additionally push images to GHCR

Author: wollomatic

.github/workflows/docker-image-release.yaml

@@ -35,6 +35,13 @@ jobs:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Build and push Docker image
         uses: docker/build-push-action@v5
         id: build-and-push
@@ -43,7 +50,11 @@ jobs:
           platforms: linux/amd64,linux/arm/v7,linux/arm64
           push: true
           build-args: VERSION=${{ steps.get_tag.outputs.VERSION }}
-          tags: docker.io/wollomatic/socket-proxy:${{ steps.get_tag.outputs.VERSION }},docker.io/wollomatic/socket-proxy:1
+          tags: |
+            docker.io/wollomatic/socket-proxy:${{ steps.get_tag.outputs.VERSION }}
+            docker.io/wollomatic/socket-proxy:1
+            ghcr.io/wollomatic/socket-proxy:${{ steps.get_tag.outputs.VERSION }}
+            ghcr.io/wollomatic/socket-proxy:1
 
       - name: Sign images for all platforms
         run: cosign sign --yes --key env://COSIGN_PRIVATE_KEY docker.io/wollomatic/socket-proxy:${{ steps.get_tag.outputs.VERSION }}@${{ steps.build-and-push.outputs.digest }}