There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.
# API Gateway examples using SDK for Python (Boto3)
The following code examples show you how to perform actions and implement common scenarios by using the AWS SDK for Python (Boto3) with API Gateway.
*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.
Each example includes a link to the complete source code, where you can find instructions on how to set up and run the code in context.
**Topics**
+ [Actions](#actions)
+ [Scenarios](#scenarios)
## Actions
### `CreateDeployment`
The following code example shows how to use `CreateDeployment`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def deploy_api(self, stage_name):
"""
Deploys a REST API. After a REST API is deployed, it can be called from any
REST client, such as the Python Requests package or Postman.
:param stage_name: The stage of the API to deploy, such as 'test'.
:return: The base URL of the deployed REST API.
"""
try:
self.apig_client.create_deployment(
restApiId=self.api_id, stageName=stage_name
)
self.stage = stage_name
logger.info("Deployed stage %s.", stage_name)
except ClientError:
logger.exception("Couldn't deploy stage %s.", stage_name)
raise
else:
return self.api_url()
def api_url(self, resource=None):
"""
Builds the REST API URL from its parts.
:param resource: The resource path to append to the base URL.
:return: The REST URL to the specified resource.
"""
url = (
f"https://{self.api_id}.execute-api.{self.apig_client.meta.region_name}"
f".amazonaws.com/{self.stage}"
)
if resource is not None:
url = f"{url}/{resource}"
return url
```
+ For API details, see [CreateDeployment](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateDeployment) in *AWS SDK for Python (Boto3) API Reference*.
### `CreateResource`
The following code example shows how to use `CreateResource`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def add_rest_resource(self, parent_id, resource_path):
"""
Adds a resource to a REST API.
:param parent_id: The ID of the parent resource.
:param resource_path: The path of the new resource, relative to the parent.
:return: The ID of the new resource.
"""
try:
result = self.apig_client.create_resource(
restApiId=self.api_id, parentId=parent_id, pathPart=resource_path
)
resource_id = result["id"]
logger.info("Created resource %s.", resource_path)
except ClientError:
logger.exception("Couldn't create resource %s.", resource_path)
raise
else:
return resource_id
```
+ For API details, see [CreateResource](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateResource) in *AWS SDK for Python (Boto3) API Reference*.
### `CreateRestApi`
The following code example shows how to use `CreateRestApi`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def create_rest_api(self, api_name):
"""
Creates a REST API on API Gateway. The default API has only a root resource
and no HTTP methods.
:param api_name: The name of the API. This descriptive name is not used in
the API path.
:return: The ID of the newly created API.
"""
try:
result = self.apig_client.create_rest_api(name=api_name)
self.api_id = result["id"]
logger.info("Created REST API %s with ID %s.", api_name, self.api_id)
except ClientError:
logger.exception("Couldn't create REST API %s.", api_name)
raise
try:
result = self.apig_client.get_resources(restApiId=self.api_id)
self.root_id = next(
item for item in result["items"] if item["path"] == "/"
)["id"]
except ClientError:
logger.exception("Couldn't get resources for API %s.", self.api_id)
raise
except StopIteration as err:
logger.exception("No root resource found in API %s.", self.api_id)
raise ValueError from err
return self.api_id
```
+ For API details, see [CreateRestApi](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateRestApi) in *AWS SDK for Python (Boto3) API Reference*.
### `DeleteRestApi`
The following code example shows how to use `DeleteRestApi`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def delete_rest_api(self):
"""
Deletes a REST API, including all of its resources and configuration.
"""
try:
self.apig_client.delete_rest_api(restApiId=self.api_id)
logger.info("Deleted REST API %s.", self.api_id)
self.api_id = None
except ClientError:
logger.exception("Couldn't delete REST API %s.", self.api_id)
raise
```
+ For API details, see [DeleteRestApi](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/DeleteRestApi) in *AWS SDK for Python (Boto3) API Reference*.
### `GetResources`
The following code example shows how to use `GetResources`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def create_rest_api(self, api_name):
"""
Creates a REST API on API Gateway. The default API has only a root resource
and no HTTP methods.
:param api_name: The name of the API. This descriptive name is not used in
the API path.
:return: The ID of the newly created API.
