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近期因为ip地址洁癖，需要将一个在线的k8s集群地址替换成另一个顺序地址。过程记录如下：

  • 思路：
  • 1、修改nfs服务器配置，允许新ip访问
  • 2、停一台master 服务器，改IP，重新加入集群做master
  • 3、重复操作直到master节点全部更换ip
  • 4、停止部分node，修改ip，加入集群。
  • 5、停止剩下的node，修改ip，加入集群

删除主节点 (master 主机执行)

# kubectl get nodes
NAME          STATUS   ROLES    AGE    VERSION
k8s-master    Ready    master   195d   v1.17.1
k8s-worker1   Ready    <none>   194d   v1.17.1
k8s-worker2   Ready    <none>   194d   v1.17.1
k8s-worker3   Ready    <none>   181d   v1.17.1
k8s-worker4   Ready    master   181d   v1.17.1
k8s-worker5   Ready    <none>   181d   v1.17.1
k8s-worker6   Ready    master   181d   v1.17.1

# kubectl drain k8s-worker6 --delete-local-data --force --ignore-daemonsets
kubectl drain k8s-worker6 --delete-local-data --force --ignore-daemonsets
node/k8s-worker6 cordoned
node/k8s-worker6 drained

# kubectl delete node k8s-worker6
node "k8s-worker6" deleted

# kubectl get nodes
NAME          STATUS   ROLES    AGE    VERSION
k8s-master    Ready    master   195d   v1.17.1
k8s-worker1   Ready    <none>   194d   v1.17.1
k8s-worker2   Ready    <none>   194d   v1.17.1
k8s-worker3   Ready    <none>   181d   v1.17.1
k8s-worker4   Ready    master   181d   v1.17.1
k8s-worker5   Ready    <none>   181d   v1.17.1

删除失效的etcd (master 主机执行)

# docker exec -it $(docker ps -f name=etcd_etcd -q) /bin/sh
etcdctl --endpoints 127.0.0.1:2379 --cacert /etc/kubernetes/pki/etcd/ca.crt --cert /etc/kubernetes/pki/etcd/server.crt --key /etc/kubernetes/pki/etcd/server.key member list

75586071aa4f50d0, started, k8s-master, https://10.25.207.74:2380, https://10.25.207.74:2379, false
8beff87c2c833c9d, started, k8s-worker4, https://10.25.207.78:2380, https://10.25.207.78:2379, false
ae6c4d540db7935b, started, k8s-worker6, https://10.25.207.80:2380, https://10.25.207.80:2379, false

在容器中将这台服务器从 etcd 集群中移除

etcdctl --endpoints 127.0.0.1:2379 --cacert /etc/kubernetes/pki/etcd/ca.crt --cert /etc/kubernetes/pki/etcd/server.crt --key /etc/kubernetes/pki/etcd/server.key member remove ae6c4d540db7935b

重置本机k8环境 ( 变更主机执行)

kubeadm reset

新ip后更换hostname ( 变更主机执行)

export server=k8s-master3
hostnamectl --static set-hostname $server;hostnamectl --transient set-hostname $server

k8s master 获取证书 (master 主机执行)

# kubeadm init phase upload-certs --upload-certs
[upload-certs] Using certificate key:
cb7e8c0b643963eca9bcfa90d35390cc3de8d38398e0ea354e25311f380c86ea

# kubeadm token create --print-join-command
kubeadm join apiserver.k8s.com:6443 --token yu6jh8.g4xl2a3nbgr9jo52     --discovery-token-ca-cert-hash sha256:9fc7ce12374c9b1cc87b4acef89682d3a5bc57ccb48f04fa9e4693609e4bb46d

加入集群 ( 变更主机执行)

kubeadm join apiserver.k8s.com:6443 --token yu6jh8.g4xl2a3nbgr9jo52 \
    --discovery-token-ca-cert-hash sha256:9fc7ce12374c9b1cc87b4acef89682d3a5bc57ccb48f04fa9e4693609e4bb46d \
    --control-plane --certificate-key 5feca6f707cd03d4329a9fb4b598bd14ec886413dc41f1e06b81acf7ddd0ff8f \
    --v=5

# mkdir -p $HOME/.kube
# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
# chown $(id -u):$(id -g) $HOME/.kube/config

# kubectl get nodes
NAME          STATUS   ROLES    AGE    VERSION
k8s-master    Ready    master   195d   v1.17.1
k8s-master3   Ready    master   40s    v1.17.1
k8s-worker1   Ready    <none>   195d   v1.17.1
k8s-worker2   Ready    <none>   195d   v1.17.1
k8s-worker3   Ready    <none>   182d   v1.17.1
k8s-worker4   Ready    master   182d   v1.17.1
k8s-worker5   Ready    <none>   182d   v1.17.1

更换节点IP

删除节点

[root@k8s-master ~]# kubectl  get nodes
NAME          STATUS   ROLES    AGE    VERSION
k8s-master    Ready    master   26d    v1.17.1
k8s-master2   Ready    master   26d    v1.17.1
k8s-master3   Ready    master   27d    v1.17.1
k8s-worker1   Ready    <none>   222d   v1.17.1
k8s-worker2   Ready    <none>   222d   v1.17.1
k8s-worker3   Ready    <none>   209d   v1.17.1
k8s-worker5   Ready    <none>   209d   v1.17.1
删除节点
[root@k8s-master ~]# kubectl  delete nodes k8s-worker5
node "k8s-worker5" deleted
[root@k8s-master ~]# kubectl  delete nodes k8s-worker3
node "k8s-worker3" deleted

被删除节点上清除数据

ssh k8s-worker5
kubeadm reset
rm -rf /etc/cni/net.d
rm -rf $HOME/.kube/config
rm -rf /etc/kubernetes/

加入节点

kubeadm token create --print-join-command

kubeadm join apiserver.k8s.com:6443 --token of5d4s.jdr4bho8uhg0yjax --discovery-token-ca-cert-hash sha256:9fc7ce12374c9b1cc87b4acef89682d3a5bc57ccb48f04fa9e4693609e4bb46d
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