docs.yml

name: Docs

# Build the Antora site on every PR, and publish to GitHub Pages on pushes to
# develop / main. Adapted from SKaiNET's docs workflow; this repo has no Gradle
# doc-generation step, so it goes straight to the Docker Antora build.

on:
  push:
    branches: [ main, develop ]
    paths:
      - 'docs/**'
      - '.github/workflows/docs.yml'
  pull_request:
    paths:
      - 'docs/**'
      - '.github/workflows/docs.yml'
  workflow_dispatch:

concurrency:
  group: docs-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read
  pages: write
  id-token: write

jobs:
  build-docs:
    runs-on: ubuntu-latest
    timeout-minutes: 30
    steps:
      - name: Checkout
        uses: actions/checkout@v7

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4

      # The Chromium layer makes the image ~400 MB. First build is a few minutes;
      # subsequent runs are sub-minute via the GHA cache.
      - name: Build Antora image
        uses: docker/build-push-action@v7
        with:
          context: docs/.docker
          tags: skainet-antora:local
          load: true
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Build Antora site
        # Run as the runner user (not root) so the generated site tree is owned
        # by the same user the upload step runs as.
        run: |
          docker run --rm \
            --user "$(id -u):$(id -g)" \
            -v "${{ github.workspace }}:/antora" \
            --workdir /antora/docs \
            skainet-antora:local \
            --stacktrace \
            antora-playbook.yml

      - name: Upload artifact
        uses: actions/upload-pages-artifact@v5
        with:
          path: docs/build/site

  deploy-docs:
    if: (github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/main') && github.event_name == 'push'
    needs: build-docs
    runs-on: ubuntu-latest
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    steps:
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v5