1，虚拟机重启后使用kubectl命令报错

The connection to the server x.x.x.x:6443 was refused - did you specify the right host or port?

这是因为swap没有关。

#1，关闭swap
swapoff -a
#2，设置swap开机不启动
#将文件中的/dev/mapper/centos-swap swap swap defaults 0 0这一行注释掉
vi /etc/fstab

#3,同时调整k8s的swappiness参数
vi /etc/sysctl.d/k8s.conf
#添加一行vm.swappiness=0

#4，执行
sysctl -p /etc/sysctl.d/k8s.conf

2，如果没有关闭防火墙，把防火墙也关了

systemctl stop firewalld

并设置开机不启动

systemctl disable firewalld

3，kubectl get pods正常，但是发现dashboard打不开。

#1，查看dashboard状态发现Node is not ready
kubectl -n kubernetes-dashboard get service kubernetes-dashboard

Events:
  Type     Reason        Age    From             Message
  ----     ------        ----   ----             -------
  Warning  NodeNotReady  9m27s  node-controller  Node is not ready

#2，查看node状态发现node的kube-proxy没有启动
kubectl describe node k8s-node1

Events:
  Type     Reason                           Age                      From                   Message
  ----     ------                           ----                     ----                   -------
  Warning  FailedToStartProxierHealthcheck  33h (x40850 over 3d18h)  kube-proxy, k8s-node1  failed to start proxier healthz on 0.0.0.0:10256: listen tcp 0.0.0.0:10256: bind: address already in use

#3，到node虚拟机上执行 docker ps，发现容器为空。
#启动kubelet，并设置为开机启动
systemctl start kubelet
systemctl enable kubelet

#等待一会docker ps发现kubelet的相关服务启动，dashboard正常打开。