Add pipeline for tagging

.github/workflows/tag.yaml

@@ -0,0 +1,47 @@
+name: ci
+
+on:
+  create:
+    tag:
+      - '*'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+
+      - uses: actions/checkout@v2
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Get the version
+        id: get_version
+        run: echo ::set-output name=version::${GITHUB_REF/refs\/tags\//}
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        id: docker_build
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          platforms: linux/amd64,linux/arm64
+          tags: dkrizic/observium:latest,dkrizic/observium:${{ steps.get_version.outputs.version }}
+      - name: Image digest
+        run: echo ${{ steps.docker_build.outputs.digest }}
+
+      - name: Docker Hub Description
+        uses: peter-evans/dockerhub-description@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+          repository: dkrizic/observium
+          short-description: ${{ github.event.repository.description }}