This is an OCurrent pipeline that builds Docker images for OCaml, for various combinations of Linux distribution, Windows version, OCaml version and architecture.

The resulting images can be run as e.g.

docker run --rm -it ocaml/opam:debian-11-ocaml-4.14

These images are very similar to the ones previously available as ocaml/opam2, and use the same scripts from ocurrent/ocaml-dockerfile. However, they are much smaller because each image only includes one OCaml compiler.

Each image includes two Dockerfiles showing how it was made:

• /Dockerfile.opam is the first stage, which just installs the opam binary.
• /Dockerfile.ocaml builds on the first stage by installing a particular opam switch.

The service is running at https://images.ci.ocaml.org/.

The rest of this README is about working on the build pipeline.

Testing locally

To see the pipeline, clone the repository and run docker-compose up:

git clone --recursive https://github.com/ocurrent/docker-base-images.git
docker-compose up

This runs with --confirm harmless, so that it will just show what it plans to do without trying to run any jobs yet. You should see:

   current_web [INFO] Starting web server: (TCP (Port 8080))

If you now browse to http://127.0.0.1:8080 you can see the build pipeline. Note: It might complain about --submission-service being missing at first, but should fix itself once the scheduler service has started. It should look something like this:

It starts by cloning opam-repository, then creates images by installing an opam binary and a copy of opam-repository for many Linux distributions and architectures.

These architecture-specific images get pushed to a staging repository on Docker Hub, and are then combined into a single multi-arch image.

Separately, the architecture-specific base images are also used to create more images - one for each supported OCaml compiler version. These images are also pushed to a staging repository and then combined into multi-arch images.

You can click on a box (e.g. the opam-repository clone step) and then on Start now to run that step manually, or you can set the confirmation threshold to >= Average on the main page. The docker-compose file includes a single builder running locally, using the linux-x86_64 pool and limited to one build at a time. You might want to update this, or add more builders. See the OCluster documentation for more information about that.

The pipeline is defined in pipeline.ml. This includes the Dockerfile definitions used to build the images.

Once running with your chosen configuration, you can use the web UI to raise (or remove) the confirmation threshold.