Use docker buildx to ensure images for multi platforms are saved

Author: shaun-nx

.github/workflows/build.yml

@@ -155,7 +155,6 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           annotations: ${{ steps.meta.outputs.annotations }}
           push: ${{ !inputs.dry_run }}
-          load: true
           platforms: ${{ inputs.platforms }}
           cache-from: type=gha,scope=${{ inputs.image }}${{ inputs.build-os != '' && format('-{0}', inputs.build-os) || '' }}
           cache-to: type=gha,scope=${{ inputs.image }}${{ inputs.build-os != '' && format('-{0}', inputs.build-os) || '' }},mode=max
@@ -195,15 +194,22 @@ jobs:
           sarif_file: ${{ steps.scan.outputs.sarif }}
           category: build-${{ inputs.image }}
 
-      - name: Show all image tags for debugging
-        run: echo "${{ steps.meta.outputs.tags }}"
-
-      - name: Save the image as tarball
+      - name: Export and upload images for all platforms
         run: |
-          docker save -o ${{ inputs.image }}.tar localhost:5000/nginx-gateway-fabric/${{ inputs.image }}:${{ steps.meta.outputs.version }}
-
-      - name: Upload the image artifact
+          # Remove spaces and split platforms by comma
+          platforms=$(echo "${{ inputs.platforms }}" | tr -d ' ' | tr ',' ' ')
+          for platform in $platforms; do
+          # Replace / with - for tarball name (e.g., linux/amd64 -> linux-amd64)
+          plat_tag=$(echo "$platform" | tr '/' '-')
+          # Create a local reference for the platform
+          docker buildx imagetools create --tag tempimg-$plat_tag ghcr.io/${{ github.repository_owner }}/nginx-gateway-fabric/${{ inputs.image }}:${{ steps.meta.outputs.version }} --platform $platform
+          # Export the image as a tarball
+          docker buildx imagetools export tempimg-$plat_tag > ${{ inputs.image }}-$plat_tag.tar
+          done
+
+      - name: Upload all image artifacts
         uses: actions/upload-artifact@v4
         with:
-          name: ${{ inputs.image }}
-          path: ${{ inputs.image }}.tar
+          name: ${{ inputs.image }}-images
+          path: ${{ inputs.image }}-*.tar
+

.github/workflows/ci.yml

@@ -416,11 +416,13 @@ jobs:
       fail-fast: false
       matrix:
         image: [ngf, nginx, operator]
+        platform: ["linux/amd64", "linux/arm64"]
     # if: ${{ github.event_name == 'pull_request' && github.event_pull_request.base.ref == 'main' || (github.event_name == 'push' && github.ref == 'refs/heads/main') || (inputs.is_production_release == true) }}
     uses: ./.github/workflows/openshift-certification.yml
     with:
       runner: ubuntu-24.04
       image: ${{ matrix.image }}
+      platform: ${{ matrix.platform }}
     permissions:
       contents: read
       packages: read

.github/workflows/openshift-certification.yml

@@ -10,6 +10,9 @@ on:
       image:
         required: true
         type: string
+      platform:
+        required: true
+        type: string
 
 defaults:
   run:
@@ -34,14 +37,14 @@ jobs:
     - name: Download image artifact
       uses: actions/download-artifact@v4
       with:
-        name: ${{ inputs.image }}
+        name: ${{ inputs.image }}-images  # or ${{ inputs.image }}-linux-${{ inputs.platform | tr '/' '-' }}
 
     - name: Load image into Docker
-      run: docker load -i ${{ inputs.image }}.tar
+      run: docker load -i ${{ inputs.image }}-${{ inputs.platform | tr '/' '-' }}.tar
 
     - name: Retag image for preflight
       run: |
-        loaded_tag="localhost:5000/nginx-gateway-fabric/${{ inputs.image }}"
+        loaded_tag="ghcr.io/${{ github.repository_owner }}/nginx-gateway-fabric/${{ inputs.image }}:${{ inputs.image_version }}"
         preflight_tag="${{ inputs.image }}:ubi"
         docker tag "$loaded_tag" "$preflight_tag"