"""
try:
result = self.apig_client.create_rest_api(name=api_name)
self.api_id = result["id"]
logger.info("Created REST API %s with ID %s.", api_name, self.api_id)
except ClientError:
logger.exception("Couldn't create REST API %s.", api_name)
raise
try:
result = self.apig_client.get_resources(restApiId=self.api_id)
self.root_id = next(
item for item in result["items"] if item["path"] == "/"
)["id"]
except ClientError:
logger.exception("Couldn't get resources for API %s.", self.api_id)
raise
except StopIteration as err:
logger.exception("No root resource found in API %s.", self.api_id)
raise ValueError from err
return self.api_id
```
+ For API details, see [GetResources](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/GetResources) in *AWS SDK for Python (Boto3) API Reference*.
### `GetRestApis`
The following code example shows how to use `GetRestApis`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def get_rest_api_id(self, api_name):
"""
Gets the ID of a REST API from its name by searching the list of REST APIs
for the current account. Because names need not be unique, this returns only
the first API with the specified name.
:param api_name: The name of the API to look up.
:return: The ID of the specified API.
"""
try:
rest_api = None
paginator = self.apig_client.get_paginator("get_rest_apis")
for page in paginator.paginate():
rest_api = next(
(item for item in page["items"] if item["name"] == api_name), None
)
if rest_api is not None:
break
self.api_id = rest_api["id"]
logger.info("Found ID %s for API %s.", rest_api["id"], api_name)
except ClientError:
logger.exception("Couldn't find ID for API %s.", api_name)
raise
else:
return rest_api["id"]
```
+ For API details, see [GetRestApis](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/GetRestApis) in *AWS SDK for Python (Boto3) API Reference*.
### `PutIntegration`
The following code example shows how to use `PutIntegration`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def add_integration_method(
self,
resource_id,
rest_method,
service_endpoint_prefix,
service_action,
service_method,
role_arn,
mapping_template,
):
"""
Adds an integration method to a REST API. An integration method is a REST
resource, such as '/users', and an HTTP verb, such as GET. The integration
method is backed by an AWS service, such as Amazon DynamoDB.
:param resource_id: The ID of the REST resource.
:param rest_method: The HTTP verb used with the REST resource.
:param service_endpoint_prefix: The service endpoint that is integrated with
this method, such as 'dynamodb'.
:param service_action: The action that is called on the service, such as
'GetItem'.
:param service_method: The HTTP method of the service request, such as POST.
:param role_arn: The Amazon Resource Name (ARN) of a role that grants API
Gateway permission to use the specified action with the
service.
:param mapping_template: A mapping template that is used to translate REST
elements, such as query parameters, to the request
body format required by the service.
"""
service_uri = (
f"arn:aws:apigateway:{self.apig_client.meta.region_name}"
f":{service_endpoint_prefix}:action/{service_action}"
)
try:
self.apig_client.put_method(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
authorizationType="NONE",
)
self.apig_client.put_method_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseModels={"application/json": "Empty"},
)
logger.info("Created %s method for resource %s.", rest_method, resource_id)
except ClientError:
logger.exception(
"Couldn't create %s method for resource %s.", rest_method, resource_id
)
raise
try:
self.apig_client.put_integration(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
type="AWS",
integrationHttpMethod=service_method,
credentials=role_arn,
requestTemplates={"application/json": json.dumps(mapping_template)},
uri=service_uri,
passthroughBehavior="WHEN_NO_TEMPLATES",
)
self.apig_client.put_integration_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseTemplates={"application/json": ""},
)
logger.info(
"Created integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
except ClientError:
logger.exception(
"Couldn't create integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
raise
```
+ For API details, see [PutIntegration](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutIntegration) in *AWS SDK for Python (Boto3) API Reference*.
### `PutIntegrationResponse`
The following code example shows how to use `PutIntegrationResponse`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def add_integration_method(
self,
resource_id,
rest_method,
service_endpoint_prefix,
service_action,
service_method,
role_arn,
mapping_template,
):
"""
Adds an integration method to a REST API. An integration method is a REST
resource, such as '/users', and an HTTP verb, such as GET. The integration
method is backed by an AWS service, such as Amazon DynamoDB.
:param resource_id: The ID of the REST resource.
:param rest_method: The HTTP verb used with the REST resource.
:param service_endpoint_prefix: The service endpoint that is integrated with
this method, such as 'dynamodb'.
:param service_action: The action that is called on the service, such as
'GetItem'.
