Build container image for arm64

[blockmar]

Today the release workflow seems to only build the container image for amd64.

It looks like ko support building multi-architecture images https://ko.build/features/multi-platform/

We use AWS arm graviton servers and would like to be able to run Allstar locally without having to rebuild the image for the arm64 platform.

[jeffmendoza]

Hello, yes we'd be happy to build and publish those images as well. If you'd like to submit a PR I'll review and merge, otherwise I'll find some time over the winter break to add this.

[blockmar]

Thank you for a quick response.

I'm familiar with the ko build command but checked documentation and tried manually triggering the updated release workflow in my fork. I could successfully pull and run arm images.

Created a PR: #615

[jeffmendoza]

Thanks for that PR! I merged and tried a release. Looks like the arm image built and published correctly, but then our cosign step failed as the ref files have multiple lines. We probably just need a bash for loop on that file.

https://github.com/ossf/allstar/actions/runs/12402656909/job/34624614005

[blockmar]

I've added my go of a fix. Feel free not to use it if you have a nicer solution.