Build docker on release

.github/workflows/release-matrix.yml

@@ -42,3 +42,25 @@ jobs:
           asset_content_type: application/x-7z-compressed
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  build-docker:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Docker Buildx
+      id: buildx
+      uses: docker/setup-buildx-action@v1
+    - name: Login to DockerHub
+      if: ${{ github.ref == 'refs/heads/master' }}
+      uses: docker/login-action@v1
+      with:
+        username: ${{ secrets.DOCKERHUB_USERNAME }}
+        password: ${{ secrets.DOCKERHUB_TOKEN }}
+    - name: Build and push Docker images
+      uses: docker/build-push-action@v2.9.0
+      with:
+        github-token: ${{ github.token }}
+        push: ${{ github.ref == 'refs/heads/master' }}
+        tags: |
+          "izuco/multi-downloader-nx:${{ github.event.release.tag_name }}"
+    - name: Image digest
+      run: echo ${{ steps.docker_build.outputs.digest }}