ci: publish Docker images to ghcr.io

Author: buchdag

.github/workflows/dockerhub.yml

@@ -39,6 +39,7 @@ jobs:
         uses: docker/metadata-action@v3
         with:
           images: |
+            ghcr.io/nginx-proxy/docker-gen
             nginxproxy/docker-gen
             jwilder/docker-gen
           tags: |
@@ -55,6 +56,7 @@ jobs:
         uses: docker/metadata-action@v3
         with:
           images: |
+            ghcr.io/nginx-proxy/docker-gen
             nginxproxy/docker-gen
             jwilder/docker-gen
           tags: |
@@ -78,6 +80,13 @@ jobs:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      
       - name: Build and push the Alpine based image
         if: ${{ matrix.base == 'alpine' }}
         id: docker_build_alpine
@@ -107,4 +116,4 @@ jobs:
 
       - name: Debian based image digest
         if: ${{ matrix.base == 'debian' }}
-        run: echo ${{ steps.docker_build_debian.outputs.digest }}
+        run: echo ${{ steps.docker_build_debian.outputs.digest }}