安装教程：CentOS7安装k8s - 下课后我要去放牛 - 博客园 (cnblogs.com)
执行 kubectl get nodes 常见异常处理：
1、Error: the server doesn't have a resource type "nodes"
处理方法：执行如下命令行
sudo cp /etc/kubernetes/admin.conf ~/.kube/config
2、Error: Unable to connect to the server: x509: certificate signed by unknown authority
处理方法：kubectl get nodes 后面加上 --insecure-skip-tls-verify
kubectl get nodes --insecure-skip-tls-verify
