permaref.yaml

# Automatically creates a tag for each commit to `main` so when we rebase
# changes on top of the upstream, we retain permanent references to each
# previous commit so they are not orphaned and eventually deleted.
name: Create permanent reference

on:
  push:
    branches:
      - "main"

jobs:
  create-permaref:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Get the permanent ref number
        id: get_version
        run: |
          # Enable pipefail so git command failures do not result in null versions downstream
          set -x

          echo "LAST_PERMA_NUMBER=$(\
            git ls-remote --tags --refs --sort="v:refname" \
            https://github.com/zanieb/pubgrub.git | grep "tags/perma-" | tail -n1 | sed 's/.*\/perma-//' \
          )" >> $GITHUB_OUTPUT

      - name: Configure Git
        run: |
          git config user.name "$GITHUB_ACTOR"
          git config user.email "$GITHUB_ACTOR@users.noreply.github.com"

      - name: Create and push the new tag
        run: |
          TAG="perma-$((LAST_PERMA_NUMBER + 1))"
          git tag -a "$TAG" -m 'Automatically created on push to `main`'
          git push origin "$TAG"
        env:
          LAST_PERMA_NUMBER: ${{ steps.get_version.outputs.LAST_PERMA_NUMBER }}