sync-upstream.yml

name: 🔄 Sync with upstream

on:
  workflow_call:
    outputs:
      missing_tags:
        description: The upstream tags that are missing locally
        value: ${{ jobs.sync_upstream.outputs.missing_tags }}
      snapd_tags:
        description: The new tags that we need to create
        value: ${{ jobs.sync_upstream.outputs.snapd_tags }}

jobs:
  sync_upstream:
    runs-on: ubuntu-latest
    steps:
    - name: Install dependencies
      run: |
        sudo apt-get update
        sudo apt-get install -yyq jq
    - uses: actions/checkout@v3
    - name: Configure GIT
      run: |
        git config user.email 'actions@github.com'
        git config user.name 'GitHub Actions'
        git remote add upstream https://github.com/microsoft/WSL2-Linux-Kernel.git
    - name: Sync from upstream
      run: |
        git fetch --tags origin
        git fetch --tags --prune --progress --no-recurse-submodules upstream +refs/heads/master*:refs/remotes/upstream/master*
    - name: Parse upstream tags
      id: parse_tags
      run: |
        set -x

        REMOTE_TAGS="$(git show-ref --tags | awk '{print $2}' | cut -d/ -f3 | grep '^linux-msft-wsl-' || true)"
        ORIGIN_TAGS="$(git ls-remote --tags origin | grep -v '\^{}' | cut -f2 | cut -d/ -f3 | grep '^linux-msft-wsl-' || true)"

        MISSING_TAGS="$(echo "$REMOTE_TAGS" | grep -v -F "$ORIGIN_TAGS" || true)"

        FILTERED_UPSTREAM_TAGS=()
        FILTERED_SNAPD_TAGS=()

        for UPSTREAM_TAG in $MISSING_TAGS; do
          # check that we have a non-empty string
          [ -n "$UPSTREAM_TAG" ] || continue

          # check that the tag name matches the format we're expecting
          echo "$UPSTREAM_TAG" | grep -Eq '^linux-msft-wsl-([0-9]+\.[0-9]+).*$' || continue

          # check that we haven't already built this tag
          SNAPD_TAG="${UPSTREAM_TAG/linux-msft-wsl-/linux-msft-snapd-}"
          [ -z "$(git tag -l "$SNAPD_TAG")" ] || continue

          FILTERED_UPSTREAM_TAGS+=($UPSTREAM_TAG)
          FILTERED_SNAPD_TAGS+=($SNAPD_TAG)
        done

        echo '::echo::on'
        if [ "${#FILTERED_UPSTREAM_TAGS[@]}" -gt 0 ]; then
          echo "::set-output name=missing_tags::$(jq --compact-output --null-input '$ARGS.positional' --args -- "${FILTERED_UPSTREAM_TAGS[@]}")"
          echo "::set-output name=snapd_tags::$(jq --compact-output --null-input '$ARGS.positional' --args -- "${FILTERED_SNAPD_TAGS[@]}")"
        else
          echo "::set-output name=missing_tags::"
          echo "::set-output name=snapd_tags::"
        fi
    - name: Rebase and push master; push tags
      run: |
        git rebase upstream/master
        git push --force        origin master
        git push --force --tags origin
    outputs:
      missing_tags: ${{ steps.parse_tags.outputs.missing_tags }}
      snapd_tags: ${{ steps.parse_tags.outputs.snapd_tags }}