docker: push images to GHCR too

use numeric id for user inside Dockerfile

.github/workflows/docker.yml

@@ -18,7 +18,12 @@ jobs:
       matrix:
         os:
           - ubuntu-latest
-        docker_pkg: [debian, alpine]
+        docker_pkg:
+          - debian
+          - alpine
+        docker_image:
+          - drakkan/sftpgo
+          - ghcr.io/drakkan/sftpgo
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -34,7 +39,6 @@ jobs:
       - name: Gather image information
         id: info
         run: |
-          DOCKER_IMAGE=drakkan/sftpgo
           VERSION=noop
           DOCKERFILE=Dockerfile
           MINOR=""
@@ -80,6 +84,7 @@ jobs:
           echo ::set-output name=sha::${GITHUB_SHA::8}
         env:
           DOCKER_PKG: ${{ matrix.docker_pkg }}
+          DOCKER_IMAGE: ${{ matrix.docker_image }}
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
@@ -92,7 +97,15 @@ jobs:
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
-        if: github.event_name != 'pull_request'
+        if: ${{ github.event_name != 'pull_request' && matrix.docker_image == 'drakkan/sftpgo' }}
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.CR_PAT }}
+        if: ${{ github.event_name != 'pull_request' && matrix.docker_image == 'ghcr.io/drakkan/sftpgo' }}
 
       - name: Build and push
         uses: docker/build-push-action@v2