Generating tags for multiple bake targets

[Pesa]

Description

Let's say I have the following docker-bake.hcl:

group "default" {
  targets = ["foo", "bar"]
}

target "foo" {
  dockerfile = "Dockerfile.foo"
  tags = ["my/foo:latest"]
}

target "bar" {
  dockerfile = "Dockerfile.bar"
  tags = ["my/bar:latest"]
}

The tags listed above function a bit like defaults, i.e., they're used when I run bake locally for testing. On GitHub Actions, however, I'd like to use docker/metadata-action to generate a list of tags based on various criteria (semver, date, etc...). These generated tags should replace the :latest tag from docker-bake.hcl, but I still want to keep the base name of the two images (my/foo and my/bar).

This would be trivial to accomplish with a single target (using the images input), but I didn't find a way to do it for multiple targets, where each target has a distinct image name.

Apologies if I missed something obvious (seems odd that this use case isn't already supported, since the whole point of bake is orchestrating the build of multiple targets).