pages: upload to preview bucket (#510)

* pages: upload to preview bucket

* try the preview status

* try with checks-action

* try with status permission

.github/workflows/pages.yml

@@ -124,6 +124,7 @@ jobs:
       - pages-swift
     permissions:
       contents: write
+      statuses: write
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
@@ -161,3 +162,32 @@ jobs:
             git commit -m "Update docs from $GITHUB_REF_NAME (${GITHUB_SHA::7})"
             git push origin gh-pages
           fi
+
+      - name: "Preview: copy to staging dir"
+        if: "!github.event.pull_request.head.repo.fork && github.ref != 'refs/heads/main'"
+        run: cp -r . /tmp/preview-files && rm -rf /tmp/preview-files/.git
+
+      - name: "Preview: auth to GCS"
+        if: "!github.event.pull_request.head.repo.fork && github.ref != 'refs/heads/main'"
+        uses: "google-github-actions/auth@v0"
+        with:
+          credentials_json: "${{ secrets.GCS_PREVIEW_KEY_JSON }}"
+
+      - name: "Preview: push to preview bucket"
+        if: "!github.event.pull_request.head.repo.fork && github.ref != 'refs/heads/main'"
+        uses: "google-github-actions/upload-cloud-storage@v0"
+        with:
+          path: "/tmp/preview-files"
+          parent: false
+          destination: "foxglove-mcap-dev-preview/${{ github.ref }}"
+
+      - name: "Preview: display URL"
+        if: "!github.event.pull_request.head.repo.fork && github.ref != 'refs/heads/main'"
+        uses: Sibz/github-status-action@v1
+        with:
+          authToken: ${{secrets.GITHUB_TOKEN}}
+          context: "Pages Preview"
+          description: "Available in details"
+          state: "success"
+          sha: ${{github.event.pull_request.head.sha || github.sha}}
+          target_url: "https://storage.googleapis.com/foxglove-mcap-dev-preview/${{ github.ref }}/index.html"