1.用kubespray部署一个单节点集群，kubectl get pods -n kube-system，结果：
calico-node-7v8wx 1/1 Running 0 2d
calico-node-c7cv8 1/1 Running 0 2d
但是：
kube-dns-7cdf4f69c7-jcvz7 3/3 Running 979 2d
kube-dns-7cdf4f69c7-m2lfk 3/3 Running 980 2d
DNS不断重启，报10.233.0.1:443连不上。猜测应该是calico有问题。
后面参考这篇文章：https://www.jianshu.com/p/796cd3bf1dfe ￥####不错文章
发现了线索：主机名不能有大写字母
Your hosts’ names must be different. Calico uses hostname as a key in the etcd data, and the etcd data is used to autogenerate the correct BIRD config - so a duplicate hostname will prevent correct BIRD setup.
- calicoctl node status: 查看状态，确认没有问题
用一个例子来演示会更加清晰
