for resource names
RANDOM_ID=$(openssl rand -hex 4)
RESOURCE_PREFIX="elb-demo-${RANDOM_ID}"
# Step 1: Verify AWS CLI support for Elastic Load Balancing
echo "Verifying AWS CLI support for Elastic Load Balancing..."
aws elbv2 help > /dev/null 2>&1
if [ $? -ne 0 ]; then
handle_error "AWS CLI does not support elbv2 commands. Please update your AWS CLI."
fi
# Step 2: Get VPC ID and subnet information
echo "Retrieving VPC information..."
VPC_INFO=$(aws ec2 describe-vpcs --filters "Name=isDefault,Values=true" --query "Vpcs[0].VpcId" --output text)
check_command "$VPC_INFO"
VPC_ID=$VPC_INFO
echo "Using VPC: $VPC_ID"
# Get two subnets from different Availability Zones
echo "Retrieving subnet information..."
SUBNET_INFO=$(aws ec2 describe-subnets --filters "Name=vpc-id,Values=$VPC_ID" --query "Subnets[0:2].SubnetId" --output text)
check_command "$SUBNET_INFO"
# Convert space-separated list to array
read -r -a SUBNETS <<< "$SUBNET_INFO"
if [ ${#SUBNETS[@]} -lt 2 ]; then
handle_error "Need at least 2 subnets in different Availability Zones. Found: ${#SUBNETS[@]}"
fi
echo "Using subnets: ${SUBNETS[0]} and ${SUBNETS[1]}"
# Step 3: Create a security group for the load balancer
echo "Creating security group for the load balancer..."
SG_INFO=$(aws ec2 create-security-group \
--group-name "${RESOURCE_PREFIX}-sg" \
--description "Security group for ELB demo" \
--vpc-id "$VPC_ID" \
--query "GroupId" --output text)
check_command "$SG_INFO"
SECURITY_GROUP_ID=$SG_INFO
echo "Created security group: $SECURITY_GROUP_ID"
# Add inbound rule to allow HTTP traffic
echo "Adding inbound rule to allow HTTP traffic..."
aws ec2 authorize-security-group-ingress \
--group-id "$SECURITY_GROUP_ID" \
--protocol tcp \
--port 80 \
--cidr "0.0.0.0/0" > /dev/null
# Note: In production, you should restrict the CIDR range to specific IP addresses
# Step 4: Create the load balancer
echo "Creating Application Load Balancer..."
LB_INFO=$(aws elbv2 create-load-balancer \
--name "${RESOURCE_PREFIX}-lb" \
--subnets "${SUBNETS[0]}" "${SUBNETS[1]}" \
--security-groups "$SECURITY_GROUP_ID" \
--query "LoadBalancers[0].LoadBalancerArn" --output text)
check_command "$LB_INFO"
LOAD_BALANCER_ARN=$LB_INFO
echo "Created load balancer: $LOAD_BALANCER_ARN"
# Wait for the load balancer to be active
echo "Waiting for load balancer to become active..."
aws elbv2 wait load-balancer-available --load-balancer-arns "$LOAD_BALANCER_ARN"
# Step 5: Create a target group
echo "Creating target group..."
TG_INFO=$(aws elbv2 create-target-group \
--name "${RESOURCE_PREFIX}-targets" \
--protocol HTTP \
--port 80 \
--vpc-id "$VPC_ID" \
--target-type instance \
--query "TargetGroups[0].TargetGroupArn" --output text)
check_command "$TG_INFO"
TARGET_GROUP_ARN=$TG_INFO
echo "Created target group: $TARGET_GROUP_ARN"
# Step 6: Find EC2 instances to register as targets
echo "Looking for available EC2 instances to register as targets..."
INSTANCES=$(aws ec2 describe-instances \
--filters "Name=vpc-id,Values=$VPC_ID" "Name=instance-state-name,Values=running" \
--query "Reservations[*].Instances[*].InstanceId" --output text)
check_command "$INSTANCES"
# Convert space-separated list to array
read -r -a INSTANCE_IDS <<< "$INSTANCES"
if [ ${#INSTANCE_IDS[@]} -eq 0 ]; then
echo "No running instances found in VPC $VPC_ID."
echo "You will need to register targets manually after launching instances."
else
# Step 7: Register targets with the target group (up to 2 instances)
echo "Registering targets with the target group..."
