Add ucs build on older image version (#531)

.github/workflows/stable-build.yml

@@ -92,3 +92,39 @@ jobs:
           export TAG=${{ github.event.inputs.tag }}
           docker buildx bake -f docker-bake.hcl ${{ matrix.images }} --push
         shell: bash
+
+  build-ucs-ubuntu20:
+    name: "Release image: DocumentServer${{ matrix.edition }}-ucs"
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        edition: ["", "-ee"]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKER_HUB_USERNAME }}
+          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+
+      - name: build UCS
+        run: |
+           set -eux
+           export PRODUCT_EDITION=${{ matrix.edition }}
+           export PACKAGE_BASEURL=${{ secrets.REPO_BASEURL }}/testing/ubuntu
+           export DOCKERFILE=Dockerfile
+           export BASE_IMAGE=ubuntu:20.04
+           export PG_VERSION=12
+           export TAG=${{ github.event.inputs.tag }}
+           export PACKAGE_VERSION=$( echo ${TAG} |  sed -E 's/(.*)\./\1-/')
+           docker buildx bake -f docker-bake.hcl documentserver-ucs --push
+        shell: bash