Lambda proxy integration ApiGateway (AWS)

09 Apr, 2023

Cloud formation template to create a Lambda proxy integration via ApiGateway. Lambda ARN should be provided, permission to invoke Lambda by ApiGateway is done in the template

Parameters:
    VPCId:
        Type: String
        Default: vpc-2785cc5d
    VPCEndpointId:
        Type: String
        Default: vpce-0c10a3cb8a0379f5f
    LambdaArn: 
        Type: String
        Default: arn:aws:lambda:us-east-1:597487947530:function:rest 

Resources:
    RestApi:
        Type: AWS::ApiGateway::RestApi
        Properties:
            EndpointConfiguration:
                Types:
                    - REGIONAL
            Name: testApi
            Policy: !Sub |
                        {
                            "Version": "2012-10-17",
                            "Statement": [
                                {
                                    "Effect": "Allow",
                                    "Principal": "*",
                                    "Action": "execute-api:Invoke",
                                    "Resource": "execute-api:/*"
                                }
                            ]
                        }

    MockMethod:
        Type: AWS::ApiGateway::Method
        Properties:
          RestApiId: !Ref RestApi
          ResourceId: !GetAtt RestApi.RootResourceId
          HttpMethod: POST
          AuthorizationType: NONE
          Integration:
            Type: AWS_PROXY
            IntegrationHttpMethod: POST
            Uri: !Sub arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${LambdaArn}/invocations
            IntegrationResponses:
              - StatusCode: 200
            PassthroughBehavior: WHEN_NO_MATCH
    
    Deployment:
      Type: AWS::ApiGateway::Deployment
      DependsOn: MockMethod
      Properties:
        RestApiId: !Ref RestApi
        Description: VPC endpoint test
        StageName: test

    InvokePermission:
        Type: AWS::Lambda::Permission
        Properties:
          Action: lambda:InvokeFunction
          FunctionName: !Ref LambdaArn
          Principal: "apigateway.amazonaws.com"
          SourceArn: !Sub "arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${RestApi}/*/POST/"