Translate local file strings to AWS::Include transform

[jdub]

There are quite a few issues on this repo related to variable substitution in separate YAML files, particularly dealing with x-amazon-apigateway-integration's uri parameter.

What if, instead of aws cloudformation package translating a local file string to an s3:// URI, it translated it to an AWS::Include transform?

This SAM / CloudFormation template:

Resources:
  Api:
    Properties:
      DefinitionUri: ./swagger.yaml

… currently translates to:

Resources:
  Api:
    Properties:
      DefinitionUri: s3://bucket/swagger.yaml

… but could instead translate to:

Resources:
  Api:
    Properties:
      DefinitionBody:
        Fn::Transform:
          Name: AWS::Include
          Parameters:
            Location: s3://bucket/swagger.yaml

[sanathkr]

I am not sure. Inlining swagger file has some limitations:

• Customers might run into their CloudFormation template size limitations
• You would include CloudFormation constructs (like intrinsics or resource names) in your Swagger file, which makes it harder to share with others

Instead, it would be better to extend aws cloudformation package command to support S3 upload functionality for AWS::Include property. Customers can then choose to use the Include style if they want.

What do you think? This should be simple change to make the CLI. Want to send a PR?

[jdub]

Ah, I didn't consider the template size limitations. That does make it awkward.

Unfortunately, using CloudFormation constructs was part of my goal. 😅

Right now, Swagger files need hard-coded Lambda Function ARNs in, for example, x-amazon-apigateway-integration.uri, which benefit greatly from AWS::Region and Function.Arn references:

paths:
  /debug:
    get:
      x-amazon-apigateway-integration:
        httpMethod: POST
        type: "aws_proxy"
        uri:
          Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${DebugFunction.Arn}/invocations
      responses: {}

[sanathkr]

Closing this because it has been out for a while without gathering much interests.

[ekcrisp]

@sanathkr

Instead, it would be better to extend aws cloudformation package command to support S3 upload functionality for AWS::Include property. Customers can then choose to use the Include style if they want.

any updates on this?

EDIT: I submitted a PR for this feature