chore(ci): build multiarch in github actions

[jeboehm]

Hi
I deploy Dockerize by using multistage Docker builds and copying the binary from your provided Docker image very often.
Yet there are no arm64 images available although ARM on Mac and ARM-Servers are more and more common.

This pull request adds a a workflow to build and push images to the ghcr.io repository for both architectures. Additionally, the images will be signed with the commit hash to provide a little extra layer of security (I think).

It was not possible for me to find out how you push images to the docker.io repository at the moment. I'd suggest to extend the workflow to do that: https://docs.docker.com/build/ci/github-actions/push-multi-registries/

[munir131]

@jeboehm I don't understand why we need docker images? Do you want to get binary from docker images when build your images? This is library so docker image might be not that much useful. For multi arch image you can use https://github.com/jwilder/dockerize/releases/tag/v0.9.9 like we are doing here - https://github.com/Improwised/docker-php-base/blob/master/Dockerfile#L6

[jeboehm]

Could you please elaborate on what your example has to do with multi arch?

The project already provides Docker images. They're incompatible with ARM. This PR solves that.

[munir131]

@jeboehm In my example, image that we are building it is multi-arch image. Might be in your case you are using dockerize image directly.

[jeboehm]

@jeboehm In my example, image that we are building it is multi-arch image. Might be in your case you are using dockerize image directly.

In line 6 you are downloading the amd64 variant.

[munir131]

@jeboehm Apologies, I pasted the wrong link. Here is correct link - https://github.com/Improwised/docker-php-base/blob/8.4-s6/Dockerfile#L15

[jeboehm]

Thank you.
I still think that my proposal is better.

You add a layer of complexity that is already solved in the underlying technology: Docker.

With multi-arch images you just do

COPY --from=jwilder/dockerize:0.9.4 /bin/dockerize /usr/local/bin/dockerize

and you're done.
Remember that we already have this image, it's just not complete.

[munir131]

Yes. That will be nice