Using GitHub Actions to publish a static site to GitHub Pages

Automatically build a Middleman-generated site and push it to the gh-pages branch on every push to the master branch

I recently got access to the new GitHub Actions functionality and decided to experiment with using it to automatically build and deploy this site.

For the last three years I've been using Travis CI to automatically build this Middleman-generated site and publish it to a Linode VPS using rsync, although it has to be said I haven't published much in that time!

Rather than trying to replicate this behaviour exactly using GitHub Actions, I decided to try publishing to GitHub Pages; something I've been meaning to do for a while. This will mean I'm a bit closer to being able to get rid of my Linode VPS altogether.

I tried quite a few actions which claimed to do what I wanted, but ran into a few problems. The main problem turned out to be that while the GitHub token which is supplied to an action by default does allow pushing to the gh-pages branch, it doesn't allow triggering of a GitHub Pages build; instead you need to generate a Personal Access Token.

In the end I settled on this GitHub Pages Deploy action with a workflow configured as follows:

name: Continuous Deployment to GitHub Pages
      - master
    name: Build
    runs-on: ubuntu-latest
      - name: Checkout repo
        uses: actions/checkout@master
      - name: Setup Ruby
        uses: actions/setup-ruby@v1
          ruby-version: '2.6.3'
      - name: Install bundler
        run: gem install bundler:2.0.2
      - name: Install bundled gems
        run: bundle install
      - name: Build site
        run: bundle exec middleman build
      - name: Publish site
        uses: maxheld83/ghpages@v0.2.1
          GH_PAT: ${{ secrets.GH_PAT }}
          BUILD_DIR: ./build

I'm pretty happy with this solution so far, although I don't really understand why this action (and all the others I looked at) force pushes to the gh-pages branch rather than just pushing. I think it would be nice to have a historic record of the generated HTML in the git repo.