Restore dashbaord mainnet workflow

Restore dahsboard mainnet workflow to the projects so that we can see the
mainnet preview before a release.

.github/workflows/dashboard-v1-mainnet.yml

@@ -0,0 +1,111 @@
+name: Token Dashboard / Mainnet
+
+on:
+  pull_request:
+    branches: [main]
+    paths:
+      - solidity-v1/dashboard/**
+
+# For pull_request_target:
+#  - Checkout with repository set to PR repo, ref same (see
+#    https://github.com/actions/checkout#usage).
+#  - Trigger from issue comment?
+
+jobs:
+  build-docker:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Cache Docker layers
+        uses: actions/cache@v2
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-
+
+      - name: Build Docker Build Image
+        uses: docker/build-push-action@v2
+        with:
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache-new
+
+      - # Temp fix - move cache instead of copying (added below step and
+        # modified value of `cache-to`).
+        # https://github.com/docker/build-push-action/issues/252
+        # https://github.com/moby/buildkit/issues/1896
+        # Without the change some jobs were failing with `no space left on device`
+        name: Move cache
+        run: |
+          rm -rf /tmp/.buildx-cache
+          mv /tmp/.buildx-cache-new /tmp/.buildx-cache
+
+  build-and-deploy:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.11.x]
+
+    if: startsWith(github.head_ref, 'releases/mainnet/token-dashboard/')
+    defaults:
+      run:
+        working-directory: solidity-v1/dashboard
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+      # This step forces Git to download dependencies using `https://` protocol,
+      # even if `package-lock.json` refers to some package via `git://`. Using
+      # `git://` is no longer supported by GH. One of the `dashboard`
+      # dependencies by default uses `git://` and we needed to manually remove
+      # it every time it re-appeared in the lock file. Now even if it does,
+      # the `npm ci` will not fail.
+      - name: Configure git to don't use unauthenticated protocol
+        run: git config --global url."https://".insteadOf git://
+      - run: npm ci
+      #- run: npm run lint
+      #- if: github.event_name == 'push' TODO uncomment when mainnet builds happen this way
+      #  run: npm run build --if-present
+      - if: github.event_name == 'pull_request'
+        run: npm run build
+        env:
+          PUBLIC_URL: /${{ github.head_ref }}
+      # A push event is a main merge; deploy to primary bucket.
+      # TODO uncomment when mainnet builds happen this way
+      #- if: github.event_name == 'push'
+      #  name: Deploy Main to GCP
+      #  uses: thesis/[email protected]
+      #  with:
+      #    service-key: ${{ secrets.KEEP_DASHBOARD_UPLOADER_SERVICE_KEY_JSON }}
+      #    project: keep-prd-210b
+      #    bucket-name: dashboard.keep.network
+      #    build-folder: solidity-v1/dashboard/build
+      # A pull_request event is a PR; deploy to preview bucket.
+      - if: github.event_name == 'pull_request'
+        name: Deploy PR preview to GCP
+        uses: thesis/[email protected]
+        with:
+          service-key: ${{ secrets.KEEP_DASHBOARD_UPLOADER_SERVICE_KEY_JSON_BASE64 }}
+          project: keep-prd-210b
+          bucket-name: preview.dashboard.keep.network
+          bucket-path: ${{ github.head_ref }}
+          build-folder: solidity-v1/dashboard/build
+      # A pull_request event is a PR; leave a comment with the preview URL.
+      - if: github.event_name == 'pull_request'
+        name: Post preview URL to PR
+        uses: actions/github-script@v5
+        with:
+          script: |
+            github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: 'Preview uploaded to https://preview.dashboard.keep.network/${{ github.head_ref }}/.'
+            })