:param service_method: The HTTP method of the service request, such as POST.
:param role_arn: The Amazon Resource Name (ARN) of a role that grants API
Gateway permission to use the specified action with the
service.
:param mapping_template: A mapping template that is used to translate REST
elements, such as query parameters, to the request
body format required by the service.
"""
service_uri = (
f"arn:aws:apigateway:{self.apig_client.meta.region_name}"
f":{service_endpoint_prefix}:action/{service_action}"
)
try:
self.apig_client.put_method(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
authorizationType="NONE",
)
self.apig_client.put_method_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseModels={"application/json": "Empty"},
)
logger.info("Created %s method for resource %s.", rest_method, resource_id)
except ClientError:
logger.exception(
"Couldn't create %s method for resource %s.", rest_method, resource_id
)
raise
try:
self.apig_client.put_integration(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
type="AWS",
integrationHttpMethod=service_method,
credentials=role_arn,
requestTemplates={"application/json": json.dumps(mapping_template)},
uri=service_uri,
passthroughBehavior="WHEN_NO_TEMPLATES",
)
self.apig_client.put_integration_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseTemplates={"application/json": ""},
)
logger.info(
"Created integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
except ClientError:
logger.exception(
"Couldn't create integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
raise
```
+ For API details, see [PutIntegrationResponse](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutIntegrationResponse) in *AWS SDK for Python (Boto3) API Reference*.
### `PutMethod`
The following code example shows how to use `PutMethod`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def add_integration_method(
self,
resource_id,
rest_method,
service_endpoint_prefix,
service_action,
service_method,
role_arn,
mapping_template,
):
"""
Adds an integration method to a REST API. An integration method is a REST
resource, such as '/users', and an HTTP verb, such as GET. The integration
method is backed by an AWS service, such as Amazon DynamoDB.
:param resource_id: The ID of the REST resource.
:param rest_method: The HTTP verb used with the REST resource.
:param service_endpoint_prefix: The service endpoint that is integrated with
this method, such as 'dynamodb'.
:param service_action: The action that is called on the service, such as
'GetItem'.
:param service_method: The HTTP method of the service request, such as POST.
:param role_arn: The Amazon Resource Name (ARN) of a role that grants API
Gateway permission to use the specified action with the
service.
:param mapping_template: A mapping template that is used to translate REST
elements, such as query parameters, to the request
body format required by the service.
"""
service_uri = (
f"arn:aws:apigateway:{self.apig_client.meta.region_name}"
f":{service_endpoint_prefix}:action/{service_action}"
)
try:
self.apig_client.put_method(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
authorizationType="NONE",
)
self.apig_client.put_method_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseModels={"application/json": "Empty"},
)
logger.info("Created %s method for resource %s.", rest_method, resource_id)
except ClientError:
logger.exception(
"Couldn't create %s method for resource %s.", rest_method, resource_id
)
raise
try:
self.apig_client.put_integration(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
type="AWS",
integrationHttpMethod=service_method,
credentials=role_arn,
requestTemplates={"application/json": json.dumps(mapping_template)},
uri=service_uri,
passthroughBehavior="WHEN_NO_TEMPLATES",
)
self.apig_client.put_integration_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseTemplates={"application/json": ""},
)
logger.info(
"Created integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
except ClientError:
logger.exception(
"Couldn't create integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
raise
```
+ For API details, see [PutMethod](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutMethod) in *AWS SDK for Python (Boto3) API Reference*.
### `PutMethodResponse`
The following code example shows how to use `PutMethodResponse`.
**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/api-gateway#code-examples).
```
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def add_integration_method(
self,
resource_id,
rest_method,
service_endpoint_prefix,
service_action,
service_method,
role_arn,
mapping_template,
):
"""
Adds an integration method to a REST API. An integration method is a REST
resource, such as '/users', and an HTTP verb, such as GET. The integration
method is backed by an AWS service, such as Amazon DynamoDB.
:param resource_id: The ID of the REST resource.
:param rest_method: The HTTP verb used with the REST resource.
:param service_endpoint_prefix: The service endpoint that is integrated with
this method, such as 'dynamodb'.
:param service_action: The action that is called on the service, such as
'GetItem'.
:param service_method: The HTTP method of the service request, such as POST.
:param role_arn: The Amazon Resource Name (ARN) of a role that grants API
Gateway permission to use the specified action with the
service.
