Creating your first stack - AWS CloudFormation
PrerequisitesCreate a CloudFormation stack with the consoleMonitor stack creationTest the web serverClean upNext steps

Creating your first stack

This topic walks you through creating your first CloudFormation stack using the AWS Management Console. By following this tutorial, you'll learn how to provision basic AWS resources, monitor stack events, and generate outputs.

For this example, the CloudFormation template is written in YAML. YAML is a human-readable format that's widely used for defining infrastructure as code. As you learn more about CloudFormation, you might also encounter other templates in JSON format, but for this tutorial, YAML is chosen for its readability.

If you're interested in a guided and hands-on course to try CloudFormation, see the Getting Started with AWS CloudFormation workshop.

Note

CloudFormation is free, but you'll be charged for the Amazon EC2 and Amazon S3 resources you create. However, if you're new to AWS, you can take advantage of the Free Tier to minimize or eliminate costs during this learning process.

Prerequisites

  • You must have access to an AWS account with an IAM user or role that has permissions to use Amazon EC2, Amazon S3, and CloudFormation, or administrative user access.

  • You must have a Virtual Private Cloud (VPC) that has access to the internet. To keep things simple, you can use the default VPC that comes automatically with your account. The default VPC and default subnets are sufficient for this exercise.

Create a CloudFormation stack with the console

To create a Hello world CloudFormation stack with the console

  1. Open the CloudFormation console.

  2. Choose Create Stack.

  3. On the Create stack page, choose Build from Infrastructure Composer, and then Create in Infrastructure Composer. This takes you to Infrastructure Composer in CloudFormation console mode where you can upload and validate the example template.

  4. To upload and validate the example template, do the following:

    1. Choose Template. Then, copy and paste the following CloudFormation template into the template editor:

      AWSTemplateFormatVersion: 2010-09-09
Description: CloudFormation Template for WebServer with Security Group and EC2 Instance

Parameters:
  LatestAmiId:
    Description: The latest Amazon Linux 2 AMI from the Parameter Store
    Type: 'AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>'
    Default: '/aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2'

  InstanceType:
    Description: WebServer EC2 instance type
    Type: String
    Default: t2.micro
    AllowedValues:
      - t3.micro
      - t2.micro
    ConstraintDescription: must be a valid EC2 instance type.
    
  MyIP:
    Description: Your IP address in CIDR format (e.g. 203.0.113.1/32).
    Type: String
    MinLength: '9'
    MaxLength: '18'
    Default: 0.0.0.0/0
    AllowedPattern: '^(\d{1,3}\.){3}\d{1,3}\/\d{1,2}$'
    ConstraintDescription: must be a valid IP CIDR range of the form x.x.x.x/x.

Resources:
  WebServerSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow HTTP access via my IP address
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: '80'
          ToPort: '80'
          CidrIp: !Ref MyIP

  WebServer:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref LatestAmiId
      InstanceType: !Ref InstanceType
      SecurityGroupIds:
        - !Ref WebServerSecurityGroup
      UserData: !Base64 |
        #!/bin/bash
        yum update -y
        yum install -y httpd
        systemctl start httpd
        systemctl enable httpd
        echo "<html><body><h1>Hello World!</h1></body></html>" > /var/www/html/index.html

Outputs:
  WebsiteURL:
    Value: !Join
      - ''
      - - http://
        - !GetAtt WebServer.PublicDnsName
    Description: Website URL

      Before you move to the next step, let's take a moment to take a look at the template and understand some key CloudFormation concepts.

      • The Parameters section declares values that can be passed to the template when you create the stack. Resources specified later in the template reference these values and use the data. Parameters are an effective way to specify information that you don't want to store in the template itself. They're also a way to specify information that might be unique to the specific application or configuration you are deploying.

      • The template defines the following parameters:

        • LatestAmiId – Retrieves the latest Amazon Linux 2 AMI ID from the AWS Systems Manager Parameter Store.

        • InstanceType – Allows selection of the EC2 instance type (default: t2.micro, allowed: t3.micro, t2.micro).

        • MyIP – Specifies the IP address range for HTTP access (default: 0.0.0.0/0, allowing access from any IP).

      • The Resources section contains the definitions of the AWS resources you want to create with the template. Resource declarations are an efficient way to specify all these configuration settings at once. When you include resource declarations in a template, you can create and configure all the declared resources by using that template to create a stack. You can also create new stacks from the same template to launch identical configurations of resources.

      • This template creates the following resources:

        • WebServerSecurityGroup – An EC2 security group that allows inbound HTTP traffic on port 80 from the specified IP range.

        • WebServer – An EC2 instance with the following configuration:

          • Uses the latest Amazon Linux 2 AMI

          • Applies the selected instance type

          • Adds the WebServerSecurityGroup to the SecurityGroupIds property

          • Includes a user data script to install Apache HTTP Server

      • A logical name is specified at the beginning of each resource and parameter declaration. For example, WebServerSecurityGroup is the logical name assigned to the EC2 security group resource. The Ref function is then used to reference resources and parameters by their logical names in other parts of the template. When one resource references another resource, this creates a dependency between them.

      • The Outputs section defines custom values that are returned after the stack creation. You can use the output values to return information from the resources in the stack, such as resource identifiers or URLs.

