[Day22] Certified Kubernetes Administrator (CKA) with Practice Tests

<Controle plane failure>

cluster 안의 node status 확인 

-> kubectl get nodes

cluster 안에 pod status 확인

-> kubectl get pods 

kube system name space에서 status 확인

-> kubectl get pods -n kube-system 

 

Controlplane services 확인

<Master node>

service kube-apiserver status

service kube-controller-manager status

service kube-scheduler status

 

<Worker node>

service kubelet status

service kube-proxy status

 

Service log 확인

kubectl logs kube-apiserver-master -n kube-system

api server's log 확인

sudo journalctl -u kube-apiserver

 

<Worker node failure>

kubectl get nodes

kubectl get node <node name>

-> status 확인 

top으로 cpu memory or disc specc 확인필요

kubectl top pods --sort-by =cpu or memory

or 

df -h

check kubelet status

service kubelet status

sudo journalctl -u kubelet

 

certificates 확인

openssl x509 -in /var/lib/kubelet/worker-1.crt -text

 

Troubleshooting issues related to kube-proxy

1. Check kube-proxy pod in the kube-system namespace is running.

2. Check kube-proxy logs.

3. Check configmap is correctly defined and the config file for running kube-proxy binary is correct.

4. kube-config is defined in the config map.

5. check kube-proxy is running inside the container

 

kubectl get pods -o=jsonpath='{.items[0].spec.container[0].image}'