03 Jan 2020 , tagged: Docker, buildx, ARM

Building Docker Containers for ARM with buildx

I’ve spent some time over the holidays building a Kubernetes cluster running on raspberry pis. One issue I ran into was that not all docker images I wanted to run were available for arm/linux. Luckily there’s a useful tool called buildx that extends Docker to build containers for different platforms and architectures using quemu and binfmt. ARM has a blog post that details the steps needed to build images.

The steps are:

docker run --rm --privileged docker/binfmt:820fdd95a9972a5308930a2bdfb8573dd4447ad3
docker buildx rm arm-builder
docker buildx create --name arm-builder
docker buildx inspect --bootstrap arm-builder

There appears to be a bug where the builder loses the other supported platforms after a reboot/restart but removing the builder and readding it seems to fix it.