I am using SAM to deploy a simple Hello world application. One with one API Endpoint, which will trigger a lambda function that returns the text hello world. I have defined the following resources:

1. IAM Role so that APIGateway can invoke lambda functions.
2. AWS::ApiGateway::RestApi
3. AWS::ApiGateway::Resource
4. AWS::ApiGateway::Method
5. AWS::Serverless::Function

Admittedly, I do not know the difference in functionality between 2. and 3. yet.

During sam deploy I see the following error.

ROLLBACK_IN_PROGRESS                              AWS::CloudFormation::Stack                        go-hello-world                                    The following resource(s) failed to create:     
                                                                                                                                                      [HelloWorldAPIResource,                         
                                                                                                                                                      HelloWorldFunctionRole]. Rollback requested by  
                                                                                                                                                      user.                                           
CREATE_FAILED                                     AWS::IAM::Role                                    HelloWorldFunctionRole                            Resource creation cancelled                     
CREATE_FAILED                                     AWS::ApiGateway::Resource                         HelloWorldAPIResource                             Resource handler returned message: "Invalid     
                                                                                                                                                      Resource identifier specified (Service:         
                                                                                                                                                      ApiGateway, Status Code: 404, Request ID:       
                                                                                                                                                      62f34d79-86ab-47fd-85b1-5fbb55071520, Extended  
                                                                                                                                                      Request ID: null)" (RequestToken:               
                                                                                                                                                      9633d7db-7b6d-881b-f54e-ca0114862fd8,           
                                                                                                                                                      HandlerErrorCode: NotFound)

Which means that the AWS::ApiGateway::Resource is not getting a valid reference to AWS::ApiGateway::RestApi.

Here is the relevant part from my template.yml

  HelloWorldAPI:
    Type: AWS::ApiGateway::RestApi
    Properties: 
      Name: HelloWorldApi

  HelloWorldAPIResource:
    Type: AWS::ApiGateway::Resource
    Properties:
      RestApiId: !Ref HelloWorldAPI
      ParentId: "/"
      PathPart: hello

I am new to both CloudFormation and AWS in general, any help is appreciated.

CodePudding user response：

It should be:

 ParentId: !GetAtt HelloWorldAPI.RootResourceId