不要设置 spec.replicas

**水平Pod自动扩容：**其他机器上多拉起几个Pod

**垂直Pod自动扩容：**当前机器多拉起几个Pod

1  Metrics Server部署

github地址： github

下载部署yml

国内镜像地址

metric-server.yaml

# 做如下修改
template:
    metadata:
      labels:
        k8s-app: metrics-server
    spec:
      containers:
      - args:
        - --cert-dir=/tmp
        - --secure-port=10250
        - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
        - --kubelet-use-node-status-port
        - --metric-resolution=15s
        - --kubelet-insecure-tls    #标志不需要证书验证
        # 镜像根据k8s的版本选择国内镜像
        image: swr.cn-north-4.myhuaweicloud.com/ddn-k8s/registry.k8s.io/metrics-server/metrics-server:v0.7.2

# 启动metricServer
kubectl apply -f metric-server.yaml
# 检测是否启动
kubectl get pods -A
kubectl top nodes

2 测试HPA

官网地址

创建php-apache.yaml

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: swr.cn-north-4.myhuaweicloud.com/ddn-k8s/k8s.gcr.io/hpa-example:latest
        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

创建hpa.yaml

apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  creationTimestamp: null
  name: php-apache
spec:
  maxReplicas: 10
  minReplicas: 1
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: php-apache
  targetCPUUtilizationPercentage: 50 ##所有Pod的平均CPU利用率为50%

监控hpa,pod

# 监控hpa
kubectl get hpa php-apache --watch
# 监控pod
kubectl get pod -l run=php-apache

批量执行请求，观察被监控的数据

# 每隔0.01秒发送一次请求
kubectl run -i --tty load-generator --rm --image=swr.cn-north-4.myhuaweicloud.com/ddn-k8s/docker.io/library/busybox:1.28 --restart=Never -- /bin/sh -c "while sleep 0.01; do wget -q -O- <http://php-apache>; done"