      • The template defines one output:

        • WebsiteURL – The URL of the deployed web server, constructed using the EC2 instance's public DNS name. The Join function helps combine the fixed http:// with the variable PublicDnsName into a single string, making it easy to output the full URL of the web server.

    2. Choose Validate to make sure the YAML code is valid before uploading the template.

    3. Next, choose Create template to create the template and add it to an S3 bucket.

    4. From the dialog box that opens, make a note of the name of the S3 bucket so you can delete it later. Then, choose Confirm and continue to CloudFormation. This takes you to the CloudFormation console where the S3 path to your template is now specified.

  5. On the Create stack page, choose Next.

  6. On the Specify stack details page, type a name in the Stack name field. The stack name can't contain spaces. For this example, use MyTestStack.

  7. Under Parameters, specify parameter values as follows:

    • LatestAmiId: This is set by default to the latest Amazon Linux 2 AMI.

    • InstanceType: Choose either t2.micro or t3.micro for the EC2 instance type.

      Note

      If you're new to AWS, you can use the free tier to launch and use a t2.micro instance for free for 12 months (in Regions where t2.micro is unavailable, you can use a t3.micro instance under the free tier).

    • MyIP: Specify your actual public IP address with a /32 suffix. The /32 suffix is used in CIDR notation to specify that a single IP address is allowed. It essentially means allow traffic to and from this specific IP address, and no others.

  8. Choose Next twice to go to the Review and create page. For this tutorial, you can leave the defaults on the Configure stack options page as they are.

  9. Review the information for the stack. When you're satisfied with the settings, choose Submit.

Monitor stack creation

After you choose Submit, CloudFormation begins creating the resources that are specified in the template. Your new stack, MyTestStack, appears in the list at the top portion of the CloudFormation console. Its status should be CREATE_IN_PROGRESS. You can see detailed status for a stack by viewing its events.

To view the events for the stack

  1. On the CloudFormation console, choose the stack MyTestStack in the list.

  2. In the stack details pane, choose the Events tab.

    The console automatically refreshes the event list with the most recent events every 60 seconds.

The Events tab displays each major step in the creation of the stack sorted by the time of each event, with latest events on top.

The first event (at the bottom of the event list) is the start of the stack creation process:

2024-12-23 18:54 UTC-7 MyTestStack CREATE_IN_PROGRESS User initiated

Next are events that mark the beginning and completion of the creation of each resource. For example, creation of the EC2 instance results in the following entries:

2024-12-23 18:59 UTC-7 WebServer CREATE_COMPLETE

2024-12-23 18:54 UTC-7 WebServer CREATE_IN_PROGRESS Resource creation initiated

The CREATE_IN_PROGRESS event is logged when CloudFormation reports that it has begun to create the resource. The CREATE_COMPLETE event is logged when the resource is successfully created.

When CloudFormation has successfully created the stack, you will see the following event at the top of the Events tab:

2024-12-23 19:17 UTC-7 MyTestStack CREATE_COMPLETE

If CloudFormation can't create a resource, it reports a CREATE_FAILED event and, by default, rolls back the stack and deletes any resources that have been created. The Status Reason column displays the issue that caused the failure.

After the stack is created, you can go to the Resources tab to view the EC2 instance and security group you created.

Test the web server

After the stack is successfully created, navigate to the Outputs tab in the CloudFormation console. Look for the WebsiteURL field. This will contain the public URL of your EC2 instance.

Open a browser and go to the URL listed under WebsiteURL. You should see a simple "Hello World!" message displayed in the browser.

This confirms that your EC2 instance is running Apache HTTP Server and serving a basic web page.

Clean up

To make sure you aren't charged for any unwanted services, you can clean up by deleting the stack and its resources. You can also delete the S3 bucket that stores the stack's template.

To delete the stack and its resources

  1. Open the CloudFormation console.

  2. On the Stacks page, select the option next to the name of the stack you created (MyTestStack) and then choose Delete.

  3. When prompted for confirmation, choose Delete.

  4. Monitor the progress of the stack deletion process on the Event tab. The status for MyTestStack changes to DELETE_IN_PROGRESS. When CloudFormation completes the deletion of the stack, it removes the stack from the list.

If you are done working with the example template and no longer need your Amazon S3 bucket, delete it. Before you can delete a bucket, you must first empty it. Emptying a bucket deletes all objects in it.

To empty and delete the Amazon S3 bucket

  1. Open the Amazon S3 console.

  2. In the navigation pane on the left side of the console, choose Buckets.

  3. In the Buckets list, select the option next to the name of the bucket that you created for this tutorial, and then choose Empty.

  4. On the Empty bucket page, confirm that you want to empty the bucket by typing permanently delete into the text field, and then choose Empty.

  5. Monitor the progress of the bucket emptying process on the Empty bucket: Status page.

  6. To return to your bucket list, choose Exit.

  7. Select the option next to the name of the bucket, and then choose Delete.

  8. When prompted for confirmation, type the name of the bucket and then choose Delete bucket.

  9. Monitor the progress of the bucket deletion process from the Buckets list. When Amazon S3 completes the deletion of the bucket, it removes the bucket from the list.

Next steps

Congratulations! You successfully created a stack, monitored its creations, and used its output. To learn more about templates so that you can create your own, see Working with CloudFormation templates.

For additional walkthroughs that focus on more complex examples of using CloudFormation, see CloudFormation walkthroughs.