Multi arch matrix pipeline

[alcohol]

• setup multi arch pipeline for
  • current
  • lts
  • previous versions (or just remove these?)
  • v1 (or just remove?)

[alcohol]

@tianon @crazy-max I hope I am not imposing here; I am trying to wrap my head around setting up multi-arch builds for our non-official images. I have looked at various documentation sources and your repository which was also referenced somewhere as an example. But I am not sure I am getting it.. any pointers on where I might be overlooking something would be greatly appreciated. Right now I managed to get the digests pushed, and the manifest merged, but labels (or annotations for multi-arch ?) seem to be missing still. I am also seeing an unknown/unknown arch when I look at the tagged versions over at https://github.com/composer/docker/pkgs/container/docker/ which I cannot figure out where it is coming from.

There is also the minor added complexity of having to have builds based on tags/source from another repository (composer/composer) using:

• multiple directories / workflows;
• multiple container repositories to push to;
• two different build outputs (based on target).

Sources I have referenced:

• https://docs.docker.com/build/building/multi-platform/
• https://docs.docker.com/build/ci/github-actions/multi-platform/
• https://docs.docker.com/build/ci/github-actions/push-multi-registries/
• https://github.com/crazy-max/docker-linguist/blob/master/.github/workflows/build.yml

The following also does not look right..

$ docker run --rm mplatform/mquery composer/composer:lts
Unable to find image 'mplatform/mquery:latest' locally
latest: Pulling from mplatform/mquery
f7727aa0d57a: Pull complete
2db63f065e4b: Pull complete
Digest: sha256:d0989420b6f0d2b929fd9355f15c767f62d0e9a72cdf999d1eb16e6073782c71
Status: Downloaded newer image for mplatform/mquery:latest
Image: composer/composer:lts (digest: sha256:e951c2fee044548fa9a846f1e1a2de4adb53155cfba21290dae5cedb462ba071)
 * Manifest List: Yes (Image type: application/vnd.oci.image.index.v1+json)
 * Supported platforms:
   - linux/s390x
   - unknown/unknown
   - linux/arm/v6
   - unknown/unknown
   - linux/riscv64
   - unknown/unknown
   - linux/386
   - unknown/unknown
   - linux/amd64
   - unknown/unknown
   - linux/ppc64le
   - unknown/unknown
   - linux/arm/v7
   - unknown/unknown
   - linux/arm/v8
   - unknown/unknown

[tianon]

Perhaps https://github.com/moby/buildkit/blob/ff1674a396491e55667a2a840352932993a0043a/docs/attestations/attestation-storage.md is a helpful link for you 👀

[alcohol]

Honestly? Not really..

I do not really have enough spare time to dive very deep into this subject matter. I find it rather complex and not easy to comprehend. Things seems to work in the current shape of this PR though according to an end user who requested this feature, so I guess sufficient copy&paste and trial&error will make do for now 😅

[tianon]

Hah, fair! 💕