Tag Archives: kubelet starts error

How to Solve kubelet starts error (k8s Cluster Restarted)

How to Solve kubelet starts error after k8s Cluster is Restarted

After the k8s cluster restarts, kubelet starts to solve the error

1 k8s version 1.23.0, docker CE version 20.10.14

2. An error is reported for the problem, and an error is reported for starting kubelet. The contents are as follows:

May 16 09:47:13 k8s-master kubelet: E0516 09:47:13.512956    7403 server.go:302] "Failed to run kubelet" err="failed to run Kubelet: misconfiguration: kubelet cgroup driver: \"systemd\" is different from docker cgroup driver: \"cgroupfs\""
May 16 09:47:13 k8s-master systemd: kubelet.service: main process exited, code=exited, status=1/FAILURE
May 16 09:47:13 k8s-master systemd: Unit kubelet.service entered failed state.
May 16 09:47:13 k8s-master systemd: kubelet.service failed

3 problem analysis: according to the error report, the reason should be that kubelet’s cgroups are inconsistent with docker

4. Solve the problem and modify the docker configuration

cat > /etc/docker/daemon.json <<EOF
{"exec-opts": ["native.cgroupdriver=systemd"]}
EOF

5. Restart docker to solve the problem

[root@k8s-master ~]# systemctl restart docker
[root@k8s-master ~]# systemctl restart kubelet
[root@k8s-master ~]# 
[root@k8s-master ~]# systemctl status  kubelet
● kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/usr/lib/systemd/system/kubelet.service; enabled; vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/kubelet.service.d
           └─10-kubeadm.conf
   Active: active (running) since Mon 2022-05-16 09:48:06 CST; 3s ago
     Docs: https://kubernetes.io/docs/
 Main PID: 8226 (kubelet)
    Tasks: 23
   Memory: 56.9M
   CGroup: /system.slice/kubelet.service
           ├─8226 /usr/bin/kubelet --bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --config...
           └─8745 /opt/cni/bin/calico