There should be a much less complex workflow and set of actions for using multiple runners to build multi-arch images #393

At the moment, it is much too complex to use multiple runners when building multi-arch images.

My workflow is pretty clean when I just use buildx to build all the platforms, but it is also way too slow due to the QEMU emulation. Using multiple runners of the correct platform/arch is MUCH faster, but the workflow is a mess and, the resulting manifest is not ideal.

It would be great if there was an action that was designed to intelligently and cleanly merge multiple manifests. Most of my images have many tags on them from the docker/metadata-action action, and merging all of those is painful.

It seems like this workflow is likely to become more and more common with the introduction of arm64 runners. In the meantime, if anyone has a workflow they are really happy with sharing it here would be great.

At the moment, my flow uses: these actions:

• actions/checkout@v4
• actions-tools/yaml-outputs@v2.1
• docker/metadata-action@v5
• docker/setup-buildx-action@v3
• docker/login-action@v3
• docker/build-push-action@v5
• Noelware/docker-manifest-action@master

There is a lot of duplication for each architecture in the current flow, and the assembly of the final manifest only handles the latest tag at the moment, even though there are a lot more defined in the metadata action for each platform.