(aws-cdk-lib): CloudFormation support for SNS platform application

[petro2050]

Describe the feature

Last time I checked CDK did not support CfnPlatformApplication and using something like a custom resource was suggested as an alternative. Is it possible to introduce a new construct so I can remove the custom resource? It should have API parity with CreatePlatformApplication.

Use Case

More infrastructure code can be defined in CDK removing the need for a custom resource and introducing failure points with custom resource lifecycle management.

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

AWS CDK Library version (aws-cdk-lib)

2.234.1

AWS CDK CLI version

2.1100.1

Environment details (OS name and version, etc.)

NA

[pahud]

Hi @petro2050,

Thank you for submitting this feature request!

Based on my investigation, this appears to be blocked by an upstream dependency on AWS CloudFormation. Currently, CloudFormation does not support AWS::SNS::PlatformApplication as a resource type. The official CloudFormation SNS documentation only lists the following resources:

• AWS::SNS::Subscription
• AWS::SNS::Topic
• AWS::SNS::TopicInlinePolicy
• AWS::SNS::TopicPolicy
  Since CDK's L1 constructs (like CfnPlatformApplication) are auto-generated from CloudFormation resource specifications, we cannot add support for this resource until CloudFormation adds it first.
  Upstream Issue: There is an existing feature request tracking this in the CloudFormation Coverage Roadmap:
• aws-cloudformation/cloudformation-coverage-roadmap#148 - "SNS Mobile push notifications - Platform applications" (open since August 2019, 12 upvotes)

I would encourage you to upvote (👍) and comment on that issue to increase its visibility with the CloudFormation team.

Once CloudFormation adds support for AWS::SNS::PlatformApplication, CDK will automatically generate the L1 construct, and we could then consider adding an L2 construct with a better developer experience. PRs are always welcome!