Add commit SHA to branch / edge images

[devinrsmith]

This is similar to #46, but specifically focused on adding commit SHA details to branch / edge images. We should be able to capture environment / checkout details for these branch / edge workflows and pass through those details into the image.

[devinrsmith]

This feature could also be considered more widely solved via deephaven/deephaven-core#3705; that said, there is still room for us to add deephaven-server-docker build sourced information, even if the above issue is completed.

[stanbrub]

Are you thinking of something like the following idea for the interim?

docker build --build-arg GIT_COMMIT=$(git rev-parse HEAD) -t my_image:my_tag

Or ${{ GITHUB_SHA }}?

That would mean it's captured in the image, but it would not be reachable in a native build.

[stanbrub]

Here's an example to set the deephaven-core commit hash to an environment variable in the docker image. https://github.com/deephaven/deephaven-server-docker/compare/main...stanbrub:deephaven-server-docker:commit-hash-in-image?expand=1. Not complete but shows something working.

[devinrsmith]

Yes, something like that. I think we want to ultimately propagate it into the LABEL field.

I would have hoped that the checkout action had an official output, but it looks like it doesn't (although, it seems like a pretty popular feature request, actions/checkout#209).

[devinrsmith]

org.opencontainers.image.revision would be the best label; https://github.com/opencontainers/image-spec/blob/main/annotations.md