Horizontal Pod Autoscaler

vi my-nginx.yml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: my-nginx
  name: my-nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      run: my-nginx
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
      - image: nginx
        name: my-nginx
        resources:
          # requests ⇒ pod를 만들때 최소 리소스 설정
          requests:
            # 250m ⇒ 0.25 CPU
            cpu: 250m
            memory: 64Mi
          # 최대 리소스 설정
          limits:
            cpu: 500m
            memory: 128Mi

vi hpa.yml

apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  name: my-nginx-hpa
  namespace: default
spec:
  scaleTargetRef:
    kind: Deployment
    apiVersion: apps/v1
    name: my-nginx
  # 최대 replicas 수
  maxReplicas: 4
  minReplicas: 1
  metrics:
  - type: Resource
    resource:
      # 대상 cpu 가 20%를 초과하면 확장한다.
      name: cpu
      targetAverageUtilization: 20

kubectl apply -f my-nginx.yml -f hpa.yml

#해당 pod shell 접근
apt update
apt install vim

vi shell.sh

#!/bin/bash
START=0
END=1000000000000000000
	while [ $START -le $END ]
    	do
    	START=`expr $START + 1`
done

chmod 777 shell.sh
./shell.sh

#다른 콘솔창에서 확인한다.
kubectl get pods
kubectl top pod
kubectl get hpa