客户环境虚拟机故障导致其中一台master节点宕机，重启操作系统后，kubelet服务无法启动。
启动日志报错
E0527 17:30:41.411880 2279924 bootstrap.go:255] unable to load TLS certificates from existing bootstrap client config read from /etc/kubernetes/kubelet.conf: data does not contain any valid RSA or ECDSA certificates
E0527 17:30:41.411929 2279924 server.go:292] "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"通过检查/etc/kubernetes/kubelet.conf文件，发现/var/lib/kubelet/pki/kubelet-client-current.pem对应软连接的文件为空，导致kubelet失败。
# ll
总用量 8
-rw------- 1 root root 1114 7月 14 2025 kubelet-client-2025-07-14-11-31-33.pem
lrwxrwxrwx 1 root root 59 5月 6 10:40 kubelet-client-current.pem -> /var/lib/kubelet/pki/kubelet-client-2026-05-06-10-40-34.pem
-rw------- 1 root root 1155 7月 14 2025 kubelet-server-2025-07-14-11-45-07.pem
lrwxrwxrwx 1 root root 59 7月 14 2025 kubelet-server-current.pem -> /var/lib/kubelet/pki/kubelet-server-2025-07-14-11-45-07.pem执行以下操作，重启kubelet即可。
cd
rm -f kubelet-client-2026-05-06-10-40-34.pem
cp kubelet-client-2025-07-14-11-31-33.pem kubelet-client-2026-05-06-10-40-34.pem