insecure registry for container_infra_prefix not work

magnum version: stable/rocky

I create a cluster template with container_infra_prefix label, which redirect images url to local insecure registry(harbor):

openstack coe cluster template create k8s-cluster-template \
                           --image Fedora-Atomic-27-20180212.2.x86_64 \
                           --keypair testkey \
                           --external-network ext-net \
                           --flavor m1.small \
                           --docker-volume-size 5 \
                           --network-driver flannel \
                           --coe kubernetes \
                           --labels container_infra_prefix=192.168.1.100/magnum/

And I create a cluster with this template, it finally failed with timeout.
So I login into the cluster vm, but no images exist in the vm.