为Kubernetes证书续命

Kubernetes证书续命

命令执行后，注意:

1. 无论证书的到期时间如何，都会无条件地续订一年。
2. 证书的SAN等信息基于原证书，无需再次提供。
3. renew执行后，为使更改生效，需要重启控制平面组件。
4. kubeadm alpha certs命令仅支持v1.15及其以上的版本。

命令如下：

# kubeadm  alpha certs renew all
certificate embedded in the kubeconfig file for the admin to use and for kubeadm itself renewed
certificate for serving the Kubernetes API renewed
certificate the apiserver uses to access etcd renewed
certificate for the API server to connect to kubelet renewed
certificate embedded in the kubeconfig file for the controller manager to use renewed
certificate for liveness probes to healtcheck etcd renewed
certificate for etcd nodes to communicate with each other renewed
certificate for serving etcd renewed
certificate for the front proxy client renewed
certificate embedded in the kubeconfig file for the scheduler manager to use renewed

# kubeadm alpha certs check-expiration
CERTIFICATE                                  EXPIRES                      RESIDUAL TIME   EXTERNALLY MANAGED
admin.conf                             Oct 24, 2020 05:25 UTC   364d            no      
apiserver                                Oct 24, 2020 05:25 UTC   364d            no      
apiserver-etcd-client             Oct 24, 2020 05:25 UTC   364d            no      
apiserver-kubelet-client        Oct 24, 2020 05:25 UTC   364d            no      
controller-manager.conf       Oct 24, 2020 05:25 UTC   364d            no      
etcd-healthcheck-client        Oct 24, 2020 05:25 UTC   364d            no      
etcd-peer                              Oct 24, 2020 05:25 UTC   364d            no      
etcd-server                           Oct 24, 2020 05:25 UTC   364d            no      
front-proxy-client                 Oct 24, 2020 05:25 UTC   364d            no      
scheduler.conf                      Oct 24, 2020 05:25 UTC   364d            no