:param mapping_template: A mapping template that is used to translate REST
elements, such as query parameters, to the request
body format required by the service.
"""
service_uri = (
f"arn:aws:apigateway:{self.apig_client.meta.region_name}"
f":{service_endpoint_prefix}:action/{service_action}"
)
try:
self.apig_client.put_method(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
authorizationType="NONE",
)
self.apig_client.put_method_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseModels={"application/json": "Empty"},
)
logger.info("Created %s method for resource %s.", rest_method, resource_id)
except ClientError:
logger.exception(
"Couldn't create %s method for resource %s.", rest_method, resource_id
)
raise
try:
self.apig_client.put_integration(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
type="AWS",
integrationHttpMethod=service_method,
credentials=role_arn,
requestTemplates={"application/json": json.dumps(mapping_template)},
uri=service_uri,
passthroughBehavior="WHEN_NO_TEMPLATES",
)
self.apig_client.put_integration_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseTemplates={"application/json": ""},
)
logger.info(
"Created integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
except ClientError:
logger.exception(
"Couldn't create integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
raise
```
+ For API details, see [PutMethodResponse](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutMethodResponse) in *AWS SDK for Python (Boto3) API Reference*.
## Scenarios
### Create a REST API to track COVID-19 data
The following code example shows how to create a REST API that simulates a system to track daily cases of COVID-19 in the United States, using fictional data.
**SDK for Python (Boto3)**
Shows how to use AWS Chalice with the AWS SDK for Python (Boto3) to create a serverless REST API that uses Amazon API Gateway, AWS Lambda, and Amazon DynamoDB. The REST API simulates a system that tracks daily cases of COVID-19 in the United States, using fictional data. Learn how to:
+ Use AWS Chalice to define routes in Lambda functions that are called to handle REST requests that come through API Gateway.
+ Use Lambda functions to retrieve and store data in a DynamoDB table to serve REST requests.
+ Define table structure and security role resources in an AWS CloudFormation template.
+ Use AWS Chalice and CloudFormation to package and deploy all necessary resources.
+ Use CloudFormation to clean up all created resources.
For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/apigateway_covid-19_tracker).
**Services used in this example**
+ API Gateway
+ CloudFormation
+ DynamoDB
+ Lambda
### Create a lending library REST API
The following code example shows how to create a lending library where patrons can borrow and return books by using a REST API backed by an Amazon Aurora database.
**SDK for Python (Boto3)**
Shows how to use the AWS SDK for Python (Boto3) with the Amazon Relational Database Service (Amazon RDS) API and AWS Chalice to create a REST API backed by an Amazon Aurora database. The web service is fully serverless and represents a simple lending library where patrons can borrow and return books. Learn how to:
+ Create and manage a serverless Aurora database cluster.
+ Use AWS Secrets Manager to manage database credentials.
+ Implement a data storage layer that uses Amazon RDS to move data into and out of the database.
+ Use AWS Chalice to deploy a serverless REST API to Amazon API Gateway and AWS Lambda.
+ Use the Requests package to send requests to the web service.
For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/aurora_rest_lending_library).
**Services used in this example**
+ API Gateway
+ Aurora
+ Lambda
+ Secrets Manager
### Create a websocket chat application
The following code example shows how to create a chat application that is served by a websocket API built on Amazon API Gateway.
**SDK for Python (Boto3)**
Shows how to use the AWS SDK for Python (Boto3) with Amazon API Gateway V2 to create a websocket API that integrates with AWS Lambda and Amazon DynamoDB.
+ Create a websocket API served by API Gateway.
+ Define a Lambda handler that stores connections in DynamoDB and posts messages to other chat participants.
+ Connect to the websocket chat application and send messages with the Websockets package.
For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/apigateway_websocket_chat).
**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
### Create and deploy a REST API
The following code example shows how to:
+ Create a REST API served by API Gateway.
+ Add resources to the REST API to represent a user profile.
+ Add integration methods so that the REST API uses a DynamoDB table to store user profile data.
+ Send HTTP requests to the REST API to add and retrieve user profiles.
**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/api-gateway#code-examples).
Create a class that wraps API Gateway operations.
