fix multi-arch image manifests

Author: zmc

.github/workflows/dev_container.yml

@@ -9,6 +9,10 @@ on:
       - main
   workflow_dispatch:
 
+env:
+  QUAY_URI: quay.io/ceph-infra/teuthology-dev
+  QUAY_TAG: ${{ github.event_name == 'pull_request' && github.head_ref || github.ref_name }}
+
 jobs:
   docker:
     runs-on: ${{ matrix.os }}
@@ -20,23 +24,78 @@ jobs:
           - os: ubuntu-24.04-arm
             python: "3.12"
     steps:
+      - name: Prepare
+        run: |
+          platform=${{ matrix.platform }}
+          echo "PLATFORM_PAIR=${platform//\//-}" >> $GITHUB_ENV
       - name: Checkout
         uses: actions/checkout@v4
       - name: Login to Quay.io
-        if: github.event_name == 'push' && github.ref_name == 'main'
         uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772
         with:
           registry: quay.io
           username: ${{ secrets.QUAY_USERNAME }}
           password: ${{ secrets.QUAY_ROBOT_TOKEN }}
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_IMAGE }}
       - name: Build and push
         uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4
-        env:
-          QUAY_URI: quay.io/ceph-infra/teuthology-dev
-          QUAY_TAG: ${{ github.event_name == 'pull_request' && github.head_ref || github.ref_name }}
         with:
+          platforms: ${{ matrix.platform }}
           context: .
           file: containers/teuthology-dev/Dockerfile
-          push: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
           tags: ${{ env.QUAY_URI }}:${{ env.QUAY_TAG }}
-          outputs: type=image,name=target
+          labels: ${{ steps.meta.outputs.labels }}
+          outputs: type=image,name=target,push-by-digest=true,push=true
+      - name: Export digest
+        run: |
+          mkdir -p ${{ runner.temp }}/digests
+          digest="${{ steps.build.outputs.digest }}"
+          touch "${{ runner.temp }}/digests/${digest#sha256:}"
+      - name: Upload digest
+        uses: actions/upload-artifact@v4
+        with:
+          name: digests-${{ env.PLATFORM_PAIR }}
+          path: ${{ runner.temp }}/digests/*
+          if-no-files-found: error
+          retention-days: 1
+  merge:
+    runs-on: ubuntu-latest
+    needs:
+      - build
+    steps:
+      - name: Download digests
+        uses: actions/download-artifact@v4
+        with:
+          path: ${{ runner.temp }}/digests
+          pattern: digests-*
+          merge-multiple: true
+      - name: Login to Quay.io
+        uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772
+        with:
+          registry: quay.io
+          username: ${{ secrets.QUAY_USERNAME }}
+          password: ${{ secrets.QUAY_ROBOT_TOKEN }}
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_IMAGE }}
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+      - name: Create manifest list and push
+        working-directory: ${{ runner.temp }}/digests
+        run: |
+          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf '${{ env.QUAY_URI }}@sha256:%s ' *)
+      - name: Inspect image
+        run: |
+          docker buildx imagetools inspect ${{ env.QUAY_URI }}:${{ steps.meta.outputs.version }}