Add support to build arm64 image

[kkimurak]

This PR allow us to build arm64 image in addition to currently supported amd64.

Originally I have posted a patch to #2603 . I would love to hear your thoughts (and hopefully reports on how it works) from the community here - including whether or not we should support it.

Also please note that this PR does not modify CI configuration - This is to ensure that this change does not break existing amd64 image builds and continues to work.

You can test this PR after applying the patch and run docker buildx build --platform linux/arm64 .

[kkimurak]

Made sure to pass shellcheck.

[kkimurak]

Corrected download message (uninitialized variable in use).

[kkimurak]

rebased onto 15.10.3

[kkimurak]

rebased onto 15.11.3

[kkimurak]

rebased onto 16.0.3.

If there is no plan to merge this work, it would be helpful if you could close it and state that there are no plans to prepare an image for the ARM64 platform.

[sachilles]

@kkimurak Apologies for my poor availability.

In principle I don't see any problems by supporting ARM64 if there are contributors that support this work an help to publish the corresponding images regularly. So far I didn't provide images for multiple architectures und thus, I'll need help on this.

[Jack12816]

I would love to see this merged and made available. <3 Thanks for the contribution @kkimurak!

Maybe this could help here to enable a multi-arch build via CircleCI.

I guess --platform=linux/amd64,linux/arm64 must be added to the docker build commands:

• https://github.com/sameersbn/docker-gitlab/blob/master/.circleci/config.yml#L79
• https://github.com/sameersbn/docker-gitlab/blob/master/.circleci/config.yml#L105

and the docker push works transparently.

@sachilles It would be great if you could merge this PR with the CI addition and see if CI is working properly. If not revert it - then we could iterate on this. :)

[kkimurak]

rebased onto 16.2.1.

[gjrtimmer]

I would really love this, waiting for my RK1 modules from turing pi. With this I can run my GitLab on my Turing PI.

[kkimurak]

Sorry for delay but

• I'm not going to maintain CI settings (as I stated at first)
• I've lost motivation because the only ARM64 device I owned broke.
• There is a concurrent work support arm architecture #2803. This can be confusing, and I think discussions with the same content should be grouped together (i.e. one should be closed).

I hope someone who need this will take over (or #2803 - not exactly same code but works) .

I apologize again for my selfish actions.