[따배씨] 4. multi-container Pod 생성 / 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 

   : "hk8s" context 생성 

controlplane ~ ➜  k config get-clusters 
NAME
kubernetes

controlplane ~ ➜  k config get-contexts 
CURRENT   NAME                          CLUSTER      AUTHINFO           NAMESPACE
*         kubernetes-admin@kubernetes   kubernetes   kubernetes-admin   

controlplane ~ ➜ k config set-context hk8s --cluster kubernetes --user kubernetes-admin 
Context "hk8s" created.

controlplane ~ ➜  k config get-contexts 
CURRENT   NAME                          CLUSTER      AUTHINFO           NAMESPACE
          hk8s                          kubernetes   kubernetes-admin   
*         kubernetes-admin@kubernetes   kubernetes   kubernetes-admin   

controlplane ~ ➜  k config use-context hk8s
Switched to context "hk8s".

controlplane ~ ➜  k config get-contexts 
CURRENT   NAME                          CLUSTER      AUTHINFO           NAMESPACE
*         hk8s                          kubernetes   kubernetes-admin   
          kubernetes-admin@kubernetes   kubernetes   kubernetes-admin

 

---

 

 

[Question]

create pod

- 작업 클러스터 : hk8s
- Create a pod name lab004 with 3 containers running, nginx, redis, memcached

---

 

 

[Solve]

(1) pod 생성 옵션을 dry-run으로 확인 

controlplane ~ ➜  k run lab004 --image=nginx --dry-run=client -o yaml
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: lab004
  name: lab004
spec:
  containers:
  - image: nginx
    name: lab004
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

 

 

(2) yaml 파일에서 container 설정 추가 후 pod 생성

 

 

(3) 생성된 pod 확인 

: nginx, redis, memcached 컨테이너 생성 확인 

controlplane ~ ➜  k get pods lab004 -o yaml

---

 

 

[사용 커맨드 정리]

k run lab004 --image=nginx --dry-run=client -o yaml

k run lab004 --image=nginx --dry-run=client -o yaml > 4-multi.yaml

vi 4-multi.yaml

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: lab004
  name: lab004
spec:
  containers:
  - image: nginx
    name: nginx
  - image: redis
    name: redis
  - image: memcached
    name: memcached
status: {}

k apply -f 4-multi.yaml 

k get pods lab004 -o yaml