Building Multi Architecture Golang Docker Images with GitLab CI/CD

The motivation is to provide Docker images for use with the AWS EC2 A1 Instances that deliver significant cost savings and are ideally suited for scale-out and Arm-based workloads that are supported by the extensive Arm ecosystem. A1 instances are the first EC2 instances powered by AWS Graviton Processors that feature 64-bit Arm Neoverse cores and custom silicon designed by AWS.

The build stage of the GitLab DinD (Docker-in-Docker) pipeline is based on Makefile and Docker Manifest feature to transparently provide multi-arch info to the Docker client. It uses docker manifest command which is experimental and needs to be enabled by editing the ~/.docker/config.json file and setting experimental to enabled for the user running the Docker client. The same parameter but with value true needs to be enabled for the Docker daemon too in the /etc/docker/daemon.json file.

At the end of the GitLab pipeline we end up with multiple images in our private Registry as shown below:

By providing Docker Manifest to the registry we make it possible to always reference our image as $DOCKER_REGISTRY/projects/go-proxy-multiarch:[f5b1c7f | latest] for example no matter the architecture we are running on and the docker client will pull down the correct image for us.

For more info see the README file in the provided GitHub repository.