"cdk diff" should take assets into account

[eladb]

When running cdk diff, the toolkit should take assets into account. At the moment, if only assets change, "cdk diff" will show no differences, but "cdk deploy" will update the stack since the asset's md5 changes.

[brad-jones]

For a quick and dirty hack I just inject a hash of the asset into the stack somewhere, in the case of a lambda just set an environment variable. Then when running cdk diff it's obvious what will update.

new lambda.Function(this, 'SomeLambda', {
	code: lambda.Code.asset('/path/to/zip'),
	environment: {
		HASH: HashFuncOfYourChoice('/path/to/zip'),
	},
	etc...
});

[eladb]

Copy @sam-goodwin

[barroij]

Having the same issue, but as I'm not referencing a zip file but a directory, I cannot use @brad-jones workaround.

The zip md5 could be made available so that I can put its value an an output value (supposing that different output values buiolt with new Cdk.CfnOutput sould cause the stack to be deployed)

[jeffsee55]

Wonder if this could be achieved by using a checksum? That would have the benefit of #395 (comment) 's comment without having to zip beforehand.

Since the lambda.Code.fromAsset(..., would know the directory it may even be possible to perform automatically and store in metadata?

[eladb]

will be fixed by #2821