【Kubernetes】Horizonal Pod Autoscaleを設定する

試すためのDeploymentを作成

apiVersion: apps/v1
kind: Deployment
metadata:
  name: php-apache
spec:
  selector:
    matchLabels:
      run: php-apache
  template:
    metadata:
      labels:
        run: php-apache
    spec:
      containers:
      - name: php-apache
        image: registry.k8s.io/hpa-example
        ports:
        - containerPort: 80
        resources:
          limits:
            cpu: 500m
          requests:
            cpu: 200m
---
apiVersion: v1
kind: Service
metadata:
  name: php-apache
  labels:
    run: php-apache
spec:
  ports:
  - port: 80
  selector:
    run: php-apache

適用

kubectl apply -f hpa.yaml

オートスケールを設定

kubectl autoscale deployment php-apache --cpu-percent=50 --min=1 --max=10

kubectl get hpa
NAME         REFERENCE               TARGETS         MINPODS   MAXPODS   REPLICAS   AGE
php-apache   Deployment/php-apache   /50%   1         10        0          7s

負荷コマンドを実行する

kubectl run -i --tty load-generator --rm --image=busybox --restart=Never -- /bin/sh -c "while sleep 0.01; do wget -q -O- http://php-apache; done"

Pod数を確認すると、増えていることがわかる。

kubectl get pod -A -o wide | grep php
default          php-apache-598b474864-8tdfd                              1/1     Running   0               7m45s   10.1.128.253   microk8s   <none>           <none>
default          php-apache-598b474864-wzkt4                              1/1     Running   0               5m55s   10.1.128.206   microk8s   <none>           <none>
default          php-apache-598b474864-szmf4                              1/1     Running   0               5m55s   10.1.128.199   microk8s   <none>           <none>
default          php-apache-598b474864-4mq97                              1/1     Running   0               5m55s   10.1.128.202   microk8s   <none>           <none>
default          php-apache-598b474864-c2pfr                              1/1     Running   0               5m40s   10.1.128.200   microk8s   <none>           <none>
default          php-apache-598b474864-hg9bw                              1/1     Running   0               5m10s   10.1.128.215   microk8s   <none>           <none>
default          php-apache-598b474864-qnjfz                              1/1     Running   0               4m55s   10.1.128.217   microk8s   <none>           <none>
default          php-apache-598b474864-h8cvh                              1/1     Running   0               4m55s   10.1.128.218   microk8s   <none>           <none>