k8s HPA

1、centos7安装k8s集群
2、k8s HPA 实战

安装metrics-server支持HPA

https://github.com/kubernetes-sigs/metrics-server

Configuration

Depending on your cluster setup, you may also need to change flags passed to the Metrics Server container. Most useful flags:

• --kubelet-preferred-address-types - The priority of node address types used when determining an address for connecting to a particular node (default [Hostname,InternalDNS,InternalIP,ExternalDNS,ExternalIP])
• --kubelet-insecure-tls - Do not verify the CA of serving certificates presented by Kubelets. For testing purposes only.
• --requestheader-client-ca-file - Specify a root certificate bundle for verifying client certificates on incoming requests.

下载components.yaml

https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

修改components.yaml（- --kubelet-insecure-tls 不验证证书 image使用aliyun镜像）

kubectl apply -f ./components.yaml

获取cpu memory指标

Kubectl top nodes

示例

是一个简单的tomcatdemo，对数据进行查询 http://192.168.164.11:30001/demo/

myweb

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myweb
  labels:
    app: myweb
spec:
  selector:
    matchLabels:
      app: myweb
  replicas: 2
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: myweb
    spec:
      containers:
        - name: myweb
          image: kubeguide/tomcat-app:v1
          ports:
            - containerPort: 8080
          resources:
            requests:
              cpu: 20m
            limits:
              cpu: 200m
          env:
            - name: MYSQL_SERVICE_HOST
              value: 10.1.128.91
            - name: MYSQL_SERVICE_PORT
              value: "3306"

myweb-service

apiVersion: v1
kind: Service
metadata:
  name: myweb
spec:
  type: NodePort
  ports:
    - port: 8080
      nodePort: 30001
  selector:
    app: myweb

mysql

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
        - name: mysql
          image: mysql:5.5
          ports:
            - name: container3306
              containerPort: 3306
          env:
            - name: MYSQL_ROOT_PASSWORD
              value: '123456'

mysql-service

apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  ports:
    - port: 3306
  selector:
    app: mysql

HorizontalPodAutoscaler

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: myweb-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: myweb
  minReplicas: 1
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 50

或者使用命令

kubectl autoscale deployment myweb --cpu-percent=50 --min=2 --max=10

压测