Serverless-application-model: AWS::Serverless::Api Property "RestApiId" does not support If, Map Functions

[colinbjohnson]

Description:

The AWS::Serverless::Api does not support particular functions such as Fn::If and Fn::FindInMap. My use case is that particular AWS::Serverless::Function resources my SAM template may have events coming from different API Gateways depending on a parameter I pass in.

Steps to reproduce the issue:

Given the following template:

AWSTemplateFormatVersion: '2010-09-09'

Transform: AWS::Serverless-2016-10-31

Conditions:

  IsProd:
    Fn::Equals:
      - !Ref Environment
      - prod

Parameters:

    Environment:
      Type: String
      Default: prod
      AllowedValues: 
        - prod

Description: >
  sam-app

  Sample SAM Template for sam-app

Globals:
  Function:
    Timeout: 3

Resources:

  PublicAWSApiGateway:
    Type: AWS::Serverless::Api
    Properties:
      Name: Public AWS Api Gateway
      StageName: Staging

  PrivateAWSApiGateway:
    Type: AWS::Serverless::Api
    Properties:
      Name: Private AWS Api Gateway
      StageName: Staging

  HelloWorldFunctionPrivate:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: hello_world/
      Handler: app.lambda_handler
      Runtime: python3.8
      Events:
        HelloWorld:
          Type: Api
          Properties:
            Path: /hello
            Method: get
            RestApiId: !If [ IsProd, !Ref PublicAWSApiGateway, !Ref PrivateAWSApiGateway ]

Outputs: {}

Run the command:

sam validate --debug

Observed result:

The following result is returned:

Error: [InvalidResourceException('HelloWorldFunctionPrivate', 'Event with id [HelloWorld] is invalid. Api Event must reference an Api in the same template.'), InvalidResourceException('HelloWorldFunctionPublic', 'Event with id [HelloWorld] is invalid. Api Event must reference an Api in the same template.')] ('HelloWorldFunctionPrivate', 'Event with id [HelloWorld] is invalid. Api Event must reference an Api in the same template.') ('HelloWorldFunctionPublic', 'Event with id [HelloWorld] is invalid. Api Event must reference an Api in the same template.')

Expected result:

1. Expected result is that the given AWS::Serverless::Function would be associated with the given API Gateway returned by the If or FindInMap function.

[ShreyaGangishetty]

Thanks for the feature request! We have passed this along to our product team for possible prioritization. Please +1 on the feature to help with prioritization.

[ayozemr]

I was going crazy with this error until found this issue... Thanks for looking into it!

[sandun-rezg]

I have the same issue.
RestApiId property of Api event must reference a valid resource in the same template.
Any update on this issue?

[si3mshady]

I am unable to import an exported RestApi from a CFN template to a SAM template (which is CFN under the hood)

Stack A - excerpt

Outputs:
SandboxApiOutput:
Description: Description of value to be outputted
Value: !Ref booksapiE1885304
Export:
Name: "BookAPI-Reference-for-lambda-function"

Stack B - excerpt

MyLambda:
Type: AWS::Serverless::Function
Properties:
FunctionName: I-DID-IT-MyLambda
Handler: index.Handler
# CodeUri:
Events:
MyLambda:
Type: Api
Properties:
Path: /example
Method: post
RestApiId:
Fn::ImportValue:
"BookAPI-Reference-for-lambda-function"

Error Message ->
[InvalidResourceException('MyLambda', 'Event with id [MyLambda] is invalid. Api Event must reference an Api in the same template.')] ('MyLambda', 'Event with id [MyLambda] is invalid. Api Event must reference an Api in the same template.')