Automating multi-arch container images builds (we used Google Cloud Build but GitHub Actions would also work)

This is the last post in the series on how we prepared our application to run on M1 (Apple Silicon).

In the previous part we were talking about building multiple CPU architecture container images.

This post will guide you through how to implement a pipeline for building multi-architecture container images using Google Cloud Platforms Cloud Build or GitHub Actions.

As you may know from the previous post, to build multi-arch container images we need to setup virtual environment and run docker buildx.

Let's configure such build pipelines for some popular CI/CD solutions.

Cloud Build

Cloud Build is a service that executes your builds on Google Cloud Platform's infrastructure.

To run multi-arch container images builds let's use the following pipeline configuration:

steps:  - name: gcr.io/cloud-builders/docker    args:      - run      - '--privileged'      - 'linuxkit/binfmt:v0.7'    id: initialize-qemu  - name: gcr.io/cloud-builders/docker    args:      - buildx      - create      - '--name'      - mybuilder    id: create-builder  - name: gcr.io/cloud-builders/docker    args:      - buildx      - use      - mybuilder    id: select-builder  - name: gcr.io/cloud-builders/docker    args:      - buildx      - inspect      - '--bootstrap'    id: show-target-build-platforms  - name: gcr.io/cloud-builders/docker    args:      - buildx      - build      - '--platform'      - $_DOCKER_BUILDX_PLATFORMS      - '-t'      - 'gcr.io/$PROJECT_ID/hello-world:latest'      - '--push'      - .    id: build-multi-architecture-container-imageoptions:  env:    - DOCKER_CLI_EXPERIMENTAL=enabledsubstitutions:  _DOCKER_BUILDX_PLATFORMS: 'linux/amd64,linux/arm64'

The above configuration creates the pipeline to set up the build environment (initialize-qemu, create-builder, select-builder, and show-target-build-platforms steps), to build a multi-arch container image and to push it to the Container Registry on Google Cloud Platform (build-multi-architecture-container-image step).

To push to another container registry (e.g. Docker Hub) update the build-multi-architecture-container-image step accordingly.

Please consult the Cloud Build documentation to get the information on how to trigger builds (manually or automatically).

GitHub Actions

If you prefer to use GitHub Actions instead of Cloud Build, it is also possible.

The pipeline configuration to build multi-arch container images is the following:

name: cion:  push:jobs:  buildx:    runs-on: ubuntu-latest    steps:      - name: checkout code        uses: actions/checkout@v2      - name: setup qemu        uses: docker/setup-qemu-action@v1      - name: setup buildx        id: buildx        uses: docker/setup-buildx-action@v1      - name: available platforms        run: echo ${{ steps.buildx.outputs.platforms }}      - name: login to docker hub        uses: docker/login-action@v1        with:          username: ${{ secrets.DOCKER_USERNAME }}          password: ${{ secrets.DOCKER_TOKEN }}      - name: build the image        run: |          docker buildx build \          --push \          --tag ${{ secrets.DOCKER_USERNAME }}/hello-world:latest \          --platform linux/amd64,linux/arm64 . 

To make it work you need to set up some secrets on GitHub:

• DOCKER_USERNAME your user name on Docker Hub
• DOCKER_TOKEN your Docker Hub access token

Conclusion

That was the last post in the series, and to sum up let's repeat the key points on how to prepare an application for M1 (Apple Silicon):

1. Use Go to easily build applications for different operating systems
2. Build multi-arch container images with docker buildx
3. Utilize Cloud Build or GitHub Action to automate builds