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Configuration·Certified Kubernetes Administrator

Renewing Cluster Certificates

`kubeadm certs renew all` rewrites eleven certificates and tells you to restart four components. The apiserver's serving certificate reloads on its own - same container, ATTEMPT 0 - and the restart is for everything else.

Cluster Architecture and Configuration Guide 23 of 103 Advanced

Two nodes. The renewal and the restart happen on the control plane; the worker is there to prove the cluster survived.
Server NameIP AddressOSRolesCPURAMHDD
CKA3001192.168.0.185Ubuntu 26.04 LTSControl Plane Node2 Core4 GB50 GB
CKA3001-NODE01192.168.0.186Ubuntu 26.04 LTSWorker Node2 Core4 GB50 GB

Before you start

  1. Find out what expires and when

  2. Renew, and read the last line

  3. Restart the control plane by moving a file

Official sources