A Kubernetes cluster provides multiple built-in certificates. When a corticated expires, you must renew it for the cluster to operate correctly.
Certificate | Validity |
CA | 10 years |
apiserver | 10 years |
kubelet-client | 10 years |
front-proxy | 10 years |
front-proxy | 10 years |
Execute the /etc/kubernetes/pki command.
Execute the openssl x509 -in certificate -noout –dates command to check the notBefore and notAfter fields for the validity period. For example, the validity period of the ca.crt certificate is 10 years.
Execute the kubeadm alpha certs renew command.