틀린 문제 #6. Rolling Updates and Rollbacks

문제 1

Let us try that. Upgrade the application by setting the image on the deployment to kodekloud/webapp-color:v2

Do not delete and re-create the deployment. Only set the new image name for the existing deployment.

 

 

Deployment Name: frontend

 

Deployment Image: kodekloud/webapp-color:v2

---

# Deployment 확인

kubectl get deploy
NAME       READY   UP-TO-DATE   AVAILABLE   AGE
frontend   4/4     4            4           6m4s

 

# Deployment 상세 확인

kubectl describe deploy frontend
Name:                   frontend
Namespace:              default
CreationTimestamp:      Wed, 10 Dec 2025 00:52:11 +0000
Labels:                 <none>
Annotations:            deployment.kubernetes.io/revision: 1
Selector:               name=webapp
Replicas:               4 desired | 4 updated | 4 total | 4 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        20
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  name=webapp
  Containers:
   simple-webapp:
    Image:         kodekloud/webapp-color:v1
    Port:          8080/TCP
    Host Port:     0/TCP
    Environment:   <none>
    Mounts:        <none>
  Volumes:         <none>
  Node-Selectors:  <none>
  Tolerations:     <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   frontend-6b86c6b555 (4/4 replicas created)
Events:
  Type    Reason             Age    From                   Message
  ----    ------             ----   ----                   -------
  Normal  ScalingReplicaSet  6m12s  deployment-controller  Scaled up replica set frontend-6b86c6b555 from 0 to 4

 

# Rolling Update

kubectl set image deployment frontend simple-webapp=kodekloud/webapp-color:v2
deployment.apps/frontend image updated

 

문제 2

Change the deployment strategy to Recreate

Delete and re-create the deployment if necessary. Only update the strategy type for the existing deployment.

 

 

Deployment Name: frontend

 

Deployment Image: kodekloud/webapp-color:v2

 

Strategy: Recreate

---

# 이미 존재하는 deploy의 정보를 yaml 파일로 생성

kubectl get deploy frontend -o yaml > frontend.yaml

 

# frontend.yaml에서 Strategy를 Recreate로 변경

vi frontend.yaml
----------------
...
  strategy:
    type: Recreate
...
----------------

 

# 현재 존재하는 Deploy 삭제

kubectl delete deploy frontend
deployment.apps "frontend" deleted from default namespace

 

# 재배포

kubectl create -f frontend.yaml
deployment.apps/frontend created

 

문제 3

Upgrade the application by setting the image on the deployment to kodekloud/webapp-color:v3

Do not delete and re-create the deployment. Only set the new image name for the existing deployment.

 

 

Deployment Name: frontend

 

Deployment Image: kodekloud/webapp-color:v3

---

# Deploy 정보 확인

kubectl get deploy
NAME       READY   UP-TO-DATE   AVAILABLE   AGE
frontend   4/4     4            4           15m

kubectl describe deploy frontend
Name:                   frontend
Namespace:              default
CreationTimestamp:      Wed, 10 Dec 2025 00:52:11 +0000
Labels:                 <none>
Annotations:            deployment.kubernetes.io/revision: 2
Selector:               name=webapp
Replicas:               4 desired | 4 updated | 4 total | 4 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        20
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  name=webapp
  Containers:
   simple-webapp:
    Image:         kodekloud/webapp-color:v2
    Port:          8080/TCP
    Host Port:     0/TCP
    Environment:   <none>
    Mounts:        <none>
  Volumes:         <none>

 

# Rolling Update

kubectl set image deploy frontend simple-webapp=kodekloud/webapp-color:v3

 

# 확인

 watch -n 2 kubectl get deploy

 watch -n 2 kubectl get pods

 

watch 옵션은 리소스를 실시간으로 반복 조회

watch -n 2 : 2초마다 반복