build_docker.yml

name: Build with ocp Docker container

# The goal of this workflow is to test the installation of the project with opam
# on a specific light docker container instead of using default GH-actions one.
on:
  push:
    branches:
      - fix-ci
      - next
      - main

jobs:
  install_docker:
    name: opam install on a specific docker container

    runs-on: ubuntu-latest

    # Retrieve and use a light docker container on which ocaml 4.10 is installed
    # as a system compiler. This container also contains opam 2.1.
    container:
      image: ocamlpro/ocaml:4.10
      options: --user root

    steps:

      # Checkout the code of the current branch
      - name: Checkout code
        uses: actions/checkout@v3

      # Switch to ocaml user
      - run: su ocaml

      # This line is needed to acces and use opam. We are unable to set the user
      # to `ocaml` with the container parameters
      - run: sudo chmod a+wx .

      # This line is needed to allow the working directory to be used even
      # the ocaml user do not have rights on it.
      - run: CURRENTDIR=$(basename $(pwd)); git config --global --add safe.directory /__w/$CURRENTDIR/$CURRENTDIR

      - name: Update opam repository
        run: opam update

      # Create a switch with the system compiler (no compilation needed).
      # And then, install external (no need for depext with opam 2.1) and libs deps.
      - run: opam switch create . ocaml-system --deps-only --ignore-constraints-on alt-ergo-lib,alt-ergo-parsers

      # Install the project packages
      - run: opam install .