Add docker build/push github action

Signed-off-by: Pawel Sarbinowski <[email protected]>

.github/workflows/docker.yml

@@ -0,0 +1,59 @@
+name: Publish Docker
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set base image env
+        run: |
+          echo "BASE_IMAGE=ghcr.io/marshallwace/prometheus-ucs-exporter" >> $GITHUB_ENV
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - 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: Login to ghcr.io
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: mwam-ci
+          password: ${{ secrets.CR_PAT }}
+
+      - name: Build and Push latest
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/amd64,linux/arm64
+          tags: ${{ env.BASE_IMAGE }}:latest
+          push: ${{ github.event_name != 'pull_request' && github.ref == 'refs/heads/master' }}
+          cache-to: type=local,dest=/tmp/.buildx-cache
+
+      - name: Set tagged image env
+        if: "startsWith(github.ref, 'refs/tags/v')"
+        run: |
+          echo "TAGGED_IMAGE=${BASE_IMAGE}:${GITHUB_REF#refs/tags/v}" >> $GITHUB_ENV
+
+      - name: Build and Push tag
+        uses: docker/build-push-action@v2
+        if: "startsWith(github.ref, 'refs/tags/v')"
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/amd64,linux/arm64
+          tags: ${{ env.TAGGED_IMAGE }}
+          push: ${{ github.event_name != 'pull_request' }}
+          cache-from: type=local,src=/tmp/.buildx-cache