Push testing image to GHCR, sign GHCR images

Author: wollomatic

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

@@ -36,6 +36,13 @@ 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: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Build and push Docker image
         uses: docker/build-push-action@v5
         id: build-and-push
@@ -44,10 +51,20 @@ jobs:
           platforms: linux/amd64,linux/arm64
           push: true
           build-args: VERSION=testing-${{ github.sha }}
-          tags: docker.io/wollomatic/socket-proxy:testing,docker.io/wollomatic/socket-proxy:testing-${{ github.sha }}
+          tags: | 
+            docker.io/wollomatic/socket-proxy:testing
+            docker.io/wollomatic/socket-proxy:testing-${{ github.sha }}
+            ghcr.io/wollomatic/socket-proxy:testing
+            ghcr.io/wollomatic/socket-proxy:testing-${{ github.sha }}
+
+      - name: Sign Docker Hub image
+        run: cosign sign --yes --recursive --key env://COSIGN_PRIVATE_KEY docker.io/wollomatic/socket-proxy:testing-${{ github.sha }}@${{ steps.build-and-push.outputs.digest }}
+        env:
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+          COSIGN_PASSWORD: ${{ secrets.COSIGN_PASSWORD }}
 
-      - name: Sign images for all platforms
-        run: cosign sign --yes --recursive --key env://COSIGN_PRIVATE_KEY docker.io/wollomatic/socket-proxy:${{ steps.get_tag.outputs.VERSION }}@${{ steps.build-and-push.outputs.digest }}
+      - name: Sign GitHub Container Registry image
+        run: cosign sign --yes --recursive --key env://COSIGN_PRIVATE_KEY ghcr.io/wollomatic/socket-proxy:testing-${{ github.sha }}@${{ steps.build-and-push.outputs.digest }}
         env:
           COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
           COSIGN_PASSWORD: ${{ secrets.COSIGN_PASSWORD }}