To connect an API Gateway to an inline Lambda function using CloudFormation, you can follow these steps:
- Define your API Gateway and Lambda function resources in your CloudFormation template. Here’s an example:
Resources:
MyApiGateway:
Type: AWS::ApiGateway::RestApi
Properties:
Name: MyApiGateway
MyApiGatewayResource:
Type: AWS::ApiGateway::Resource
Properties:
RestApiId: !Ref MyApiGateway
ParentId: !GetAtt MyApiGateway.RootResourceId
PathPart: myresource
MyApiGatewayMethod:
Type: AWS::ApiGateway::Method
Properties:
RestApiId: !Ref MyApiGateway
ResourceId: !Ref MyApiGatewayResource
HttpMethod: GET
AuthorizationType: NONE
Integration:
Type: AWS_PROXY
IntegrationHttpMethod: POST
Uri: !Sub "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:function:MyLambdaFunction/invocations"
MyApiGatewayDeployment:
Type: AWS::ApiGateway::Deployment
Properties:
RestApiId: !Ref MyApiGateway
MyApiGatewayStage:
Type: AWS::ApiGateway::Stage
Properties:
StageName: prod
RestApiId: !Ref MyApiGateway
DeploymentId: !Ref MyApiGatewayDeployment
MyLambdaFunction:
Type: AWS::Lambda::Function
Properties:
FunctionName: MyLambdaFunction
Runtime: python3.8
Handler: index.lambda_handler
Code:
ZipFile: |
def lambda_handler(event, context):
return {
'statusCode': 200,
'body': 'Hello from Lambda!'
}
In the above example, the Lambda function is defined inline using the ZipFile property. The code inside the lambda_handler function can be customized according to your requirements.
- Add the necessary permission for API Gateway to invoke the Lambda function:
MyLambdaPermission:
Type: AWS::Lambda::Permission
Properties:
FunctionName: !GetAtt MyLambdaFunction.Arn
Action: lambda:InvokeFunction
Principal: apigateway.amazonaws.com
SourceArn: !Sub "arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${MyApiGateway}/*/*/*"
- Deploy your API Gateway:
MyApiGatewayDeployment:
Type: AWS::ApiGateway::Deployment
Properties:
RestApiId: !Ref MyApiGateway
- Associate the deployment with a stage (e.g., “prod”):
MyApiGatewayStage:
Type: AWS::ApiGateway::Stage
Properties:
StageName: prod
RestApiId: !Ref MyApiGateway
DeploymentId: !Ref MyApiGatewayDeployment
- After defining these resources, you can deploy your CloudFormation stack using the AWS CloudFormation service or the AWS CLI.
These steps will create an API Gateway that is connected to your inline Lambda function. Requests made to the API Gateway endpoint will be routed to your Lambda function for processing.