Build multi-arch image.

This will build only those architectures that we have runners to build on

.gitlab-ci.yml

@@ -320,4 +320,26 @@ merge-manifests:
       --platforms linux/amd64,linux/arm64,linux/s390x
       --template "${CI_REGISTRY_IMAGE}:${CI_COMMIT_TAG}_ARCH"
       --target "${CI_REGISTRY_IMAGE}:${TAG}"
+      --destination "${CI_REGISTRY_IMAGE}:${TAG}_${ARCH}"
+
+merge-manifests:
+  variables:
+    TAG: latest
+  stage: container-build
+  needs:
+    - job: build-container
+      artifacts: false
+  image:
+      name: mplatform/manifest-tool:alpine
+      entrypoint: [""]
+  script:
+    - if [ -n "$CI_COMMIT_TAG" ]; then export TAG="$CI_COMMIT_TAG"; fi
+    - >-
+      manifest-tool
+      --username="${CI_REGISTRY_USER}"
+      --password="${CI_REGISTRY_PASSWORD}"
+      push from-args
+      --platforms linux/amd64,linux/arm64,linux/s390x
+      --template "${CI_REGISTRY_IMAGE}:${TAG}_ARCH"
+      --target "${CI_REGISTRY_IMAGE}:${TAG}"