Return concrete values for physical names and ARNs if explicitly stated

[eladb]

🚀 Feature Request

Description

When a user specified an explicit physical name for an AWS resource, the corresponding attributes should also return a concrete name.

For example, if I define a bucket with a bucketName:

const bucket = new s3.Bucket(this, 'MyBucket', { bucketName: 'hello' });

Then, I would expect bucket.bucketName to return hello and not a token that resolves to { "Fn::GetAtt": [ ... ] }

❗️There is a problem: CloudFormation references implicitly indicate that there is a dependency between the consuming resource and the referenced resource. If we return a concrete name (string), this dependency will now be lost forever. Is there anything we can do about it? (@rix0rrr?)

[rix0rrr]

Doesn't/shouldn't this already work today by means of the PhysicalName machinery? As in, if you specify a physicalName, then bucket.bucketName already returns the configured value?

If it doesn't work for some particular resource, it's a bug in the implementation of that resource, rather than the system.

Re: recording the implicit reference: tokens can easily be made to do this, with a little extension on what CfnReference does today. They have all the required information. However, we'd lose the property that bucket.bucketName === "hello", we'd be back to bucket.bucketName === "${Token[Bucket.Ref.123]}", with the difference that in the template that Token would resolve to a literal instead instead of an intrinsic.

Seems good enough to me, but YMMV?

[skinny85]

This is a duplicate of #928 . Same reasons posted there apply here as well.