Prepare image before running a script.

[MrCyjaneK]

So as we agreed:

It would be nice to have an option to build images, that will be used later (to avoid time/network consuming tasks such as downloading and installing software)

• We need an option to tag workers (image built on amd64 won't work on arm64) So until tagging the workers won't get work, implementing this feature will not make sense on some setups.
• There should be an option (not strictly related to this issue) to build something on multiple configurations - trigger one job (without using matrix, that should be done in webui) on multiple workers (so after a commit I can see if the package builds on debian:bullseye on aarch64, armhf and amd64
• Images should expire (keep them for up to x days)
• We need an webui (in my opinion it can be just a tab in repository settings), which should allow us to:
  • List all images and delete them manually
  • An Dockerfile(s) editor / or an option to use Dockerfile(s) from the repository. Each of them should have an option to tag them and use later, if tagged xyz you would use it like this: image: abstruse.registry/xyz:latest (the url will be dynamically edited)
  • An option for images to expire (my idea is to hash the dockerfile, and rebuild the image only when hash have changed or when x days have passed)