docker support for Containerfile name

[andrewazores]

Fixes #6067

[andrewazores]

Not really a Rubyist here and not sure how to update the VCR fixtures properly.

[jeffwidman]

👋 Thanks for putting this up. I keep meaning to review it but just haven't had time yet. One of us will try to get to it in the next few days.

[dhirschfeld]

Any interest in allowing a full filepath since neither docker nor buildah require any particular naming convention for the file - you can call it whatever you want and point docker/buildah to it with --file

https://docs.docker.com/engine/reference/commandline/build/#specify-a-dockerfile--f

[dhirschfeld]

My interest in this feature is that I often have multiple dockerfiles alongside each other in the same repository.

I use a meaningful-name.docker convention and name my images after the filename they were created from. It would be great if I could somehow tell dependabot to look for meaningful-name.docker instead of hardcoding Dockerfile.

e.g. maybe something like

updates:
  - package-ecosystem: "docker"
    directory: "/build/docker"
    manifest-name: "meaningful-name.docker"

This could be made backward compatible by having a package-ecosystem default value for manifest-name which is just the existing hardcoded value.

[ssbarnea]

That also made me curious, is there any YAML file on which dependabot github app can update container versions?

I see that the source code mentions kubernetes YAML files but there is nothing inside the documentation for that.

[sid-maddy]

Could this PR be picked up for review? AFAICT, it only needs a rebase onto main.

Also, from the comments here and in the linked issue, there seems to be interest in allowing users to provide the manifest names via the Dependabot config file.
AFAICT, this would need changes in docker's file fetcher & updater (my WIP attempt) as well as the logic (not sure where) that parses package manager specific options from the config file.

Could that be included in this PR as well?

[andrewazores]

Done by #11141 instead