原因：机房断电，导致服务重启

[root@master1 logs]# kubectl get pod
NAME                                READY   STATUS    RESTARTS   AGE
nginx-57d84f57dc-57fkf   1/1     Running   0          75s
[root@master1 logs]# kubectl logs -f nginx-57d84f57dc-b866m 
Error from server (NotFound): pods "nginx-57d84f57dc-b866m" not found
[root@master1 logs]# kubectl exec -it nginx-57d84f57dc-57fkf  -- bash 
Error from server: error dialing backend: dial tcp 10.10.10.14:10250: connect: no route to host
[root@master1 logs]# kubectl exec -it nginx-57d84f57dc-57fkf  -- sh 
Error from server: error dialing backend: dial tcp 10.10.10.14:10250: connect: no route to host

解决：

检查pod所在的node节点服务器是否开启了防火墙

关闭防火墙: 

临时关闭:systemctl stop firewalld
永久关闭:sed -i 's/enforcing/disabled/' /etc/selinux/config