Auto populate the container version based on a "primary rpm" version

[cverna]

After opening [0] in koji-containerbuild it seems that atomic-reactor is a better place to implement this feature.
After briefly looking at the pre_bump_release plugin, I think the best way would be to create a similar plugin.

My inital thoughts are :

• Dockerfile to have a new label that stores the primary rpm used to populate the version of the container for example "rpm.version". (we might be able to reuse the component label but having a new label brings flexibility)

• "rpm.version" to be added to the LABEL_TYPE_VERSION so a Dockerfile with only "rpm.version" will be valid. If this label is not used then we still need to provide the Version label.

• Add a new plugin in atomic-reactor (pre-build)

  • plugin to read the "rpm.version" label content
  • plugin to query koji with getLatestBuild ---> This API requires a koji tag ( need to investigate how we can find out which tag to use)
  • plugin to use the result of koji getLatestBuild to replace the value of "rpm.version"

[0] - containerbuildsystem/koji-containerbuild#95

[lcarva]

plugin to query koji with getLatestBuild ---> This API requires a koji tag ( need to investigate how we can find out which tag to use)

This should be from either the koji build or destination tag of the given koji target.

[TomasTomecek]

Continuing discussion over here.

With post plugin, you would be 100% sure on the version. It's possible that querying koji could result into getting a different package than koji predicted? Also what about images which don't utilize koji for getting packages? When they get packages from dedicated repositories.

The implementation as a post build plugin could look like this:

1. version=$(docker run $image rpm -q --qf "%{version}" $package)
2. docker create --name working-container $image
3. docker commit -c "LABEL version=$version" working-container $image

[lcarva]

@TomasTomecek, the Dockerfile at /root/build-info would also need updating. The internal state of atomic-reactor must also be updated for tag_from_config plugin, for example. There could be other oddities too, which makes me shy away from this approach.

I wanna say that the safest way would be to do as a prebuild plugin, then verify it was correctly set, say in all_rpm_packages. But it would be great if we didn't tie this to koji at all.

I think postbuild would make the feature more versatile as it wouldn't require koji. I'm just concerned that implementation might not be as straight forward. Maybe it's worth giving that a try and see how it lands?

[lcarva]

Oh! It has to be done as a prebuild plugin if you want to leverage bump_release.

[TomasTomecek]

Maybe it's worth giving that a try and see how it lands?

+1

[cverna]

I see how the postbuild gives more flexibility and assurance that we have the correct version. It seems indeed a better solution that the prebuild.

I ll look at some postbuild plugin and try to see what I can do :)

[twaugh]

How would this work for container-first container images, where there may not be any RPMs at all?

[lcarva]

Closing due to lack of interest and activity. If you're still interested feel free to reopen it.