Update docker push action to v2

.github/workflows/docker_push.yml

@@ -1,27 +1,27 @@
 name: Publish Docker image
 on:
   workflow_dispatch:
-  release:
-    types: [published]
   push:
     branches:
-      - master
+      - 'master'
+    tags:
+      - 'v*'
 
 jobs:
-  push_to_registry:
-    name: Push Docker image to Docker Hub
+  docker_push:
     runs-on: ubuntu-latest
     steps:
-      - name: Check out the repo
+      - name: Checkout
         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: Docker meta
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: seitenwerke/nginx-proxy
 
       - name: Login to DockerHub
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v1
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
@@ -30,7 +30,7 @@ jobs:
       - name: Push debian image to Docker Hub
         uses: docker/build-push-action@v2
         with:
-          file: Dockerfile
-          platforms: linux/amd64,linux/arm64,linux/arm/v7
-          repository: seitenwerke/nginx-proxy
-          tag_with_ref: true
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}