Support for HTTP API tagging

[farski]

Description:

I don't believe there is currently any way to add resource tags to an AWS::Serverless::HttpApi resource[1]. The SAM specification does not include anything, and I don't think it's possible to do it through an OpenAPI definition (though admittedly my experience with OpenAPI/Swagger is limited. I have read through the docs, specifically the info section, and did not find anything).

[1] It turns out you can add a tags list to the OpenApi BodyDefinition and those tags will get applied to the HttpApi, but they don't get applied to default stage, and there may be better ways of supporting tags, as discussed below.

[farski]

Digging into the code on this a bit (which is probably fraught because I've never looked at the SAM codebase before), it does appear as though there is some level of support for tags on AWS::Serverless::HttpApiresources here. The to_cloudformation function passes tags into the HttpApiGenerator.

Eventually the tags make their way to the open_api class and get added to the OpenApi definition as _X_APIGW_TAG_VALUE extensions.

In fact, the only way to get tags to work with an HTTP API is if the resource definition includes an inline DefinitionBody.

It doesn't seem like it's necessary to handle tagging this way, since the underlying AWS::ApiGatewayV2::Api resource natively supports tags, as does AWS::ApiGatewayV2::Stage.

So perhaps there is support for this already, but it's just not documented.

All that being said, when I try to deploy this SAM template…

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Resources:
  HttpApi:
    Type: AWS::Serverless::HttpApi
    Properties:
      Tags:
        TagName2: TagValue2

…it fails with the error Property validation failure: [Value of property {/Tags} does not match type {Map}], even though that should be treated as a Map. Alternatively, this CloudFormation template…

AWSTemplateFormatVersion: '2010-09-09'
Resources:
  HttpApi:
    Type: AWS::ApiGatewayV2::Api
    Properties:
      Name: TEST TEST
      Description: TEST TEST
      ProtocolType: HTTP
      Target: "https://www.example.com/"
      Tags:
        TagName1: TagValue1

…does work as expected. Which is to say AWS::ApiGatewayV2::Api supports tagging, but in a somewhat non-standard way (nearly all CloudFormation resources use the Resource Tag property to add tags, not a straight key-value pair). Regardless, it seems like the transform could be done that way, rather than injecting the tags into the DefinitionBody as is being done now.

[adrai]

fyi: at least in DefinitionBody it seems to work:

[farski]

@adrai Yes that does work, but as I mentioned it doesn't trickle down to the $default stage, which make that more or less untaggable.

[keetonian]

@farski we're working on Http Api features for this next release, and adding tags to this resource (utilizing OpenApi) is a new feature. I like the suggestion passing through these tags to the Stage resource.

[ShreyaGangishetty]

This is released in v1.22.0