AWS::ApiGateway::Method is delete in every deployment

Question

I had a codepipeline with a cloudformation template. I'm creating a AWS::ApiGateway::Resource and AWS::ApiGateway::Method to access S3 bucket. First time it creates the method with the API. But when I push a change to the repo and it does a redeploy the method is deleted.

I can't which is the reason. Somebody has any clue! Thanks!

QrResource:
    Type: "AWS::ApiGateway::Resource"
    Properties:
      ParentId:
        Fn::GetAtt:
          - "myApi"
          - "RootResourceId"
      RestApiId: !Ref myApi
      PathPart: "qr"
  QrItemResource:
    Type: "AWS::ApiGateway::Resource"
    Properties:
      ParentId: !Ref QrResource
      RestApiId: !Ref myApi
      PathPart: "{item}"
  Qr:
    Type: "AWS::ApiGateway::Method"
    Properties:
      HttpMethod: GET
      ApiKeyRequired: false
      AuthorizationType: NONE
      RequestParameters:
        method.request.header.Content-Disposition: false
        method.request.header.Content-Type: false
        method.request.header.Accept: false
        method.request.path.item: true
      MethodResponses:
        - StatusCode: 200
          ResponseParameters:
            method.response.header.Content-Type: integration.response.header.Content-Type
            method.response.header.Content-Disposition: integration.response.header.Content-Disposition
            method.response.header.Accept-Ranges: integration.response.header.Accept-Ranges
          ResponseModels:
            "application/json": EmptyModel
        - StatusCode: 403
          ResponseModels:
            "application/json": ErrorModel
      RestApiId: !Ref myApi
      ResourceId: !Ref QrItemResource
      Integration:
        Type: AWS
        Credentials: !Ref RoleApi
        IntegrationHttpMethod: GET
        PassthroughBehavior: WHEN_NO_MATCH
        IntegrationResponses:
          - StatusCode: 200
            SelectionPattern: 200
            ContentHandling: CONVERT_TO_BINARY
            ResponseParameters:
              method.response.header.Content-Type: integration.response.header.Content-Type
              method.response.header.Accept-Ranges: "'bytes'"
              method.response.header.Content-Disposition: "'inline'"
            ResponseTemplates:
              "application/json": ""
        RequestParameters:
          integration.request.header.Content-Disposition: method.request.header.Content-Disposition
          integration.request.header.Content-Type: method.request.header.Content-Type
          integration.request.header.Accept: method.request.header.Accept
          integration.request.path.item: method.request.path.item
        Uri: arn:aws:apigateway:us-east-1:s3:path/s3-bucket/{item}

Answer 1

I had the same issue, so I opened a ticket in AWS Support. This was their answer:

Customer is using Serverless Application Model(SAM) (AWS::Serverless::Api+AWS::Serverless::Function) resources along with API Gateway CFN Resources (AWS::ApiGateway::Method) to define their API. 
This can have unpredictable situation where first can overwrite the second. We highly recommend customer to define this new resources in SAM directly under AWS::Serverless::Api as part of OpenApi. 

First, I considered this a bug since having unpredictable situations where first can overwrite the second doesn't seem like the desired behaviour for anyone.

But later on, they explained to me that the AWS::Serverless::Api creates all the necessary resources (like AWS::APIGateway::RestApi) to wire everything up.

So, if you're pushing a change where all the resources (AWS::Serverless::Api, AWS::ApiGateway::Resource and AWS::ApiGateway::Method) are being modified, Cloudformation will apply these changes in the OpenAPI definition, and everything will work as expected.

On the other hand, if you're pushing a change in the AWS::Serverless::Api (like adding an AWS::Serverless::Function attached to the AWS::Serverless::Api), Cloudformation will detect no changes on the AWS::ApiGateway::Resource and AWS::ApiGateway::Method (so the AWS::Serverless::Api OpenAPI definition will overwrite your standalone methods and path).

It seems like they have no way to check these conflicts on their side, which makes a little more sense.

So, in the end, the solution is not to mix AWS::Serverless::Api with standalone AWS::ApiGateway resources (like AWS::ApiGateway::Method and AWS::ApiGateway::Resource).

In fact, they told me they're about to update their documentation to add this recommendation. (it seems like it's not been pushed yet, but we can find the documentation history here)