TARGET_ARGS=""
for i in "${!INSTANCE_IDS[@]}"; do
if [ "$i" -lt 2 ]; then # Register up to 2 instances
TARGET_ARGS="$TARGET_ARGS Id=${INSTANCE_IDS[$i]} "
fi
done
if [ -n "$TARGET_ARGS" ]; then
aws elbv2 register-targets \
--target-group-arn "$TARGET_GROUP_ARN" \
--targets $TARGET_ARGS
echo "Registered instances: $TARGET_ARGS"
fi
fi
# Step 8: Create a listener
echo "Creating HTTP listener..."
LISTENER_INFO=$(aws elbv2 create-listener \
--load-balancer-arn "$LOAD_BALANCER_ARN" \
--protocol HTTP \
--port 80 \
--default-actions Type=forward,TargetGroupArn="$TARGET_GROUP_ARN" \
--query "Listeners[0].ListenerArn" --output text)
check_command "$LISTENER_INFO"
LISTENER_ARN=$LISTENER_INFO
echo "Created listener: $LISTENER_ARN"
# Step 9: Verify target health
echo "Verifying target health..."
aws elbv2 describe-target-health --target-group-arn "$TARGET_GROUP_ARN"
# Display load balancer DNS name
LB_DNS=$(aws elbv2 describe-load-balancers \
--load-balancer-arns "$LOAD_BALANCER_ARN" \
--query "LoadBalancers[0].DNSName" --output text)
check_command "$LB_DNS"
echo ""
echo "=============================================="
echo "SETUP COMPLETE"
echo "=============================================="
echo "Load Balancer DNS Name: $LB_DNS"
echo ""
echo "Resources created:"
echo "- Load Balancer: $LOAD_BALANCER_ARN"
echo "- Target Group: $TARGET_GROUP_ARN"
echo "- Listener: $LISTENER_ARN"
echo "- Security Group: $SECURITY_GROUP_ID"
echo ""
# Ask user if they want to clean up resources
echo "=============================================="
echo "CLEANUP CONFIRMATION"
echo "=============================================="
echo "Do you want to clean up all created resources? (y/n): "
read -r CLEANUP_CHOICE
if [[ "$CLEANUP_CHOICE" =~ ^[Yy] ]]; then
echo "Starting cleanup process..."
cleanup_resources
echo "Cleanup completed."
else
echo "Resources have been preserved."
echo "To clean up later, run the following commands:"
echo "aws elbv2 delete-listener --listener-arn $LISTENER_ARN"
echo "aws elbv2 delete-load-balancer --load-balancer-arn $LOAD_BALANCER_ARN"
echo "aws elbv2 wait load-balancers-deleted --load-balancer-arns $LOAD_BALANCER_ARN"
echo "aws elbv2 delete-target-group --target-group-arn $TARGET_GROUP_ARN"
echo "aws ec2 delete-security-group --group-id $SECURITY_GROUP_ID"
fi
echo "Script completed at $(date)"
```
+ For API details, see the following topics in *AWS CLI Command Reference*.
+ [AuthorizeSecurityGroupIngress](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/AuthorizeSecurityGroupIngress)
+ [CreateListener](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/CreateListener)
+ [CreateLoadBalancer](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/CreateLoadBalancer)
+ [CreateSecurityGroup](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/CreateSecurityGroup)
+ [CreateTargetGroup](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/CreateTargetGroup)
+ [DeleteListener](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/DeleteListener)
+ [DeleteLoadBalancer](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/DeleteLoadBalancer)
+ [DeleteSecurityGroup](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/DeleteSecurityGroup)
+ [DeleteTargetGroup](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/DeleteTargetGroup)
+ [DescribeInstances](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/DescribeInstances)
+ [DescribeLoadBalancers](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/DescribeLoadBalancers)
+ [DescribeSubnets](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/DescribeSubnets)
+ [DescribeTargetHealth](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/DescribeTargetHealth)
+ [DescribeVpcs](https://docs.aws.amazon.com/goto/aws-cli/ec2-2016-11-15/DescribeVpcs)
+ [Help](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/Help)
+ [RegisterTargets](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/RegisterTargets)
+ [Wait](https://docs.aws.amazon.com/goto/aws-cli/elasticloadbalancingv2-2015-12-01/Wait)
------