kubernetes集群报 unable to load bootstrap kubeconfig处置思路

一.现状和问题现象

公司kubernetes集群是通过kubeadm工具安装的，使用1年之后证书到期。在 kubernetes control plane maste节点服务器上运行 kubeadm certs renew all 命令更新证书后，kubelet 无法正常启动，报错日志如下

Failed to run kubelet" err="failed to run Kubelet: unable to load bootstrap kubeconfig: stat /etc/kubernetes/bootstrap-kubelet.conf: no such file or directory

 二.处置思路

针对master节点

1.针对单master节点或者多master节点但是无VIP地址的
$ cd /etc/kubernetes/pki/
$ mv {apiserver.crt,apiserver-etcd-client.key,apiserver-kubelet-client.crt,front-proxy-ca.crt,front-proxy-client.crt,front-proxy-client.key,front-proxy-ca.key,apiserver-kubelet-client.key,apiserver.key,apiserver-etcd-client.crt} ~/
$ kubeadm init phase certs all
$ cd /etc/kubernetes/
$ mv {admin.conf,controller-manager.conf,kubelet.conf,scheduler.conf} ~/
$ kubeadm init phase kubeconfig all
$ reboot  #本步骤不必须，如果有异常可以重启
$ cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
 
2.针对多master节点高可用，存在VIP地址的,下面的VIP地址替换成对应的IP
$ kubeadm init phase certs all --control-plane-endpoint "VIP:6443"
$ kubeadm init phase kubeconfig all --control-plane-endpoint "VIP:6443"

这对worker节点

登录到对应的worker节点，拷贝 admin.conf 到 kubelet.conf ，再重新启动kubelet服务
 
cp -a /etc/kubernetes/admin.conf /etc/kubernetes/kubelet.conf
 
systemctl daemon-reload && systemctl restart kubelet
 
#如果以上处理异常，可针对worker节点删除，重新添加