ApiGateway Stage not recognises new lambda function on update when using OpenAPI definition

Question

Hi,

Im using Cloudformation to create my REST API (AWS::ApiGateway::RestApi) and defining the API itself using OpenAPI and adding it to the REST API with the BodyS3Location. I noticed if I set up a new endpoint in the OpenAPI yaml definition and update the stack the new endpoint will be added to the "Resources" but not to the stage. So currently if I have to add a new function to my API my only option is to recreate the whole API. Im pretty sure that I'm missing something but cannot figure out what, I cannot find any similar examples.

The corresponding part of my template:

```
Api:
    Type: AWS::ApiGateway::RestApi
    Properties:
      EndpointConfiguration:
        Types:
        - REGIONAL
      BodyS3Location: 
        Bucket: !Ref OpenApiBucket
        Key: !Ref OpenApiDefinitionPath

ApiDeployment:
    Type: AWS::ApiGateway::Deployment
    Properties:
      RestApiId: !Ref Api

ApiStage:
    Type: AWS::ApiGateway::Stage
    Properties: 
      MethodSettings:
        - DataTraceEnabled: true
          HttpMethod: "*"
          LoggingLevel: INFO
          ResourcePath: "/*"
          MetricsEnabled: true
      DeploymentId: !Ref ApiDeployment
      RestApiId: !Ref Api
      StageName: prod
      Variables:
        MyNewLambaFunctionARN: !Ref NewLambaFunctionARN
```

And my OpenAPI definitions are looking like this:

```
paths:
  /v1/mynewendpoint:
    ...
    post:
      x-amazon-apigateway-request-validator: all
      x-amazon-apigateway-integration:
        type: AWS_PROXY
        httpMethod: post
        uri: ${stageVariables.MyNewLambaFunctionARN}
      requestBody:
        content:
          application/json:
            schema:
              ....
      responses:
        ...
```

For the updates I upload the OpenApi definition with a new key to the bucket, and the call an update-stack operation using the key as a parameter. After the update is  using the console I can see the new method in the API's "Resources" tab but it will be not included under the "Stages" and the API will respond with an error message when I try to execute the request towards this endpoint.

What am I missing here?

Thanks in advance!

Peter

Answer

Hi

Thank you for you answer!

So I modified my 'AWS::ApiGateway::Deployment' to this:

```
  ApiDeployment:
    Type: AWS::ApiGateway::Deployment
    Properties:
      RestApiId: !Ref Api
      StageName: prod
```

But now during the update I get this error when CloudFormation tries to update the Deployment:

```
Resource handler returned message: "null" (RequestToken: , HandlerErrorCode: InternalFailure)
```

As it was not too descriptive I tried to recreate the whole stack, there I got this more verbose error message when it tries to create the Deployment:

```
Resource handler returned message: "Stage already exists (Service: ApiGateway, Status Code: 409, Request ID: , Extended Request ID: null)" (RequestToken: , HandlerErrorCode: AlreadyExists)
```

I tried to remove the 'StageName: prod' from the AWS::ApiGateway::Stage definition, but the simple update was failing that way too, so I recreated the whole stack again. This resulted that now I have two stages (I kinda expected that) but on update none of the two will be updated with the new enpoint

Answer

Do anyone has any idea how to solve this?

Or maybe this is something that is not supported by the API Gateway?

Answer

Try adding `StageName: prod` to the `ApiDeployment` section.

ApiGateway Stage not recognises new lambda function on update when using OpenAPI definition

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