Specify custom config for buildx

[GMartinez-Sisti]

Hi, I've been trying to use a custom config with the following syntax:

      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v1
        with:
          version: latest
          buildkitd-flags: --config /etc/buildkit/buildkitd.toml

$ cat /etc/buildkit/buildkitd.toml
[registry."docker.io"]
    mirrors = ["nexus.internal.domain"]

The docker config also uses the same registry and I can see that the buildx image is pulled from the configured mirror, but images used by buildx are not respecting the configuration and going straight to Docker Hub. Initially I tried to use the variable DOCKER_CONFIG but looks like it's only used to specify the plugin directory here.

Using the configuration locally works with:

docker buildx create --config /etc/buildkit/buildkitd.toml --use

I'd like to avoid specifying the configuration as arguments to prevent having to change all the workflows every time something changes. Is this feature supported by this action?

(Initial report -> docker/buildx#136)

Thanks

[crazy-max]

@GMartinez-Sisti

Is this feature supported by this action?

Sure LGTM

[GMartinez-Sisti]

@crazy-max I can send a PR with a new input named config, just not sure how to test it.

[crazy-max]

@GMartinez-Sisti

just not sure how to test it.

I think we could use a docker hub mirror (like mirror.gcr.io one) to test the behavior for your case. Will let you know.

[crazy-max]

@GMartinez-Sisti Ok feel free to open a PR. We will discuss how to include a test on it.