쿠버네티스 기초 YAML 파일 작성 하기

YAML 파일은 object를 만들거나 Pod's replicas, deployment 서비스 등 모든곳에서 사용합니다.

쿠버네티스에서 yaml파일을 사용하기위해서 기본적으로 필요한 것이 있다(apiVersion, kind, metadata, spec)

apiVersion:
kind:
metadata:

spec:

apiVersion : 쿠버네티스의 api 버전을 이야기 한다.

kind : 무엇을 만들것인지 를 정함(POD, Service, ReplicaSet, Deployment)

metadata: 리소스의 이름, Label 등을 지정 한다.

spec: 생성하고자 하는 리소스들의 종류나 타입들에 따라서 다르다.

아래에서는 테스트로 싱글 pod에 2개의 Container를 만들어 보겠습니다.

#1pod_2container.yml
apiVersion: v1
kind: Pod #string
metadata: 
  name: 1pod-2container
  labels: # dictionary
   app: ubuntu-nginx
spec:
 containers: 
  - name: nginx-container 
    image: nginx
  - image: ubuntu
    name: ubuntu
    command: ["/bin/sh"]
    args: ["-c", "while true; do echo hello; sleep 10;done"] 
    # Docker 에서는 command에 인자값을 줄때 Cmd를 사용했지만 Kubernetes에서는 arg를 사용한다.

yaml 파일을 다 작성 했으면 kuberctl create를 사용하여 pod을 생성해보겠습니다.

kubectl create -f 1pod-2container.yml

kubectl get pods 을 통해 만들어진 Pod을 확인할수 있고 kubectl describe pod myapp-pod로 자세한 설명을 볼수 있다.

KDS-2:yaml kimdaesung$ kubectl get pods
NAME              READY   STATUS              RESTARTS   AGE
1pod-2container   0/2     ContainerCreating   0          8s



KDS-2:yaml kimdaesung$ kubectl describe pod 1pod-2container 
Name:         1pod-2container
Namespace:    default
Priority:     0
Node:         m01/192.168.99.100
Start Time:   Sun, 22 Mar 2020 17:54:46 +0900
Labels:       name=ubuntu-nginx
Annotations:  <none>
Status:       Running
IP:           172.17.0.4
IPs:
  IP:  172.17.0.4
Containers:
  ubuntu:
    Container ID:  docker://5598b16f73ad58705520efd472c36d491f6658523440b5f5478a8dc2a3ab9242
    Image:         ubuntu
    Image ID:      docker-pullable://ubuntu@sha256:bec5a2727be7fff3d308193cfde3491f8fba1a2ba392b7546b43a051853a341d
    Port:          <none>
    Host Port:     <none>
    Command:
      /bin/sh
    Args:
      -c
      while true; do echo hello; sleep 10;done
    State:          Running
      Started:      Sun, 22 Mar 2020 17:54:55 +0900
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-rs2h4 (ro)
  nginx-container:
    Container ID:   docker://f6a18a3c9b29caf925d30b605ef8590309af712a22a7a18b87bcf5979aa012aa
    Image:          nginx
    Image ID:       docker-pullable://nginx@sha256:2539d4344dd18e1df02be842ffc435f8e1f699cfc55516e2cf2cb16b7a9aea0b
    Port:           <none>
    Host Port:      <none>
    State:          Running
      Started:      Sun, 22 Mar 2020 17:55:06 +0900
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-rs2h4 (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-rs2h4:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-rs2h4
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  61s   default-scheduler  Successfully assigned default/1pod-2container to m01
  Normal  Pulling    61s   kubelet, m01       Pulling image "ubuntu"
  Normal  Pulled     52s   kubelet, m01       Successfully pulled image "ubuntu"
  Normal  Created    52s   kubelet, m01       Created container ubuntu
  Normal  Started    52s   kubelet, m01       Started container ubuntu
  Normal  Pulling    52s   kubelet, m01       Pulling image "nginx"
  Normal  Pulled     41s   kubelet, m01       Successfully pulled image "nginx"
  Normal  Created    41s   kubelet, m01       Created container nginx-container
  Normal  Started    41s   kubelet, m01       Started container nginx-container