[ cka 준비 오답노트 ] Fix Kubelet

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Question 18 | Fix Kubelet

Q. There seems to be an issue with the kubelet not running on cluster3-worker1. Fix it and confirm that cluster has node cluster3-worker1 available in Ready state afterwards. You should be able to schedule a Pod on cluster3-worker1 afterwards.

Write the reason of the issue into /opt/course/18/reason.txt.

worker1 에서 kubelet 이 동작하지 않는 것 같다. 고쳐리.

키워드

• ps aux
• systemd
• journalctl -u kubelet

• service kubelet status

1. 상태를 확인한다.

➜ k get node
NAME               STATUS     ROLES    AGE   VERSION
cluster3-master1   Ready      master   27h   v1.23.1
cluster3-worker1   NotReady   <none>   26h   v1.23.1

2. worker1 내부에 들어가서 kubelet 을 확인한다.

➜ ssh cluster3-worker1

➜ root@cluster3-worker1:~# ps aux | grep kubelet
root     29294  0.0  0.2  14856  1016 pts/0    S+   11:30   0:00 grep --color=auto kubelet

3. kubectl 서비스 상태를 확인한다.

➜ root@cluster3-worker1:~#  service kubelet status
● kubelet.service - kubelet: The Kubernetes Node Agent
   Loaded: loaded (/lib/systemd/system/kubelet.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/system/kubelet.service.d
           └─10-kubeadm.conf
   Active: inactive (dead) since Sun 2019-12-08 11:30:06 UTC; 50min 52s ago
...

4. 뒤져있으니 시작을 해보자.

➜ service kubelet start

➜ service kubelet status
 kubelet.service - kubelet: The Kubernetes Node Agent (여기에 본인 설정 위치 나옴!)
   Loaded: loaded (/lib/systemd/system/kubelet.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/system/kubelet.service.d
           └─10-kubeadm.conf
   Active: activating (auto-restart) (Result: exit-code) since Thu 2020-04-30 22:03:10 UTC; 3s ago
     Docs: https://kubernetes.io/docs/home/
  Process: 5989 ExecStart=/usr/local/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS (code=exited, status=203/EXEC)
 Main PID: 5989 (code=exited, status=203/EXEC)

Apr 30 22:03:10 cluster3-worker1 systemd[5989]: kubelet.service: Failed at step EXEC spawning /usr/local/bin/kubelet: No such file or directory
Apr 30 22:03:10 cluster3-worker1 systemd[1]: kubelet.service: Main process exited, code=exited, status=203/EXEC
Apr 30 22:03:10 cluster3-worker1 systemd[1]: kubelet.service: Failed with result 'exit-code'.

/usr/local/bin/kubelet 이 없다고 뜬다.

5. kubelet 의 위치를 찾는다.

➜  whereis kubelet
➜ root@cluster3-worker1:~# whereis kubelet
kubelet: /usr/bin/kubelet

6. /etc/systemd/system/kubelet.service.d/10-kubeadm.conf 여기 가서 kubelet 위치 고친다.
7.  

systemctl daemon-reload && systemctl restart kubelet

systemctl status kubelet  # should now show running

8. 나와서 노드상태 확인한다. (시간이 지나면 반영됨)