```
import argparse
import json
import logging
from pprint import pprint
import boto3
from botocore.exceptions import ClientError
import requests
logger = logging.getLogger(__name__)
class ApiGatewayToService:
"""
Encapsulates Amazon API Gateway functions that are used to create a REST API that
integrates with another AWS service.
"""
def __init__(self, apig_client):
"""
:param apig_client: A Boto3 API Gateway client.
"""
self.apig_client = apig_client
self.api_id = None
self.root_id = None
self.stage = None
def create_rest_api(self, api_name):
"""
Creates a REST API on API Gateway. The default API has only a root resource
and no HTTP methods.
:param api_name: The name of the API. This descriptive name is not used in
the API path.
:return: The ID of the newly created API.
"""
try:
result = self.apig_client.create_rest_api(name=api_name)
self.api_id = result["id"]
logger.info("Created REST API %s with ID %s.", api_name, self.api_id)
except ClientError:
logger.exception("Couldn't create REST API %s.", api_name)
raise
try:
result = self.apig_client.get_resources(restApiId=self.api_id)
self.root_id = next(
item for item in result["items"] if item["path"] == "/"
)["id"]
except ClientError:
logger.exception("Couldn't get resources for API %s.", self.api_id)
raise
except StopIteration as err:
logger.exception("No root resource found in API %s.", self.api_id)
raise ValueError from err
return self.api_id
def add_rest_resource(self, parent_id, resource_path):
"""
Adds a resource to a REST API.
:param parent_id: The ID of the parent resource.
:param resource_path: The path of the new resource, relative to the parent.
:return: The ID of the new resource.
"""
try:
result = self.apig_client.create_resource(
restApiId=self.api_id, parentId=parent_id, pathPart=resource_path
)
resource_id = result["id"]
logger.info("Created resource %s.", resource_path)
except ClientError:
logger.exception("Couldn't create resource %s.", resource_path)
raise
else:
return resource_id
def add_integration_method(
self,
resource_id,
rest_method,
service_endpoint_prefix,
service_action,
service_method,
role_arn,
mapping_template,
):
"""
Adds an integration method to a REST API. An integration method is a REST
resource, such as '/users', and an HTTP verb, such as GET. The integration
method is backed by an AWS service, such as Amazon DynamoDB.
:param resource_id: The ID of the REST resource.
:param rest_method: The HTTP verb used with the REST resource.
:param service_endpoint_prefix: The service endpoint that is integrated with
this method, such as 'dynamodb'.
:param service_action: The action that is called on the service, such as
'GetItem'.
:param service_method: The HTTP method of the service request, such as POST.
:param role_arn: The Amazon Resource Name (ARN) of a role that grants API
Gateway permission to use the specified action with the
service.
:param mapping_template: A mapping template that is used to translate REST
elements, such as query parameters, to the request
body format required by the service.
"""
service_uri = (
f"arn:aws:apigateway:{self.apig_client.meta.region_name}"
f":{service_endpoint_prefix}:action/{service_action}"
)
try:
self.apig_client.put_method(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
authorizationType="NONE",
)
self.apig_client.put_method_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseModels={"application/json": "Empty"},
)
logger.info("Created %s method for resource %s.", rest_method, resource_id)
except ClientError:
logger.exception(
"Couldn't create %s method for resource %s.", rest_method, resource_id
)
raise
try:
self.apig_client.put_integration(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
type="AWS",
integrationHttpMethod=service_method,
credentials=role_arn,
requestTemplates={"application/json": json.dumps(mapping_template)},
uri=service_uri,
passthroughBehavior="WHEN_NO_TEMPLATES",
)
self.apig_client.put_integration_response(
restApiId=self.api_id,
resourceId=resource_id,
httpMethod=rest_method,
statusCode="200",
responseTemplates={"application/json": ""},
)
logger.info(
"Created integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
except ClientError:
logger.exception(
"Couldn't create integration for resource %s to service URI %s.",
resource_id,
service_uri,
)
raise
def deploy_api(self, stage_name):
"""
Deploys a REST API. After a REST API is deployed, it can be called from any
REST client, such as the Python Requests package or Postman.
:param stage_name: The stage of the API to deploy, such as 'test'.
:return: The base URL of the deployed REST API.
"""
try:
self.apig_client.create_deployment(
restApiId=self.api_id, stageName=stage_name
)
self.stage = stage_name
logger.info("Deployed stage %s.", stage_name)
except ClientError:
logger.exception("Couldn't deploy stage %s.", stage_name)
raise
else:
return self.api_url()
def api_url(self, resource=None):
"""
Builds the REST API URL from its parts.
