Add publishing of tmp images

.github/workflows/ci.yaml

@@ -507,6 +507,58 @@ jobs:
 
       - uses: codecov/codecov-action@v1
 
+  snapshot-release:
+    name: Publish Reaper image built off this PR
+    # needs: [its-distributed, its-flapping, its-sidecar, its-each]
+    if: ${{ github.event_name == 'pull_request' }}
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.ref }}
+      - name: Setup
+        uses: ./.github/actions/setup
+      - name: Compute version number
+        run: |
+          short_sha=$(git rev-parse --short HEAD)
+          echo "Releasing version (this will become the Docker tag): ${short_sha}-tmp"
+          echo "TMP_DOCKER_TAG=${short_sha}-tmp" >> $GITHUB_ENV
+      - name: Build Reaper
+        run: |
+          MAVEN_OPTS="-Xmx384m" mvn -B install -DskipTests
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+        with:
+          platforms: 'arm64,arm'
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+      - name: Login to DockerHub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USER }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+      - name: Build packages
+        run: ./.github/scripts/before_deploy.sh
+      - name: tags
+        run: |
+          REPO="thelastpickle/cassandra-reaper"
+          echo "Will tag the image as ${REPO}:${TMP_DOCKER_TAG}"
+          echo "DOCKER_TAG_TMP=${REPO}:${TMP_DOCKER_TAG}" >> $GITHUB_ENV
+      - name: Build image and push
+        id: docker_build
+        uses: docker/build-push-action@v4
+        with:
+          file: src/server/src/main/docker/Dockerfile
+          context: .
+          build-args: |
+            SHADED_JAR=${{ env.SHADED_JAR }}
+          push: true
+          tags: ${{ env.DOCKER_TAG_TMP }}
+          platforms: linux/amd64,linux/arm64
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache
+
   release:
     name: Release Reaper
     needs: [its-distributed, its-flapping, its-sidecar, its-each]