chore(aws-cdk-lib): airlift stable custom resource handlers only (#27101

)

Experimental custom resource handlers should be airlifted to their experimental modules only.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/custom-resource-handlers/README.md

@@ -2,14 +2,33 @@
 
 This package contains the following custom resource handlers:
 
+Stable:
+
 - aws-s3/auto-delete-objects-handler
 - aws-ecr/auto-delete-images-handler
+- aws-events-targets/aws-api-handler
+- custom-resources/aws-custom-resource-handler
+
+These handlers are copied into `aws-cdk-lib/custom-resource-handlers` at build time
+and included as part of the `aws-cdk-lib` package.
+
+Experimental:
+
 - aws-synthetics-alpha/auto-delete-underlying-resources-handler
 
-In addition, it includes `nodejs-entrypoint.ts`, which is a wrapper that talks to
+These handlers are excluded from `aws-cdk-lib/custom-resource-handlers` and are individually
+copied into their respective `-alpha` packages at build time. When an `-alpha` package is
+stabilized, part of the stabilization process **must** be to remove `-alpha` from the folder
+name, so that it is included in `aws-cdk-lib`.
+
+## Nodejs Entrypoint
+
+This package also includes `nodejs-entrypoint.ts`, which is a wrapper that talks to
 CloudFormation for you. At build time, `nodejs-entrypoint.js` is bundled into the
 `.js` file of the custom resource handler, creating one `index.js` file. This file
 is then either copied into a CDK asset or copied as inline code directly in the
 CloudFormation template.
 
+## Future Work
+
 In the future this package will contain all custom resources and their tests.

packages/aws-cdk-lib/scripts/airlift-custom-resource-handlers.sh

@@ -4,13 +4,13 @@ scriptdir=$(cd $(dirname $0) && pwd)
 customresourcedir=$(node -p "path.dirname(require.resolve('@aws-cdk/custom-resource-handlers/package.json'))")
 awscdklibdir=${scriptdir}/..
 
-list_custom_resources() {
-  for file in $customresourcedir/dist/*/*/index.js; do
+list_stable_custom_resources() {
+  for file in $customresourcedir/dist/*[^-alpha]/*/index.js; do
     echo $file | rev | cut -d "/" -f 2-4 | rev
   done
 }
 
-customresources=$(list_custom_resources)
+customresources=$(list_stable_custom_resources)
 
 echo $customresources