Content Comparison

file위치는 master node의 아래에 위치한다.

root@cp-k8s:~/2024_k8s/edu# pwd
/root/2024_k8s/edu
root@cp-k8s:~/2024_k8s/edu# ls
10 12 13 15 3 5 6 7 8 9 Readme.md

kubectl run test-nginx --image=nginx:1.19

apiVersion: v1
kind: Pod
metadata:
  name: test-nginx
spec:
  containers:
  - name: test-nginx
    image: nginx:1.19
    ports:
    - containerPort: 80

# yaml 파일 적용
kubectl apply -f [yaml file]

# pod 조회
kubectl get pod -n [namespace]
=> namespace를 지정하지 않으면 default namespace에 있는 pod를 조회합니다.

# 모든 Namespace의 pod 조회
kubectl get pod -A

# pod 수정
kubectl edit pod [pod name]

# pod 삭제 
kubectl delete pod [pod name]
kubectl delete -f [yaml 파일]

[root@m-k8s 0907]# cat nginx.yaml
apiVersion: v1
kind: Pod
metadata:
  name: test-nginx2
spec:
  containers:
  - name: test-nginx2
    image: nginx:1.19    ===> nginx:latest로 변경 
    ports:
    - containerPort: 80
[root@m-k8s 0907]# kubectl edit pod/test-nginx2
pod/test-nginx2 edited
[root@m-k8s 0907]# kubectl describe pod/test-nginx2
Events:
  Type    Reason   Age                From     Message
  ----    ------   ----               ----     -------
  Normal  Created  18s (x2 over 64m)  kubelet  Created container test-nginx2
  Normal  Killing  18s                kubelet  Container test-nginx2 definition changed, will be restarted
  Normal  Pulled   18s                kubelet  Container image "nginx:latest" already present on machine
  Normal  Started  17s (x2 over 64m)  kubelet  Started container test-nginx2

[root@m-k8s 0907]# kubectl edit pod test-nginx
A copy of your changes has been stored to "/tmp/kubectl-edit-1281676954.yaml"
error: At least one of apiVersion, kind and name was changed
[root@m-k8s 0907]# kubectl get pods
NAME          READY   STATUS   kubelet RESTARTS   ContainerAGE
test-nginx2nginx definition changed, will be1/1 restarted   Normal Running Pulled  0 18s           11m
test-nginx2   1/1 kubelet  Container image "nginx:latest"Running already present on0 machine   Normal  Started  17s (x2 over 64m)  kubelet  Started container test-nginx2

[root@m-k8s 0907]# kubectl get pod test-nginx2 -o yaml > test-nginx4.yaml
[root@m-k8s 0907]# vi test-nginx4.yaml
# name change from test-nginx2 to test-nginx4
[root@m-k8s 0907]# kubectl applycreate -f /tmp/kubectl-edit-1281676954test-nginx4.yaml
pod/test-nginx3nginx4 created

[root@m-k8s 0907]# kubectl get pods
NAME          READY   STATUS    RESTARTS      AGE
test-nginx    1/1     Running   0   STATUS    RESTARTS      AGE165m
test-nginxnginx2    1/1     Running   01 (99m ago)   163m
test-nginx3   1/1    84m test-nginx2Running   1/10     Running   1 (18m ago)   83m153m
test-nginx3nginx4   1/1     Running   0             72m

yaml 파일은 아래 4가지의 형태를 가지며 해당 오브젝트내 값을 선언하여 사용

apiVersion : # kubectl api-versions 명령어로 사용가능한 apiversion을 확인
kind : # kubectl api-resources : 명령어로 해당 api에서 사용가능한 리소스 확인
metadata :
spec :

kubectl explain으로 하위 정보를 모두 확인할수 있다.

root@cp-k8s:~/2024_k8s/edu/5# kubectl explain pod.metadata.name

bash-completion 를 이용하여 kubectl도 자동완성 기능을 사용 할 수 있습니다

[root@m-k8s 0907]# apt install bash-completion -y
kubectl completion bash >> ~/.bashrc 등록후 재 접속 합니다 exit

[root@m-k8s 0907]# kubectl ap <tab> 누르면 자동완성

통상적으로 kubernetes는 k로 alias 주어서 수행

[root@m-k8s 0907]# which k
alias k='kubectl'
/bin/kubectl

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: nginx-rs
  labels:
    app: nginx-rs
    tier: nginx-rs
spec:
  # modify replicas according to your case
  replicas: 3
  selector:
    matchLabels:
      tier: nginx-rs
  template:
    metadata:
      labels:
        tier: nginx-rs
    spec:
      containers:
      - name: nginx-rs
        image: nginx

# kubectl get pod
NAME             READY   STATUS    RESTARTS   AGE
nginx-rs-hxd29   1/1     Running   0          79s
nginx-rs-nh7q4   1/1     Running   0          79s
nginx-rs-zr4fl   1/1     Running   0          79s
=> replica로 생성된 3개의 pod를 확인할 수 있습니다.

# pod 삭제
kubectl delete pod nginx-rs-hxd29

# kubectl get pod
NAME             READY   STATUS    RESTARTS   AGE
nginx-rs-nh7q4   1/1     Running   0          2m4s
nginx-rs-zbqlc   1/1     Running   0          79s8s
nginx-rs-nh7q4zr4fl   1/1     Running   0          2m4s
=> yaml  79s파일에 선언된 개수만큼 유지하기 위해 한 개의 pod 새로 생성됩니다.

# kubectl scale replicaset --replicas 2 nginx-rs-zr4fl
# kubectl get pods
NAME              1/1     Running   0          79s => replica로 생성된 3개의 pod를 확인할READY 수 있습니다. STATUS # pod 삭제 kubectlRESTARTS delete pod nginx-rs-hxd29  # kubectl get pod
NAMEAGE
nginx-rs-2d9f6              READY   STATUS    RESTARTS   AGE nginx-rs-nh7q4   1/1     Running   0          2m4s    2m23s
nginx-rs-zbqlcpk7ll      1/1     Running   0          8s nginx-rs-zr4fl   1/1     Running   0          2m4s
=> yaml 파일에 선언된 개수만큼 유지하기2m23s
위해
한# 개의kubectl pod 새로 생성됩니다.delete rs/nginx-rs

# k apply -f 03-configmap.yaml

root@cp-k8s:~/2024_k8s/edu/5# echo "prod-user" > prod-user.txt
root@cp-k8s:~/2024_k8s/edu/5# echo "prod-pass" > prod-pass.txt

kubectl apply -f 06-secret-deployment.yaml

root@k8s-master01:~/kb# kubectl exec -it secretapp-69d4797f86-7r95g -- bash

root@secretapp-69d4797f86-7r95g:/# env | grep SECRET
SECRET_USERNAME=prod-user
SECRET_PASSWORD=prod-pass

root@cp-k8s:~/2024_k8s/edu/5# kubectl delete deploy/configmap-test
deployment.apps  key: password