我曾经juju deploy canonical-kubernetes部署过一个K8S。但是当./kubectl cluster-info按照The Canonical Distribution Of Kubernetes魅力文档所说的那样运行时，会出现以下错误：
Error from server: an error on the server ("<html>\r\n<head><title>502
Bad Gateway</title></head>\r\n<body bgcolor=\"white\">\r\n<center>
<h1>502 Bad Gateway</h1></center>\r\n<hr><center>nginx/1.10.0
(Ubuntu)</center>\r\n</body>\r\n</html>") has prevented the request from succeeding
Juju状态输出：
MODEL CONTROLLER CLOUD/REGION VERSION
default lxd-test localhost/localhost 2.0-rc3
APP VERSION STATUS SCALE CHARM STORE REV OS NOTES
easyrsa 3.0.1 active 1 easyrsa jujucharms 2 ubuntu
elasticsearch active 2 elasticsearch jujucharms 19 ubuntu
etcd 2.2.5 active 3 etcd jujucharms 13 ubuntu
filebeat active 4 …juju ×1