Attempt to build CI images with mirror

Author: philwebb

ci/tasks/build-ci-image.yml

@@ -14,14 +14,17 @@ caches:
 params:
   CONTEXT: ci-images-git-repo/ci/images
   DOCKERFILE: ci-images-git-repo/ci/images/((ci-image-name))/Dockerfile
+  REGISTRY_MIRRORS: ((docker-hub-mirror))
   DOCKER_HUB_AUTH: ((docker-hub-auth))
+  DOCKER_HUB_MIRROR: ((docker-hub-mirror))
+  DOCKER_HUB_MIRROR_AUTH: ((docker-hub-mirror-auth))
 run:
   path: /bin/sh
   args:
   - "-c"
   - |
     mkdir -p /root/.docker
     cat > /root/.docker/config.json <<EOF
-    { "auths": { "https://index.docker.io/v1/": { "auth": "$DOCKER_HUB_AUTH" }}}
+    { "auths": { "https://index.docker.io/v1/": { "auth": "$DOCKER_HUB_AUTH" }, "$DOCKER_HUB_MIRROR": { "auth": "$DOCKER_HUB_MIRROR_AUTH" }}}
     EOF
     build