Publish Docker images to multiple container registries

[matthewfeickert]

Description

Now that PR #1441 and PR #1442 are in, we can easily publish Docker images to multiple image/container registries using the docker/login-action@v1 GitHub Action. docker/login-action@v1 currently supports the following registries:

• Docker Hub
• GitHub Packages Docker Registry
• GitHub Container Registry
• GitLab
• Azure Container Registry (ACR)
• Google Container Registry (GCR)
• Google Artifact Registry (GAR)
• AWS Elastic Container Registry (ECR)
• AWS Public Elastic Container Registry (ECR)
• OCI Oracle Cloud Infrastructure Registry (OCIR)
• Quay.io

The relevant diff for .github/workflows/docker.yml to publish to the GitHub Container Registry would be something like (c.f. branch ci/add-github-container-registry)

@@ -37,7 +37,7 @@ jobs:
           TAGS="${DOCKER_IMAGE}:${VERSION}"
           TAGS="$TAGS,${DOCKER_IMAGE}:latest,${DOCKER_IMAGE}:sha-${GITHUB_SHA::8}"
           if [ "${{ github.event_name }}" = "release" ]; then
-            TAGS="$TAGS,${DOCKER_IMAGE}:latest-stable"
+            TAGS="$TAGS,${DOCKER_IMAGE}:latest-stable,ghcr.io/${{github.repository}}:latest-stable"
           fi
           echo ::set-output name=version::${VERSION}
           echo ::set-output name=tags::${TAGS}
@@ -55,6 +55,13 @@ jobs:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Test build
         id: docker_build_test
         uses: docker/build-push-action@v2
@@ -99,7 +106,7 @@ jobs:
         with:
           context: .
           file: docker/Dockerfile
-          tags: pyhf/pyhf:latest
+          tags: pyhf/pyhf:latest,ghcr.io/${{github.repository}}:latest
           labels: |
             org.opencontainers.image.source=${{ github.event.repository.html_url }}
             org.opencontainers.image.created=${{ steps.prep.outputs.created }}

[matthewfeickert]

@lukasheinrich @kratsg any thoughts or concerns on this?

[lukasheinrich]

no this looks good!