openstack magnum error when create cluster

Question

I create Cluster via this Cluster template

openstack coe cluster template create \
  --coe "Kubernetes" \
  --image "fedora-coreos" \
  --flavor "g1.medium" \
  --master-flavor "g1.medium" \
  --volume-driver cinder \
  --docker-storage-driver overlay2 \
  --external-network "External_Net" \
  --floating-ip-enabled \
  --network-driver flannel \
  --docker-volume-size 10 \
  --dns-nameserver 8.8.8.8 \
  --labels="container_runtime=containerd,cinder_csi_enabled=true,cloud_provider_enabled=true" \
  --http-proxy "" \
  --https-proxy "" \
  --no-proxy "" 
  $TEMPLATE_NAME

when i create cluster i got bellow error

Exception during
message handling: magnum.common.exception.GetDiscoveryUrlFailed: Failed to get discovery url from 'https://discovery.etcd.io/new?size=1'.

i set http proxy and everything looks good. any suggestion?