[쿠버네티스] annotation (어노테이션)

annotation (어노테이션)

정의

• Label과 동일하게 key-value를 통해 리소스의 특성을 기록
• Kubernetes 에게 특정 정보 전달할 용도로 사용
• 예를 들어 Deployment의 rolling update 정보 기록

  annotations:
    kubernetes.io/change-cause: version 1.15​​

• 관리를 위해 필요한 정보를 기록할 용도로 사용
• 릴리즈, 로깅, 모니터링에 필요한 정보들을 기록

  annotations:
    builder: "홍길동"
    buildDate: "20211203"
    imageRegistry: https://hub.docker.com/​​

생성

root@master:~# cat > annotation.yaml
apiVersion: v1
kind: Pod
metadata:
  name: pod-annotation
  annotations:
    builder: "Hong Gil Dong"
    buildDate: "20211203"
    imageRegistry: https://hub.docker.com
spec:
  containers:
  - name: nginx
    image: nginx:1.14		
    ports:
    - containerPort: 80
root@master:~# kubectl create -f annotation.yaml 
pod/pod-annotation created

 

조회

describe로 조회해보면 Annotations 부분에 설정한 정보가 잘 기록되어있는 것을 볼 수 있다.

root@master:~# kubectl get pods -o wide
NAME             READY   STATUS    RESTARTS   AGE   IP          NODE                NOMINATED NODE   READINESS GATES
pod-annotation   1/1     Running   0          4s    10.36.0.1   node1.example.com   <none>           <none>
root@master:~# kubectl describe pod pod-annotation 
Name:         pod-annotation
Namespace:    default
Priority:     0
Node:         node1.example.com/10.100.0.101
Start Time:   Thu, 02 Dec 2021 22:08:58 +0900
Labels:       <none>
Annotations:  buildDate: 20211203
              builder: Hong Gil Dong
              imageRegistry: https://hub.docker.com
Status:       Running
IP:           10.36.0.1
IPs:
  IP:  10.36.0.1
Containers:
  nginx:
    Container ID:   docker://edaea5b3f2a90b7348c97bda459b771b62be02b9ed92afd16194d6adde986cea
    Image:          nginx:1.14
    Image ID:       docker-pullable://nginx@sha256:f7988fb6c02e0ce69257d9bd9cf37ae20a60f1df7563c3a2a6abe24160306b8d
    Port:           80/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Thu, 02 Dec 2021 22:09:01 +0900
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-v7s6p (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  kube-api-access-v7s6p:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       <nil>
    DownwardAPI:             true
QoS Class:                   BestEffort
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  16s   default-scheduler  Successfully assigned default/pod-annotation to node1.example.com
  Normal  Pulled     6s    kubelet            Container image "nginx:1.14" already present on machine
  Normal  Created    6s    kubelet            Created container nginx
  Normal  Started    5s    kubelet            Started container nginx