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    RESTARTS   AGE
test-nginx    1/1     Running   0          11m
test-nginx2   1/1     Running   0          10m
[root@m-k8s 0907]# kubectl apply -f /tmp/kubectl-edit-1281676954.yaml
pod/test-nginx3 created

[root@m-k8s 0907]# kubectl get pods
NAME          READY   STATUS    RESTARTS      AGE
test-nginx    1/1     Running   0          79s
nginx-rs-zr4fl   84m
test-nginx2   1/1     Running   01 (18m ago)   83m
test-nginx3   1/1 79s => replica로 생성된 3개의Running pod를 확인할 수0 있습니다.  # pod 삭제 kubectl delete     pod nginx-rs-hxd29

 72m

[root@m-k8s 0907]# kubectl get pod NAMEtest-nginx2 -o yaml > test-nginx4.yaml
[root@m-k8s 0907]# vi test-nginx4.yaml
# name change from READYtest-nginx2 to  STATUS    RESTARTS   AGE
nginx-rs-nh7q4   1/1test-nginx4
[root@m-k8s 0907]# kubectl create -f test-nginx4.yaml
pod/test-nginx4 created
[root@m-k8s 0907]# kubectl get pods
NAME          RunningREADY   0STATUS    RESTARTS      2m4sAGE
nginx-rs-zbqlctest-nginx    1/1     Running   0          8s
nginx-rs-zr4fl   165m
test-nginx2   1/1     Running   01 (99m ago)   163m
test-nginx3   1/1 2m4s => yaml 파일에 선언된Running 개수만큼 유지하기 위해0 한 개의 pod  새로 생성됩니다.

# pod 정보 자세히 보기

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:
       5 tier: nginx-rs
    5spec:
      containers:
    5  - name: nginx-rs
      kubernetes.io/os=linux   25h
nodelocaldns   5    image: nginx

# kubectl get pod
NAME     5        READY   STATUS 5   RESTARTS   AGE
5nginx-rs-hxd29   1/1     Running   0 5         79s
nginx-rs-nh7q4   kubernetes.io/os=linux   22h

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19
         ports:
 TYPE     DATA   AGE prod-user-secret   Opaque   2      4s


root@k8s-master01:~/kb# kubectl get secrets prod-user-secret -o yaml
apiVersion: v1
data:
  prod-pass.txt: cHJvZC1wYXNzCg==
  prod-user.txt: cHJvZC11c2VyCg==
kind: Secret
metadata:
  creationTimestamp: "2023-03-13T02:35:54Z"
  name: prod-user-secret
  namespace: default
  resourceVersion: "1226226"
  uid: 41a2cb2d-97f2-41bc-824f-c0c2783ec678
type: Opaque


*원래 값 확인방
root@k8s-master01:~/kb# echo cHJvZC11c2VyCg== | base64 --decode
prod-user

root@k8s-master01:~# kubectl -n kube-system get ds
NAME           DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR            AGE
calico-node    5         5         5       5            5           kubernetes.io/os=linux   25h
kube-proxy     5         5         5       TYPE5     DATA   AGE prod-user   Opaque5   2      5s  
root@k8s-master01:~/kb# kubectl get secrets prod-user -o yaml
apiVersion: v1
data:
  password: cHJvZC1wYXNz
  username: cHJvZC11c2Vy
kind: Secret
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"v1","data":{"password":"cHJvZC1wYXNz","username":"cHJvZC11c2Vy"},"kind":"Secret","metadata":{"annotations":{},"name":"prod-user","namespace":"default"},"type":"Opaque"}
  creationTimestamp: "2023-03-13T02:49:45Z"
  name: prod-user
  namespace: default
  resourceVersion: "1228228"
  uid: a5eff12c-2329-4697-92f7-f252a4f724ba
type: Opaque

apiVersion: v1
kind: ConfigMap
metadata:
  name: secretappprod-account
  labelsnamespace: default
data:
  appID: secretappprod-user
spec:   replicas: 1
  selector:
    matchLabels:
      app: secretapp
  templatePASSWORD: prod-pass
  LOG_LEVEL: info

