[CKA] Deployment & Pod Scale

1. Pod scale out

 

[문제]

* 작업 클러스터 : kubernetes-admin@kubernetes

- Expand the number of running Pods in "eshop-order" to 5.

 . namespace : devops

 . deployment : eshop-order

kubectl config use-context kubernetes-admin@kubernetes

kubectl get namspaces devops

kubectl get deployments.apps -n devops

kubectl scale deployment eshop-oerder --replicas=5 -n devops

kubectl get deploy -n devops

kubectl get pod -n devops

 

※ Scale 명령어는 아래 링크에서 참고

https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#scale

Kubectl Reference Docs

 

2. deployment 생성하고 Scaling 하기

 

[문제]

* 작업 클러스터 : kubernetes-admin@kubernetes

- Create a deployment as follows:

- TASK :

 . name : webserver

 . 2 replicas

 . label : app_env_stage=dev

 . container name: webserver

 . container images : nginx:1.14

- Scale Out Deployment.

 . Scale the deployment webserver to 3 pods

 

kubectl config use-context kubernetes-admin@kubernetes

kubectl create deployment webserver --image=nginx:1.14 --replicas=2 --dry-run=client -o yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: webserver
  name: webserver
spec:
  replicas: 2
  selector:
    matchLabels:
      app: webserver
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: webserver
    spec:
      containers:
      - image: nginx:1.14
        name: nginx
        resources: {}
status: {}

kubectl create deployment webserver --image=nginx:1.14 --replicas=2 --dry-run=client -o yaml > webserver.yaml

# 아래와 같이 수정

cat webserver.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: webserver
spec:
  replicas: 2
  selector:
    matchLabels:
      app_env_stage: dev
  template:
    metadata:
      labels:
        app_env_stage: dev
    spec:
      containers:
      - image: nginx:1.14
        name: webserver
	ports:
	- containerPort: 80

kubectl apply -f webserver.yaml
deployment.apps/webserver created

kubectl get deployments.apps
NAME        READY   UP-TO-DATE   AVAILABLE   AGE
webserver   2/2     2            2           42s

kubectl get deployments.apps -o wide
NAME        READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES       SELECTOR
webserver   2/2     2            2           51s   webserver    nginx:1.14   app_env_stage=dev

kubectl get pods 
NAME                        READY   STATUS    RESTARTS   AGE
webserver-c5b8f6c65-8ksqr   1/1     Running   0          68s
webserver-c5b8f6c65-p6mlb   1/1     Running   0          68s

kubectl scale deployment webserver --replicas=3
deployment.apps/webserver scaled

kubectl get pods --show-labels
NAME                        READY   STATUS    RESTARTS   AGE    LABELS
webserver-c5b8f6c65-8ksqr   1/1     Running   0          118s   app_env_stage=dev,pod-template-hash=c5b8f6c65
webserver-c5b8f6c65-9456q   1/1     Running   0          15s    app_env_stage=dev,pod-template-hash=c5b8f6c65
webserver-c5b8f6c65-p6mlb   1/1     Running   0          118s   app_env_stage=dev,pod-template-hash=c5b8f6c65

 

yaml 파일을 수정 후 apply 명령을 실행하다보면 아래와 같은 에러가 나타날때가 있다.

error: error parsing webserver.yaml: error converting YAML to JSON: yaml: line 18: found a tab character that violates indentation

 

:set list 를 통해 확인하면 tab으로 공백이 생겨서 그럴수 있다. 문제가 되는 공백을 제거한 다음 다시 apply 명령 실행시 정상적으로 된다.

 

 

[참고]

- 유투브 따배씨