Push Docker image for each PR

[ddeboer]

Each PR already builds Docker images. Why not also push them to Docker Hub, following the existing convention pr-{num}. Or, alternatively, push them to GHCR instead. This would smoothen processes such as #2635 (comment).

[hannahbast]

@ddeboer There already are images tagged qlever:pr-<num>, namely when the respective PR is merged into the master. These are useful because they make it very easy to use an older version of QLever.

When PRs are still in the works and under review, they might not be fully functional yet or even dysfunctional. I think it would be confusing to have Docker images for all of those as well. I agree that it is useful occasionally, but when that is the case, we can just push the respective images manually (like I did for qlever:REBUILD-INDEX-BETA)

[ddeboer]

@hannahbast If I'm not mistaken, you can already use older versions of QLever using the commit-... tags. In my opinion, it’s okay to have half-baked tags for the PRs. It shouldn't confuse people because they can just rely on either latest or commit-.... Pushing images manually has the downside that it may be forgotten and has to be repeated if any changes are pushed to the PR.

Of course, this is not my project, so feel free to make up your own mind about this and close this issue if you want to keep things as they are.

[giacomociti]

what a timely request 😃 , I would appreciate having a docker image for #2642 available in some public registry