HDDS-11634. Publish images to Docker Hub from GitHub workflow (#33)

Author: adoroszlai

Diff for: .github/workflows/build-and-tag.yaml

@@ -33,18 +33,25 @@ jobs:
     if: ${{ github.ref_type == 'tag' }}
     runs-on: ubuntu-latest
     env:
+      DOCKERHUB_USER: ${{ secrets.DOCKERHUB_USER }}
       IMAGE_ID: ${{ needs.build.outputs.image-id }}
+      REGISTRIES: ghcr.io # docker.io is appended dynamically
     steps:
       - name: Generate tags
         uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81
         with:
           images: |
-            ghcr.io/${{ github.repository_owner }}/ozone-runner
+            ${{ github.repository_owner }}/ozone-runner
           tags: |
             type=ref,event=tag
           flavor: |
             latest=false
 
+      - name: Add Docker Hub to targets
+        if: ${{ env.DOCKERHUB_USER }}
+        run: |
+          echo "REGISTRIES=${{ env.REGISTRIES }} docker.io" >> $GITHUB_ENV
+
       - name: Pull image
         run: |
           docker pull "$IMAGE_ID"
@@ -56,9 +63,19 @@ jobs:
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Login to Docker Hub
+        if: ${{ env.DOCKERHUB_USER }}
+        uses: docker/login-action@9780b0c442fbb1117ed29e0efdff1e18412f7567
+        with:
+          username: ${{ env.DOCKERHUB_USER }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
       - name: Apply tags to existing image
         run: |
-          for tag in $DOCKER_METADATA_OUTPUT_TAGS; do
-            docker tag "$IMAGE_ID" "$tag"
-            docker push "$tag"
+          set -x
+          for registry in $REGISTRIES; do
+            opts="$(echo "$DOCKER_METADATA_OUTPUT_TAGS" | sed "s@^@--tag $registry/@g" | xargs echo)"
+            if [[ -n "$opts" ]]; then
+              docker buildx imagetools create $opts "$IMAGE_ID"
+            fi
           done