Add improved workflow for pushing Docker images

.github/workflows/docker-push.yml

@@ -0,0 +1,122 @@
+name: "Docker Push"
+
+on:
+  release:
+    types: [published]
+  schedule:
+    - cron: '30 12 * * *'
+
+permissions:
+  packages: write
+  contents: read
+
+env:
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  Docker:
+    name: Docker Build & Publish
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Prepare metadata for build
+        id: metadata
+        run: |
+          rev=$(git rev-list --tags --max-count=1)
+          version=$(git describe --tags "$rev" | tr -d 'v')
+
+          if [[ -z "$version" ]] ; then
+            echo "::error::Can't find version info"
+            exit 1
+          fi
+
+          docker_file="Dockerfile"
+          base_image=$(grep 'FROM ' $docker_file | tail -1 | cut -f2 -d' ')
+
+          if [[ -z "$base_image" ]] ; then
+            echo "::error::Can't extract base image info"
+            exit 1
+          fi
+
+          echo "::set-output name=version::$version"
+          echo "::set-output name=dockerfile::$docker_file"
+          echo "::set-output name=baseimage::$base_image"
+
+          echo -e "\033[34mVersion:\033[0m    $version"
+          echo -e "\033[34mDockerfile:\033[0m $docker_file"
+          echo -e "\033[34mBase image:\033[0m $base_image"
+
+      - name: Check if build/rebuild is required
+        id: build_check
+        run: |
+          if [[ "${{github.event_name}}" == "release" ]] ; then
+            echo "::set-output name=build::true"
+            exit 0
+          fi
+
+          echo -e "::group::\033[34mDownloading built image…\033[0m"
+
+          if ! docker pull ghcr.io/${{env.IMAGE_NAME}}:latest ; then
+            echo "::error::Can't download image ghcr.io/${{env.IMAGE_NAME}}:latest"
+            exit 1
+          fi
+
+          echo "::endgroup::"
+          echo -e "::group::\033[34mDownloading base image…\033[0m"
+
+          if ! docker pull ${{steps.metadata.outputs.baseimage}} ; then
+            echo "::error::Can't download image ${{steps.metadata.outputs.baseimage}}"
+            exit 1
+          fi
+
+          echo "::endgroup::"
+
+          base_layer=$(docker inspect "${{steps.metadata.outputs.baseimage}}" | jq -r '.[0].RootFS.Layers[-1]')
+
+          if [[ -z "$base_layer" ]] ; then
+            echo "::error::Can't extract layers info from base image"
+            exit 1
+          fi
+
+          if ! docker inspect "ghcr.io/${{env.IMAGE_NAME}}:latest" | jq -r '.[0].RootFS.Layers' | grep -q "$base_layer" ; then
+            echo "::warning::Rebuild image (reason: base image rebuilt)"
+            echo "::set-output name=build::true"
+            exit 0
+          fi
+
+      - name: Build and push Docker image
+        if: ${{ steps.build_check.outputs.build == 'true' }}
+        uses: docker/build-push-action@v3
+        with:
+          push: true
+          context: .
+          file: ${{steps.metadata.outputs.dockerfile}}
+          tags: |
+            ghcr.io/${{env.IMAGE_NAME}}:${{steps.metadata.outputs.version}}
+            ghcr.io/${{env.IMAGE_NAME}}:latest
+            ${{env.IMAGE_NAME}}:${{steps.metadata.outputs.version}}
+            ${{env.IMAGE_NAME}}:latest
+
+      - name: Show info about built Docker image
+        uses: essentialkaos/docker-info-action@v1
+        with:
+          image: ${{env.IMAGE_NAME}}:latest
+          show-labels: true