1、查看证书有效期
kubeadm certs check-expiration
更新证书前：
[check-expiration] Reading configuration from the cluster...
[check-expiration] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'CERTIFICATE EXPIRES RESIDUAL TIME CERTIFICATE AUTHORITY EXTERNALLY MANAGED
admin.conf Mar 29, 2025 09:55 UTC 362d ca no
apiserver Mar 29, 2025 09:55 UTC 362d ca no
apiserver-etcd-client Mar 29, 2025 09:55 UTC 362d etcd-ca no
apiserver-kubelet-client Mar 29, 2025 09:55 UTC 362d ca no
controller-manager.conf Mar 29, 2025 09:55 UTC 362d ca no
etcd-healthcheck-client Mar 29, 2025 09:55 UTC 362d etcd-ca no
etcd-peer Mar 29, 2025 09:55 UTC 362d etcd-ca no
etcd-server Mar 29, 2025 09:55 UTC 362d etcd-ca no
front-proxy-client Mar 29, 2025 09:55 UTC 362d front-proxy-ca no
scheduler.conf Mar 29, 2025 09:55 UTC 362d ca no
super-admin.conf Mar 29, 2025 09:55 UTC 362d ca no CERTIFICATE AUTHORITY EXPIRES RESIDUAL TIME EXTERNALLY MANAGED
ca Mar 27, 2034 09:55 UTC 9y no
etcd-ca Mar 27, 2034 09:55 UTC 9y no
front-proxy-ca Mar 27, 2034 09:55 UTC 9y no
更新证书后
[check-expiration] Reading configuration from the cluster...
[check-expiration] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'CERTIFICATE EXPIRES RESIDUAL TIME CERTIFICATE AUTHORITY EXTERNALLY MANAGED
admin.conf Apr 01, 2025 06:50 UTC 364d ca no
apiserver Apr 01, 2025 06:50 UTC 364d ca no
apiserver-etcd-client Apr 01, 2025 06:50 UTC 364d etcd-ca no
apiserver-kubelet-client Apr 01, 2025 06:50 UTC 364d ca no
controller-manager.conf Apr 01, 2025 06:50 UTC 364d ca no
etcd-healthcheck-client Apr 01, 2025 06:50 UTC 364d etcd-ca no
etcd-peer Apr 01, 2025 06:50 UTC 364d etcd-ca no
etcd-server Apr 01, 2025 06:50 UTC 364d etcd-ca no
front-proxy-client Apr 01, 2025 06:50 UTC 364d front-proxy-ca no
scheduler.conf Apr 01, 2025 06:50 UTC 364d ca no
super-admin.conf Apr 01, 2025 06:50 UTC 364d ca no CERTIFICATE AUTHORITY EXPIRES RESIDUAL TIME EXTERNALLY MANAGED
ca Mar 27, 2034 09:55 UTC 9y no
etcd-ca Mar 27, 2034 09:55 UTC 9y no
front-proxy-ca Mar 27, 2034 09:55 UTC 9y no
2、备份(每台机器有的都要备份)
cp -rp /etc/kubernetes /etc/kubernetes.bak
cp -rp /var/lib/etcd /var/lib/etcd.bak
cp -a ~/.kube ~/.kube_bak
3、重新生成证书，使用该命令不用提前删除过期证书(所有master节点都要做)
kubeadm certs renew all
4、再查看证书有效期
openssl x509 -in /etc/kubernetes/pki/apiserver.crt -noout -text |grep 'Not'Not Before: Mar 29 09:50:37 2024 GMTNot After : Apr 1 06:50:43 2025 GMT
5、重启四大组件（所有master操作）
docker ps | grep -E 'k8s_kube-apiserver|k8s_kube-controller-manager|k8s_kube-scheduler|k8s_etcd_etcd' | awk -F ' ' '{print $1}' | xargs docker restart
6、更新用户证书凭证（所有master操作）
cp /etc/kubernetes/admin.conf ~/.kube/config
7、所有节点重启kubelet
systemctl restart kubelet
8、检测状态，成功
systemctl status kubelet
9、检查组件状态
kubectl get cs
