The hooks in this directory are used to create multi-arch images using Docker Hub automated builds.

Docker Hub hooks provide these predefined environment variables:

• SOURCE_BRANCH: the name of the branch or the tag that is currently being tested.
• SOURCE_COMMIT: the SHA1 hash of the commit being tested.
• COMMIT_MSG: the message from the commit being tested and built.
• DOCKER_REPO: the name of the Docker repository being built.
• DOCKERFILE_PATH: the dockerfile currently being built.
• DOCKER_TAG: the Docker repository tag being built.
• IMAGE_NAME: the name and tag of the Docker repository being built. (This variable is a combination of DOCKER_REPO:DOCKER_TAG.)

The current multi-arch image build relies on the original vaultwarden Dockerfiles, which use cross-compilation for architectures other than amd64, and don't yet support all arch/distro combinations. However, cross-compilation is much faster than QEMU-based builds (e.g., using docker buildx). This situation may need to be revisited at some point.

References

• https://docs.docker.com/docker-hub/builds/advanced/
• https://docs.docker.com/engine/reference/commandline/manifest/
• https://www.docker.com/blog/multi-arch-build-and-images-the-simple-way/
• https://success.docker.com/article/how-do-i-authenticate-with-the-v2-api