续订RCM Kubernetes证书

简介

本文档介绍在Cisco 5G RCM（冗余配置管理器）中续订Kubernetes证书的过程。

前提条件

如果它是RCM高可用性设置，则必须先在备用RCM上执行该过程，然后执行切换，并在新的备用RCM上运行该过程。如果没有RCM高可用性可用，UP冗余在RCM重新启动期间不可用，这是证书续订流程的一部分。

检查证书是否过期

要确保证书是否过期，请运行sudo kubeadm alpha certs check-expiration。

ubuntu@rcm:~$ sudo kubeadm alpha certs check-expiration
CERTIFICATE               EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
admin.conf                Oct 31, 2024 03:34 UTC   <invalid>       no
apiserver                 Oct 31, 2024 03:34 UTC   <invalid>       no
apiserver-etcd-client     Oct 31, 2024 03:34 UTC   <invalid>       no
apiserver-kubelet-client  Oct 31, 2024 03:34 UTC   <invalid>       no
controller-manager.conf   Oct 31, 2024 03:34 UTC   <invalid>       no
etcd-healthcheck-client   Oct 31, 2024 03:34 UTC   <invalid>       no
etcd-peer                 Oct 31, 2024 03:34 UTC   <invalid>       no
etcd-server               Oct 31, 2024 03:34 UTC   <invalid>       no
front-proxy-client        Oct 31, 2024 03:34 UTC   <invalid>       no
scheduler.conf            Oct 31, 2024 03:34 UTC   <invalid>       no

更新证书

运行sudo kubeadm alpha certs renew all以更新证书。

ubuntu@rcm:~$ sudo 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

如果证书已续订，请再次检查

运行sudo kubeadm alpha certs check-expiration以检查证书是否已续订。

ubuntu@rcm:~$ sudo kubeadm alpha certs check-expiration
CERTIFICATE               EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
admin.conf                Nov 01, 2025 03:34 UTC   364d            no
apiserver                 Nov 01, 2025 03:34 UTC   364d            no
apiserver-etcd-client     Nov 01, 2025 03:34 UTC   364d            no
apiserver-kubelet-client  Nov 01, 2025 03:34 UTC   364d            no
controller-manager.conf   Nov 01, 2025 03:34 UTC   364d            no
etcd-healthcheck-client   Nov 01, 2025 03:34 UTC   364d            no
etcd-peer                 Nov 01, 2025 03:34 UTC   364d            no
etcd-server               Nov 01, 2025 03:34 UTC   364d            no
front-proxy-client        Nov 01, 2025 03:34 UTC   364d            no
scheduler.conf            Nov 01, 2025 03:34 UTC   364d            no

修改kubelet.conf

在kubeadm版本1.17之前，需要手动修改kubelet.conf。将client-certificate-data和client-key-data替换为。

/etc/kubernetes/kubelet.conf

client-certificate:/var/lib/kubelet/pki/kubelet-client-current.pem
client-key: /var/lib/kubelet/pki/kubelet-client-current.pem

复制admin.conf

复制admin.conf以覆盖.kube/config。

sudo cp /etc/kubernetes/admin.conf ~/.kube/config

重新启动系统

sudo reboot

确保kubectl命令是否有效

重新启动后，确保kubectl命令运行正常。

ubuntu@rcm:~$ kubectl get node
NAME   STATUS   ROLES       AGE   VERSION
rcm    Ready    master,oam  16d   v1.15.12