Publish a broker image on release (#111)

Signed-off-by: Taylor Foxhall <[email protected]>

.github/workflows/publish.yaml

@@ -0,0 +1,41 @@
+name: Publish
+
+on:
+  push:
+    # Publish `v*` tags as releases.
+    tags:
+    - v*
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push'
+    steps:
+      - name: Checkout
+        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 DockerHub
+        uses: docker/login-action@v2
+        if: github.event_name != 'pull_request'
+        with:
+          username: ${{ secrets.DOCKERHUB_USER }}
+          password: ${{ secrets.DOCKERHUB_TOKEN  }}
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v4
+        with:
+          images: bloomberg/blazingmq
+      - name: Build and push
+        id: docker_build
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: ./docker/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          target: simple