https://my.oschina.net/u/3390908/blog/1649764
1、查看原来node
[root@lab2 ~]# kubectl get no
NAME STATUS ROLES AGE VERSION
10.1.1.111 Ready node 8d v1.11.0
10.1.1.68 Ready node 8d v1.11.0
10.1.1.8 Ready master 8d v1.11.0
2、修改--hostname-override=lab1
[root@lab2 ~]# vi /etc/kubernetes/kubelet
KUBELET_HOSTNAME="--hostname-override=lab1"
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1"
KUBELET_CONFIG="--config=/etc/kubernetes/kubelet-config.yml"
KUBELET_ARGS="--bootstrap-kubeconfig=/etc/kubernetes/kubelet-bootstrap.conf --kubeconfig=/etc/kubernetes/kubelet.conf --cert-dir=/etc/kubernetes/pki --network-plugin=cni --cni-bin-dir=/opt/cni/bin --cni-conf-dir=/etc/cni/net.d --cluster-dns=10.96.0.10 --cluster-domain=cluster.local "
3、重启kubelet 等三分钟查看
[root@lab2 ~]# systemctl daemon-reload && systemctl restart kubelet
[root@lab2 ~]# kubectl get no
NAME STATUS ROLES AGE VERSION
10.1.1.111 Ready node 8d v1.11.0
10.1.1.68 NotReady node 8d v1.11.0
10.1.1.8 Ready master 8d v1.11.0
lab1 NotReady <none> 9m v1.11.0
lab2 NotReady <none> 7m v1.11.0
lab3 NotReady <none> 7m v1.11.0
4、再重启kubelet 等三分钟查看
[root@lab2 ~]# systemctl daemon-reload && systemctl restart kubelet
[root@lab2 ~]# kubectl get no
NAME STATUS ROLES AGE VERSION
10.1.1.111 NotReady node 8d v1.11.0
10.1.1.62 NotReady <none> 8m v1.11.0
10.1.1.68 NotReady node 8d v1.11.0
10.1.1.8 NotReady master 8d v1.11.0
lab1 Ready <none> 13m v1.11.0
lab2 Ready <none> 12m v1.11.0
lab3 Ready <none> 12m v1.11.0
停掉所有node节点的 kubelet
[root@lab3 ~]# systemctl stop kubelet
删除 除了master之外的所有node
[root@lab1 ~]# kubectl delete no 10.1.1.8
[root@lab1 ~]# kubectl delete no 10.1.1.68
[root@lab1 ~]# kubectl delete no 10.1.1.111
[root@lab1 ~]# kubectl delete no lab2
[root@lab1 ~]# kubectl delete no lab3
删除之前通过csr请求后产生的证书、秘钥、kubelet.conf文件
[root@lab1 ~]# rm -rf /etc/kubernetes/kubelet.conf
[root@lab1 ~]# rm -rf /etc/kubernetes/pki/kubelet*
重启所有节点的kubelet
[root@lab1 ~]# systemctl restart kubelet
获取csr
[root@lab1 ~]# kubectl get csr
NAME AGE REQUESTOR CONDITION
node-csr-W8jDxg0LEZZw6U8V1WudhEBRP0qt4ybPSJ-P8XfDzlo 7s kubelet-bootstrap Pending
node-csr-rgnoMPuDdtvfoogsY_zbf1R3KMU_B8M8cBv75AHw8fE 10s kubelet-bootstrap Pending
node-csr-vO6qQvzlI974qUHXVpPu6kMP4eBfKMcBECwqY7xWYu4 17s kubelet-bootstrap Pending
通过证书请求
[root@lab1 ~]# kubectl certificate approve node-csr-W8jDxg0LEZZw6U8V1WudhEBRP0qt4ybPSJ-P8XfDzlo
[root@lab1 ~]# kubectl certificate approve node-csr-rgnoMPuDdtvfoogsY_zbf1R3KMU_B8M8cBv75AHw8fE
[root@lab1 ~]# kubectl certificate approve node-csr-vO6qQvzlI974qUHXVpPu6kMP4eBfKMcBECwqY7xWYu4
5、设置角色
[root@lab2 ~]# kubectl label nodes lab1 node-role.kubernetes.io/master=
[root@lab2 ~]#
[root@lab2 ~]# kubectl label nodes lab2 node-role.kubernetes.io/node=
node/lab2 labeled
[root@lab2 ~]# kubectl label nodes lab3 node-role.kubernetes.io/node=
node/lab3 labeled
# 设置 master 一般情况下不接受负载
kubectl taint nodes lab1 node-role.kubernetes.io/master=true:NoSchedule
[root@lab1 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
lab1 Ready <none> 15m v1.11.0
lab2 Ready <none> 14m v1.11.0
lab3 Ready <none> 14m v1.11.0
6、解决后遗症
执行：
[root@lab1 coredns]# kubectl delete -f coredns.yaml
现象：
[root@lab2 k8s]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-6c65fc5cbb-7xvzs 0/1 ContainerCreating 0 2m
coredns-6c65fc5cbb-kh4zg 0/1 ContainerCreating 0 2m
原因：
修改node名称后的遗留症状
查看pod日志，最后部分
[root@lab2 k8s]# kubectl describe po coredns-6c65fc5cbb-7xvzs -n kube-system
"cni0" already has an IP address different from 10.244.5.1/24
解决：
所有节点执行如下：
rm -rf /var/lib/cni/flannel/* && rm -rf /var/lib/cni/networks/cbr0/* && ip link delete cni0
rm -rf /var/lib/cni/networks/cni0/*
