chore(docker): Build ARM64 images

[torqu3e]

Updates the Github action for building the docker images. Uses parallel runners to build image for each platform and then push the manifest after the build. Cross arch build here should be a relative non issue due to the infrequency of action run (~once every 2 months).

[CLAassistant]

All committers have signed the CLA.

[aliscott]

Thanks @torqu3e 🙏. It looks like this only updates the Dockerfile.ci (infracost:ci-*) images. I think we would want this to work on both the Dockerfile and the Dockerfile.ci images.

Any ideas how long this pipeline will take to run? One of the reasons we have a infrequent release cycle is because of the time for these pipelines to run so I'm hesitant about making it significantly slower.

[torqu3e]

@aliscott I don't see any mention of Dockerfile by itself in any other workflows. There's the create-test-image one which I've not seen run. Where are you referring to for the other files?

This will likely add some more time though hopefully not humongously so because of the parallel image builds. The majority of the time presently is in the go binary build which I can try to look into separate from this.

[aliscott]

@torqu3e the Dockerfile build is here:

infracost/.github/workflows/create-release.yml

Line 55 in acfffac

- name: Build and push Docker images

.

I'll see if I can run this in a test environment to see how much time it adds, but not sure how easy that will be.