Срок действия сертификатов, управляемых kubeadm, истекает через год после развертывания.
Если при получения данных из кластера например командой kubectl get pods -n kube-system
выдает:
Unable to connect to the server: tls: failed to verify certificate: x509: certificate has expired or is not yet valid: current time 2024-07-22T17:11:50+03:00 is after 2024-07-20T16:14:05Z
то проблема в сертификатах.
kubeadm certs check-expiration - проверьте текущую дату истечения срока действия сертификатов на каждой control-plane,master ноде.
в ответ получим:
[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'
[check-expiration] Error reading configuration from the Cluster. Falling back to default configuration
CERTIFICATE EXPIRES RESIDUAL TIME CERTIFICATE AUTHORITY EXTERNALLY MANAGED
admin.conf Jul 20, 2024 16:11 UTC <invalid> ca no
apiserver Jul 20, 2024 16:11 UTC <invalid> ca no
apiserver-etcd-client Jul 20, 2024 16:11 UTC <invalid> etcd-ca no
apiserver-kubelet-client Jul 20, 2024 16:11 UTC <invalid> ca no
controller-manager.conf Jul 20, 2024 16:12 UTC <invalid> ca no
etcd-healthcheck-client Jul 20, 2024 16:11 UTC <invalid> etcd-ca no
etcd-peer Jul 20, 2024 16:11 UTC <invalid> etcd-ca no
etcd-server Jul 20, 2024 16:11 UTC <invalid> etcd-ca no
front-proxy-client Jul 20, 2024 16:11 UTC <invalid> front-proxy-ca no
scheduler.conf Jul 20, 2024 16:12 UTC <invalid> ca no
CERTIFICATE AUTHORITY EXPIRES RESIDUAL TIME EXTERNALLY MANAGED
ca Jul 15, 2033 12:30 UTC 8y no
etcd-ca Jul 15, 2033 12:30 UTC 8y no
front-proxy-ca Jul 15, 2033 12:30 UTC 8y no
Чтобы обновить сертификаты, используйте команду kubeadm certs renew all на каждом control-plane,master узле вашего кластера Kubernetes.
При выполнении kubeadm certs renew all мы получим:
[renew] Reading configuration from the cluster...
[renew] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[renew] Error reading configuration from the Cluster. Falling back to default configuration
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 healthcheck 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
Done renewing certificates. You must restart the kube-apiserver, kube-controller-manager, kube-scheduler and etcd, so that they can use the new certificates.
Еще раз проверьте дату истечения срока действия с помощью команды kubeadm certs check-expiration на каждом основном узле вашего кластера.
Ответ будет:
CERTIFICATE EXPIRES RESIDUAL TIME CERTIFICATE AUTHORITY EXTERNALLY MANAGED
admin.conf Jul 22, 2025 14:49 UTC 364d ca no
apiserver Jul 22, 2025 14:49 UTC 364d ca no
apiserver-etcd-client Jul 22, 2025 14:49 UTC 364d etcd-ca no
apiserver-kubelet-client Jul 22, 2025 14:49 UTC 364d ca no
controller-manager.conf Jul 22, 2025 14:49 UTC 364d ca no
etcd-healthcheck-client Jul 22, 2025 14:49 UTC 364d etcd-ca no
etcd-peer Jul 22, 2025 14:49 UTC 364d etcd-ca no
etcd-server Jul 22, 2025 14:49 UTC 364d etcd-ca no
front-proxy-client Jul 22, 2025 14:49 UTC 364d front-proxy-ca no
scheduler.conf Jul 22, 2025 14:49 UTC 364d ca no
CERTIFICATE AUTHORITY EXPIRES RESIDUAL TIME EXTERNALLY MANAGED
ca Jul 15, 2033 12:30 UTC 8y no
etcd-ca Jul 15, 2033 12:30 UTC 8y no
front-proxy-ca Jul 15, 2033 12:30 UTC 8y no
Перезапустите следующие поды с любого из основных узлов, чтобы использовать новые сертификаты
kubectl delete pod -n kube-system -l component=kube-apiserver
kubectl delete pod -n kube-system -l component=kube-scheduler
kubectl delete pod -n kube-system -l component=kube-controller-manager
kubectl delete pod -n kube-system -l component=etcd
Отобразить перезапущенные pods
kubectl get pods -n kube-system
Просмотреть логи:
kubectl logs <pod_name> -n kube-system