feat(multi-arch): combine architecture specific images into a multi-arch manifest

Author: hutchic

.github/workflows/release.yaml

@@ -11,6 +11,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.event_name == 'pull_request' }}
 
+env:
+  image_name: template-github-release
+
 jobs:
   release:
     name: Create Release
@@ -58,7 +61,7 @@ jobs:
       id: meta
       uses: docker/metadata-action@v4
       with:
-        images: ghcr.io/kong/template-github-release
+        images: ghcr.io/kong/${{ env.image_name }}
         sep-tags: ' '
         flavor: |
           suffix=-${{ matrix.architecture }}-${{ matrix.ostype }}
@@ -71,7 +74,7 @@ jobs:
       if: ${{ needs.release.outputs.published == 'true' }}
       run: |
         for tag in ${{ steps.meta.outputs.tags }}; do \
-          docker tag ghcr.io/template-github-release:build-$ARCHITECTURE-$OSTYPE $tag && \
+          docker tag ghcr.io/${{ env.image_name }}:build-$ARCHITECTURE-$OSTYPE $tag && \
           docker push $tag; \
         done
     - name: Archive the package
@@ -84,3 +87,20 @@ jobs:
       with:
         tag_name: ${{ needs.release.outputs.release-git-tag }}
         files: ${{ matrix.architecture }}-${{ matrix.ostype }}.tar.gz
+
+  multi-arch:
+    needs: artifacts
+    name: Create Release Artifacts
+    strategy:
+      matrix:
+        ostype: [linux-gnu, linux-musl]
+    runs-on: ubuntu-latest
+    steps:
+    - name: Combine per architecture images into a single multi-arch manifest
+      run: |
+        docker pull ghcr.io/kong/${{ env.image_name }}:${{ needs.release.outputs.release-git-tag }}-aarch64-${{ matrix.ostype }}
+        docker pull ghcr.io/kong/${{ env.image_name }}:${{ needs.release.outputs.release-git-tag }}-x86_64-${{ matrix.ostype }}
+        docker manifest ghcr.io/kong/${{ env.image_name }}:${{ needs.release.outputs.release-git-tag }}-${{ matrix.ostype }} \
+          ghcr.io/kong/${{ env.image_name }}:${{ needs.release.outputs.release-git-tag }}-aarch64-${{ matrix.ostype }} \
+          ghcr.io/kong/${{ env.image_name }}:${{ needs.release.outputs.release-git-tag }}-x86_64-${{ matrix.ostype }}
+        ghcr.io/kong/${{ env.image_name }}:${{ needs.release.outputs.release-git-tag }}-${{ matrix.ostype }}