gh_pages.yml

# Build and deploy documentation to GitHub Pages
name: GitHub Pages

on: 
  push:
    branches:
      - main
  pull_request:
  workflow_dispatch:

env:
  DEFAULT_BRANCH: "release"

jobs:
  build-and-deploy:
    name: Build and deploy to gh-pages
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          lfs: true

      - name: Debugging information
        run: |
          echo "github.ref:" ${{github.ref}}
          echo "github.event_name:" ${{github.event_name}}
          echo "github.head_ref:" ${{github.head_ref}}
          echo "github.base_ref:" ${{github.base_ref}}
          set -x
          git rev-parse --abbrev-ref HEAD
          git branch
          git branch -a
          git remote -v
          python -V
          pip list --not-required
          pip list

      # Clone and set up the old gh-pages branch
      - name: Clone old gh-pages
        if: ${{ github.event_name == 'push' }}
        run: |
          set -x
          git fetch
          ( git branch gh-pages remotes/origin/gh-pages && git clone . --branch=gh-pages _gh-pages/ ) || mkdir _gh-pages
          rm -rf _gh-pages/.git/
          mkdir -p _gh-pages/branch/

      # If a push and default branch, copy build to _gh-pages/ as the "main"
      # deployment.
      - name: Build and copy documentation (default branch)
        if: |
          contains(github.event_name, 'push') &&
          contains(github.ref, env.DEFAULT_BRANCH)
        run: |
          set -x
          mkdir -p _build/html/versions

          # create two copies of the documentation
          # 1. the frozen version, represented as vX.X in the version switcher
          docker build -t music_box -f docker/Dockerfile.docs .
          id=$(docker create music_box)
          docker cp $id:/build/docs/build/html tmpdocs
          docker rm -v $id
          version=$(sed -nr "s/^release = f'v(.+)\{suffix\}'.*$/\1/p" docs/source/conf.py)
          mv tmpdocs _build/html/versions/${version}

          # 2. stable, represented as vX.X (stable) in the version switcher
          # edit conf.py to produce a version string that looks like vX.X (stable)
          docker build -t music_box -f docker/Dockerfile.docs --build-arg SUFFIX=" (stable)" .
          id=$(docker create music_box)
          docker cp $id:/build/docs/build/html tmpdocs
          docker rm -v $id
          mv tmpdocs _build/html/versions/stable
          # Delete everything under _gh-pages/ that is from the
          # primary branch deployment.  Excludes the other branches
          # _gh-pages/branch-* paths, and not including
          # _gh-pages itself.
          find _gh-pages/ -mindepth 1 ! -path '_gh-pages/branch*' ! -path '_gh-pages/versions*' -delete
          rsync -a _build/html/versions/stable/* _gh-pages/
          mkdir -p _gh-pages/versions
          rsync -a _build/html/versions/* _gh-pages/versions
          # mv docs/switcher.json _gh-pages

      # If a push and not on default branch, then copy the build to
      # _gh-pages/branch/$brname (transforming '/' into '--')
      - name: Build and copy documentation (branch)
        if: |
          contains(github.event_name, 'push') &&
          !contains(github.ref, env.DEFAULT_BRANCH)
        run: |
          set -x
          docker build -t music_box -f docker/Dockerfile.docs .
          id=$(docker create music_box)
          docker cp $id:/music-box/docs/build/html tmpdocs
          docker rm -v $id
          brname="${{github.ref}}"
          brname="${brname##refs/heads/}"
          brdir=${brname//\//--}   # replace '/' with '--'
          rm -rf   _gh-pages/branch/${brdir}
          rsync -a tmpdocs/ _gh-pages/branch/${brdir}

      # Go through each branch in _gh-pages/branch/, if it's not a
      # ref, then delete it.
      - name: Delete old feature branches
        if: ${{ github.event_name == 'push' }}
        run: |
          set -x
          for brdir in `ls _gh-pages/branch/` ; do
              brname=${brdir//--/\/}   # replace '--' with '/'
              if ! git show-ref remotes/origin/$brname ; then
                  echo "Removing $brdir"
                  rm -r _gh-pages/branch/$brdir/
              fi
          done

      # Add the .nojekyll file
      - name: nojekyll
        if: ${{ github.event_name == 'push' }}
        run: |
          touch _gh-pages/.nojekyll

      # Deploy
      # https://github.com/peaceiris/actions-gh-pages
      - name: Deploy
        uses: peaceiris/actions-gh-pages@v3
        if: ${{ github.event_name == 'push' }}
        with:
          publish_branch: gh-pages
          github_token: ${{ secrets.GITHUB_TOKEN }}
          publish_dir: _gh-pages/
          force_orphan: true