Docker, M1 Macs and EKS issue: exec format error

Most of the time, knowing what an error means can get you to the solution right away but when the error message is not descriptive enough, finding a solution can take a lot of time. While I didn’t spend days with this issue thanks to this article, I do want to share my current workaround since it doesn’t involve buildx but instead, using GitHub actions and deploying to EKS.

I am exploring my development environment in a new 14-inch MacBook Pro with Apple Silicon (M1 Max) and part of my workflow required to test a docker image to later deploy it in an EKS cluster.

Docker has a page about Docker Desktop for Apple Silicon here that you should read.

My workflow back on Intel was:

1. Pull the code from GitHub
2. Use or create the Dockerfile
3. Perform a Docker build
4. Run the image locally, test everything works
5. Push the image to ECR
6. Deploy the image un EKS with a Kubernetes Deployment and an Ingress object.

In my workflow, the Kubernetes pod was not starting.

$ kubectl logs my-pod-name-6cdbb74df6-jjdwr -n <NAMESPACE>
standard_init_linux.go:219: exec user process caused: exec format error

After this, I would typically create a GitHub Action and just get out of the manual steps, but with this new laptop my new process looks like this:

1. Pull the code from GitHub
2. Use or create the Dockerfile
3. Perform a Docker build
4. Run the image locally, test everything works
5. Create the Github Action, it builds the Docker image, pushes it to ECR and does the Kubernetes deployment.

The good: I think in the long term this makes my work more focused on getting things to work directly in the cluster.

The bad: Testing the image locally doesn’t really tell me if it’s going to work on the cluster, because there are in different architectures.

The article I mentioned in the beggining does have the laternative of using buildx which I’m pretty sure it can work but there is some outdated intructions so I shall come back to try to build x86_64 images in the M1.