[따배씨] 12. Pod log 추출 / CKA 시험 문제 학습

이 포스팅은 아래의 유튜브 채널 "따배"를 따라서 학습한 내용입니다.  

 

 

[관련 이론]

---

 

 

[Precondition]

(1) 테스트 환경

(1.1) Rocky Linux Cluster 

: 직접 구성

[root@k8s-master ~]# k get nodes -o wide
NAME         STATUS   ROLES           AGE   VERSION   INTERNAL-IP     EXTERNAL-IP   OS-IMAGE                            KERNEL-VERSION                  CONTAINER-RUNTIME
k8s-master   Ready    control-plane   30d   v1.27.2   192.168.56.30   <none>        Rocky Linux 8.10 (Green Obsidian)   4.18.0-553.33.1.el8_10.x86_64   containerd://1.6.32
k8s-node1    Ready    <none>          30d   v1.27.2   192.168.56.31   <none>        Rocky Linux 8.8 (Green Obsidian)    4.18.0-477.10.1.el8_8.x86_64    containerd://1.6.21
k8s-node2    Ready    <none>          30d   v1.27.2   192.168.56.32   <none>        Rocky Linux 8.8 (Green Obsidian)    4.18.0-477.10.1.el8_8.x86_64    containerd://1.6.21
[root@k8s-master ~]#

 

(1.2) Ubuntu Cluster 

: kodekloud 테스트 환경 활용

controlplane ~ ➜  kubectl get nodes -o wide
NAME           STATUS   ROLES           AGE     VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION   CONTAINER-RUNTIME
controlplane   Ready    control-plane   9m6s    v1.31.0   192.6.94.6    <none>        Ubuntu 22.04.4 LTS   5.4.0-1106-gcp   containerd://1.6.26
node01         Ready    <none>          8m31s   v1.31.0   192.6.94.9    <none>        Ubuntu 22.04.4 LTS   5.4.0-1106-gcp   containerd://1.6.26

https://learn.kodekloud.com/user/courses/udemy-labs-certified-kubernetes-administrator-with-practice-tests

 

(2) 사전 필요 설정 

- "file not found"가 출력되는 pod 생성

controlplane ~ ➜  cat 12-pod.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: custom-app
spec:
  containers:
  - name: hello
    image: busybox:1.28
    command: ['sh', '-c', 'echo "file not found!"']

controlplane ~ ➜  k apply -f 12-pod.yaml 
pod/custom-app created

 

---

 

 

[Question#1]

Monitor the logs of pod custom-app and Extract log lines corresponding to error "file not found" 
Write them to /var/CKA2022/podlog.

---

 

 

[Solve]

(1) grep으로 원하는 로그 출력 후 파일로 생성 

controlplane ~ ➜  k logs pods/custom-app | grep -i "file not found"
file not found!

controlplane ~ ➜  k logs pods/custom-app | grep -i "file not found" > /var/CKA2022/podlog

controlplane ~ ➜  cat /var/CKA2022/podlog 
file not found!