Use maven to push multi-arch images

* push during build stage as a workaround for buildx
* re-tag the built snapshot if it is a release

.github/workflows/master.yml

@@ -24,9 +24,18 @@ jobs:
       run: |
         echo "app_ver=$(mvn -B help:evaluate -Dexpression=project.version -q -DforceStdout)"
         echo "app_ver=$(mvn -B help:evaluate -Dexpression=project.version -q -DforceStdout)" >> $GITHUB_ENV
+
+# Docker hub action
+    -
+      name: Login to Docker Hub
+      uses: docker/login-action@v3
+      with:
+        username: ${{ secrets.DOCKERHUB_USERNAME }}
+        password: ${{ secrets.DOCKERHUB_TOKEN }}
+
     -
       name: Build with Maven
-      run: mvn -B clean integration-test package assembly:single docker:build
+      run: mvn -B clean integration-test package assembly:single docker:build docker:push
 
 # github_release:
     -
@@ -40,19 +49,7 @@ jobs:
         commit: "master"
         generateReleaseNotes: true
 
-# Docker hub action
-    -
-      name: Login to Docker Hub
-      uses: docker/login-action@v3
-      with:
-        username: ${{ secrets.DOCKERHUB_USERNAME }}
-        password: ${{ secrets.DOCKERHUB_TOKEN }} 
-    -
-      name: push snapshot version
-      run: |
-        echo publishing docker container $app_ver
-        docker push docker.io/obsidiandynamics/kafdrop:$app_ver
     -
       name: push latest if it's a release
       if: ${{ ! endsWith( env.app_ver, '-SNAPSHOT' ) }}
-      run: docker push docker.io/obsidiandynamics/kafdrop:latest
+      run: docker buildx imagetools create docker.io/obsidiandynamics/kafdrop:$app_ver --tag docker.io/obsidiandynamics/kafdrop:latest