roles/git-submodules/tasks/main.yaml

- name: Prepare git submodules
  shell: |
    set -ex

    jq -r '.projects | .[] | .src_dir ' ~/zuul-env.json | while read PROJECT; do
      pushd "{{ ansible_user_dir }}/${PROJECT}"
      # 1) Adjust the origin's URL so that it points to its filesystem location.
      # This makes relative URLs in submodules work.
      git config --get remote.origin.url > /dev/null && git config remote.origin.url "{{ ansible_user_dir }}/${PROJECT}" || true
      # 2) Prepare an alias for each repository, appending the .git suffix.
      # E.g. Boost uses submodule URLs which end with a .git trailing suffix.
      # That happens to be handled by many git servers automagically.
      # Instead of rewriting the submodule URLs within each repo (which would either mark
      # the repo dirty, or change its hash), use a big hammer and provide these
      # "compatibility" repository names.
      # If both a `repo` and `repo.git` already exist, then we're screwed.
      ln -s $(basename "${PROJECT}") ../$(basename "${PROJECT}").git
      popd
    done

    # 3) Update submodules via calling out to git
    IFS=':' read -ra SUBMODULES_TO_EXPAND <<< "{{ git_submodule_dirs | default(zuul.project.src_dir) }}"
    for A_REPO in "${SUBMODULES_TO_EXPAND[@]}"; do
      pushd "${A_REPO}"
      git submodule update --init --recursive
      popd
    done

    # 4) Undo changes made in step 1
    jq -r '.projects | .[] | .src_dir ' ~/zuul-env.json | while read PROJECT; do
      pushd "{{ ansible_user_dir }}/${PROJECT}"
      git config --get remote.origin.url > /dev/null && git config remote.origin.url file:///dev/null || true
      popd
    done