:param resource: The resource path to append to the base URL.
:return: The REST URL to the specified resource.
"""
url = (
f"https://{self.api_id}.execute-api.{self.apig_client.meta.region_name}"
f".amazonaws.com/{self.stage}"
)
if resource is not None:
url = f"{url}/{resource}"
return url
```
Deploy a REST API and call it with the Requests package.
```
def usage_demo(table_name, role_name, rest_api_name):
"""
Demonstrates how to used API Gateway to create and deploy a REST API, and how
to use the Requests package to call it.
:param table_name: The name of the demo DynamoDB table.
:param role_name: The name of the demo role that grants API Gateway permission to
call DynamoDB.
:param rest_api_name: The name of the demo REST API created by the demo.
"""
gateway = ApiGatewayToService(boto3.client("apigateway"))
role = boto3.resource("iam").Role(role_name)
print("Creating REST API in API Gateway.")
gateway.create_rest_api(rest_api_name)
print("Adding resources to the REST API.")
profiles_id = gateway.add_rest_resource(gateway.root_id, "profiles")
username_id = gateway.add_rest_resource(profiles_id, "{username}")
# The DynamoDB service requires that all integration requests use POST.
print("Adding integration methods to read and write profiles in Amazon DynamoDB.")
gateway.add_integration_method(
profiles_id,
"GET",
"dynamodb",
"Scan",
"POST",
role.arn,
{"TableName": table_name},
)
gateway.add_integration_method(
profiles_id,
"POST",
"dynamodb",
"PutItem",
"POST",
role.arn,
{
"TableName": table_name,
"Item": {
"username": {"S": "$input.path('$.username')"},
"name": {"S": "$input.path('$.name')"},
"title": {"S": "$input.path('$.title')"},
},
},
)
gateway.add_integration_method(
username_id,
"GET",
"dynamodb",
"GetItem",
"POST",
role.arn,
{
"TableName": table_name,
"Key": {"username": {"S": "$method.request.path.username"}},
},
)
stage = "test"
print(f"Deploying the {stage} stage.")
gateway.deploy_api(stage)
profiles_url = gateway.api_url("profiles")
print(
f"Using the Requests package to post some people to the profiles REST API at "
f"{profiles_url}."
)
requests.post(
profiles_url,
json={"username": "will", "name": "William Shakespeare", "title": "playwright"},
)
requests.post(
profiles_url,
json={
"username": "ludwig",
"name": "Ludwig van Beethoven",
"title": "composer",
},
)
requests.post(
profiles_url,
json={"username": "jane", "name": "Jane Austen", "title": "author"},
)
print("Getting the list of profiles from the REST API.")
profiles = requests.get(profiles_url).json()
pprint(profiles)
print(f"Getting just the profile for username 'jane' (URL: {profiles_url}/jane).")
jane = requests.get(f"{profiles_url}/jane").json()
pprint(jane)
```
+ For API details, see the following topics in *AWS SDK for Python (Boto3) API Reference*.
+ [CreateDeployment](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateDeployment)
+ [CreateResource](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateResource)
+ [CreateRestApi](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateRestApi)
+ [DeleteRestApi](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/DeleteRestApi)
+ [GetResources](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/GetResources)
+ [GetRestApis](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/GetRestApis)
+ [PutIntegration](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutIntegration)
+ [PutIntegrationResponse](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutIntegrationResponse)
+ [PutMethod](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutMethod)
+ [PutMethodResponse](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutMethodResponse)
### Use API Gateway to invoke a Lambda function
The following code example shows how to create an AWS Lambda function invoked by Amazon API Gateway.
**SDK for Python (Boto3)**
This example shows how to create and use an Amazon API Gateway REST API that targets an AWS Lambda function. The Lambda handler demonstrates how to route based on HTTP methods; how to get data from the query string, header, and body; and how to return a JSON response.
+ Deploy a Lambda function.
+ Create an API Gateway REST API.
+ Create a REST resource that targets the Lambda function.
+ Grant permission to let API Gateway invoke the Lambda function.
+ Use the Requests package to send requests to the REST API.
+ Clean up all resources created during the demo.
This example is best viewed on GitHub. For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#readme).
**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon SNS