scream314 / docker-multiarch-builder

Simple framework for building multi-arch images

docker-multiarch-builder

Simple framework for building multi-arch images.

Preparing your build machine

Install the following packages using your package manager:

• docker (required, should be recent enough to support the manifest command, so at least 18.02.0-ce)
• qemu-user-static (recommended, but the script will download the binaries from GitHub for you if they are missing)

Run following commands on a host only once:

$ ./run-once.sh

This will check dependencies and register necessary binfmt_misc handlers.

Running ./run-once.sh multiple times should not cause any harm.

Initializing your project

When you want to create your Docker project, run this first:

$ mkdir /usr/src/docker-project-name
$ ./init-repo.sh /usr/src/docker-project-name

This will download static qemu binaries into your project qemu/ directory (if they are not installed already), prepare a stub of your Dockerfile.cross, and provide a local copy of your build.sh and build.config that you should use to build your images.

Runnig ./init-repo.sh multiple times on the same project should not cause any harm and it can be used to "install" a newer ./build.sh.

WARNING: Currently if the build.sh in the project differs form the current build.sh, the project's build.sh will be renamed and a new build.sh is installed.

Configuring build process

WARNING: The structure of build.config changed. "REPO" is deprecated, but still working.

Build configuration is in build.config in your project directory. It has number of parameters:

• IMAGE_NAME (required) - Image name that you would like to build. Probably your project name.
• TARGET_ARCHES (required) - List of target architectures you would like to build.
• REGISTRY (optional/required) - The address of the registry to use. Assuming docker.io if empty. You should already be logged in and have write access to this registry. You should at least specify either REGISTRY or REPOSITORY or both.
• REPOSITORY (optional/required) - Name of your repository ("sub-directory"). Assuming / if empty. You should at least specify either REGISTRY or REPOSITORY or both.
• IMAGE_VERSION (optional) - Leave empty for "latest"
• DOCKER_CLI_PATH (optional) - Path where docker CLI that supports manifest command is. You can leave it empty if you added it to path (or want to use the already installed docker command).
• BASE_IMAGE (optional) - The name of the base image to use. Defaults to alpine:edge if not specified.

Naturally, you should also edit your Dockerfile.cross and put meaningful build instructions. Just make sure __CROSS_COPY is placed before any RUN.

Keep __BASEIMAGE_ARCH__, __BASEIMAGE_NAME__, __CROSS_COPY and __QEMU_ARCH__ placeholder, as they are used to generate temporary Dockerfiles for each of the build architectures.

To actually build, tag images and push all of them + fat manifest to repository:

cd /usr/src/docker-project-name
./build.sh

(NOTE: You need to be logged in to the repository)