# k apply -f 03-configmap.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: configmap-test
  labels:
    metadataapp: prod
spec:
    labelsreplicas: 1
  selector:
    matchLabels:
      app: prod
  template:
    metadata: secretapp
      labels:
        app: prod
    spec:
      containers:
      - name: testapp
        image: nginx:1.19
        ports:
        - containerPort: 8080
        env:
          - name: SECRETLOG_USERNAMELEVEL
            valueFrom:
              secretKeyRefconfigMapKeyRef:
                 name: prod-useraccount
                 key: username
   LOG_LEVEL

root@k8s-master01:~/kb# kubectl get pod
NAME       - name: SECRET_PASSWORD             valueFrom:        READY   STATUS    secretKeyRef:RESTARTS   AGE
configmap-test-779ff45747-f4969   1/1     Running   0  name: prod-user           80s

    key: password

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

root@k8s-master01:~/kb# cat prod-user.txt
prod-user
root@k8s-master01:~/kb# cat prod-pass.txt
prod-pass


root@k8s-master01:~/kb# kubectl create secret generic prod-user-secret --from-file=./prod-user.txt --from-file=./prod-pass.txt
secret/prod-user-secret created


root@k8s-master01:~/kb# kubectl get secrets
NAME            Retain   TYPE     DATA   AvailableAGE
prod-user-secret   Opaque   2      4s


root@k8s-master01:~/kb# kubectl get secrets prod-user-secret -o yaml
apiVersion: v1
data:
  prod-pass.txt: cHJvZC1wYXNzCg==
     15s

root@k8s-master01:~/kb# echo -n "prod-user" | base64
cHJvZC11c2Vy
root@k8s-master01:~/kb# echo -n "prod-pass" | base64
cHJvZC1wYXNz

apiVersion: v1
kind: Secret
metadata:
  name: prod-user
type: Opaque
data:
  username: cHJvZC11c2Vy
  password: cHJvZC1wYXNz

root@k8s-master01:~/kb# kubectl apply -f 05-secret.yaml

root@k8s-master01:~/kb# kubectl get secrets
NAME        TYPE     DATA   AGE
prod-user   Opaque   2      5s


root@k8s-master01:~/kb# kubectl get secrets prod-user -o yaml
apiVersion: v1
data:
  password: cHJvZC1wYXNz
  username: cHJvZC11c2Vy
kind: Secret
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"v1","data":{"password":"cHJvZC1wYXNz","username":"cHJvZC11c2Vy"},"kind":"Secret","metadata":{"annotations":{},"name":"prod-user","namespace":"default"},"type":"Opaque"}
  creationTimestamp: "2023-03-13T02:49:45Z"
  name: prod-user
  namespace: default
  resourceVersion: "1228228"
  uid: a5eff12c-2329-4697-92f7-f252a4f724ba
type: Opaque

apiVersion: apps/v1
kind: Deployment
metadata:
  name: secretapp
  labels:
    app: secretapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: secretapp
  template:
    metadata:
      labels:
        app: secretapp
    spec:
      containers:
      - name: testapp
        image: nginx:1.19
        ports:
        - namecontainerPort: test-pv8080
    volumes:   - nameenv:
test-pv     persistentVolumeClaim:     -  claimNamename: test-pvcSECRET_USERNAME
 # 옵션 - volumeMounts.mountPath: 볼륨 마운트할 컨테이너 안의 경로를 작성합니다. - volumes:.persistentVolumeClaim: 컨테이너에서 사용할 PV의 이름을 가져오고, PV와 연결되어 있으며 요청을 보낼 PVC를 지정합니다.

# 적용하기
kubectl apply -f test-nginx2.yaml

# 확인해보기
# 외부에서 확인
# kubectl describe pod test-nginx2 | grep -A1 MountsvalueFrom:
              secretKeyRef:
                name: prod-user
          Mounts:       /test/volume from test-pv (rw)

# 컨테이너 내부에서 확인
kubectl exec -it test-nginx2 -- bash
root@test-nginx2:/# df -Th | grep volume
/dev/vda1      xfskey: username
          - name: SECRET_PASSWORD
            valueFrom:
          50G  3.7G  secretKeyRef:
47G   8% /test/volume => 지정한 경로에 볼륨이 마운트된 것을 확인할 수 있습니다.  # 컨테이너 내부에서 test용 파일 생성
root@test-nginx2:/# touch /test/volume/test.txt

# PV 생성 시 설정한 노드의 경로에서도 확인이 가능합니다.
[root@worker-node ~]# ls -al /test/volume/
total 0
drwxr-xr-x 2 root root 22 Mar 10 06:22 .
drwxr-xr-x 3 root root 20 Mar 10 06:18 ..
-rw-r--r-- 1 root root  0 Mar 10 06:22 test.txtname: prod-user
                key: password

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 "configmap-test" deleted
root@cp-k8s:~/2024_k8s/edu/5# kubectl delete deploy/secretapp
deployment.apps "secretapp" deleted
root@cp-k8s:~/2024_k8s/edu/6# kubectl delete deploy/nginx-deployment