lambda: add removalPolicy option to LayerVersionPermission

[lewesche]

Describe the feature

Change LayerVersionPermission to take a optional RemovalPolicy

Use Case

My use case involves publishing a lambda layer consumed by a library. Users may be on different library versions, meaning they may be on different layer versions. These users need to be able to access the layer from different accounts across my organization.

At first I added resource permissions to the layer by calling ILayerVersion.addPermission(). However I noticed that when new layers were published, old layers lost their resource permissions. I confirmed this with the cli: aws lambda get-layer-version-policy --layer-name ... --version-number ....

Looking at the I was able to fix the behavior by manually constructing the CfnLayerVersionPermission instead of using the top level addPermission() function:

    const orgPermission = new CfnLayerVersionPermission(this, "qualtricsOrgPermissionAmd64", {
      action: 'lambda:GetLayerVersion',
      layerVersionArn: lambdaLayer.layerVersionArn,
      principal: '*',
      organizationId: constants.ORG_ID,
    });
    orgPermission.applyRemovalPolicy(cdk.RemovalPolicy.RETAIN);

This added "UpdateReplacePolicy": "Retain", "DeletionPolicy": "Retain" to the cloud formation template (according to this documentation, both are required). That fixed my issue but it's an ugly solution that was difficult to come up with. I'd like to be able to use addPermission().

Proposed Solution

I have a PR for it the change here, thanks! #30578

Other Information

No response

Acknowledgements

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

CDK version used

2.140.0

Environment details (OS name and version, etc.)

Mac OS 14.5 Sonoma