build-docs.yml

name: Deploy Docs
on:
  push:
    branches:
      - master
      - "release-*" # older verions of the docs
      - docs-prod # prod
    paths:
      - docs/**
  pull_request:
    paths:
      - docs/**
concurrency:
  # Cancel in-progress runs on same branch
  group: ${{ github.ref }}
  cancel-in-progress: true
jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      # Deploy to Vercel Previews on pull request, push to master branch, or push to release-* branch
      - name: Get branch preview subdomain
        env:
          HEAD_REF: ${{ github.head_ref }}
          REF_NAME: ${{ github.ref_name }}
        if: |
          github.event_name == 'pull_request' || 
          (github.event_name == 'push' && (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/release-')))
        run: |
          BRANCH_PREVIEW_SUBDOMAIN=$(echo "${HEAD_REF:-$REF_NAME}" | sed -e 's/[^a-zA-Z0-9-]/-/g; s/^-*//; s/-*$//')
          echo "$BRANCH_PREVIEW_SUBDOMAIN"
          echo "BRANCH_PREVIEW_SUBDOMAIN=$BRANCH_PREVIEW_SUBDOMAIN" >> "${GITHUB_ENV}"

      - name: Checkout master/release branch
        if: github.event_name == 'push' && (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/release-'))
        uses: actions/checkout@v4

      - name: Get PR fetch depth
        if: ${{ github.event.pull_request }}
        run: echo "PR_FETCH_DEPTH=$(( ${{ github.event.pull_request.commits }} + 1 ))" >> "${GITHUB_ENV}"

      - name: Checkout PR branch
        uses: actions/checkout@v4
        if: ${{ github.event.pull_request }}
        with:
          fetch-depth: ${{ env.PR_FETCH_DEPTH }}

      - name: Get changed docs files for PR comment
        if: ${{ github.event.pull_request }}
        run: |
          echo "Head ref is $GITHUB_HEAD_SHA"
          git fetch origin $GITHUB_HEAD_SHA
          # Compare the commit the branch is based on to its head to list changed files
          CHANGED_MDX_FILES=$(git diff --name-only HEAD~${{ github.event.pull_request.commits }} "$GITHUB_HEAD_SHA" -- '*.mdx')
          CHANGES_ENTRY=$(echo "$CHANGED_MDX_FILES" | sed 's/\.mdx$//' | sed 's/^docs\/content/- {{deploymentUrl}}/')
          CHANGES_ENTRY=$(echo -e "Preview available at {{deploymentUrl}}\n\nDirect link to changed pages:\n$CHANGES_ENTRY")
          echo "$CHANGES_ENTRY"
          # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#multiline-strings
          EOF=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
          echo "CHANGES_ENTRY<<$EOF" >> $GITHUB_ENV
          echo "$CHANGES_ENTRY" >> $GITHUB_ENV
          echo "$EOF" >> $GITHUB_ENV
        env:
          GITHUB_HEAD_SHA: ${{ github.event.pull_request.head.sha }}

      - name: Publish Preview to Vercel
        uses: amondnet/vercel-action@v25
        if: |
          github.event_name == 'pull_request' || 
          (github.event_name == 'push' && (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/release-')))
        with:
          github-comment: ${{ github.event.pull_request && env.CHANGES_ENTRY || true }}
          vercel-token: ${{ secrets.VERCEL_TOKEN }}
          vercel-org-id: ${{ secrets.VERCEL_ORG_ID }}
          vercel-project-id: ${{ secrets.VERCEL_PROJECT_ID }}
          github-token: ${{ secrets.GITHUB_TOKEN }}
          scope: ${{ secrets.VERCEL_ORG_ID }}
          alias-domains: ${{ env.BRANCH_PREVIEW_SUBDOMAIN }}.dagster.dagster-docs.io

      # Deploy to Vercel Production on push to docs-prod branch
      - name: Checkout docs-prod branch
        if: github.event_name == 'push' && github.ref == 'refs/heads/docs-prod'
        uses: actions/checkout@v4

      - name: Publish to Vercel Production
        uses: amondnet/vercel-action@v25
        if: github.event_name == 'push' && github.ref == 'refs/heads/docs-prod'
        with:
          vercel-token: ${{ secrets.VERCEL_TOKEN }}
          vercel-org-id: ${{ secrets.VERCEL_ORG_ID }}
          vercel-project-id: ${{ secrets.VERCEL_PROJECT_ID }}
          vercel-args: "--prod"
          github-token: ${{ secrets.GITHUB_TOKEN }}
          scope: ${{ secrets.VERCEL_ORG_ID }}