k8s 实现自动伸缩扩容

创建pod副本

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  namespace: nginx
  labels:
    app: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      imagePullSecrets:
      - name: login
      volumes:
      - name: master-nginx-vhost
        hostPath:
          path: /public/nginx/vhost
          type: DirectoryOrCreate
      - name: master-nginx-ssl
        hostPath:
          path: /public/nginx/ssl
      - name: nginx-config-volume
        configMap:
          name: nginx-config    
      containers:
      - name: nginx
        image: private.yd-data.com/zjj/tengine:latest
        imagePullPolicy: Always
        ports:
        - containerPort: 443
        volumeMounts:
        - name: master-nginx-vhost
          mountPath: /etc/nginx/vhost
        - name: master-nginx-ssl
          mountPath: /etc/nginx/ssl
        - name: nginx-config-volume
          mountPath: /etc/nginx/nginx.conf
          subPath: nginx.conf
        resources:
          requests:
            cpu: "1000m"  # 最少可获得1000 毫核= 1核
          limits:
            cpu: "2000m"  # 最多可获得2000 毫核= 2核
        securityContext:
          capabilities:
            add:
              - SYS_RESOURCE  # 添加 SYS_RESOURCE 能力，允许设置资源限制
---
apiVersion: v1                  # service api版本 
kind: Service                   # 使用service 模块
metadata:                           # 元数据
  name: nginx   # 新建自定义service 模块的名字
  namespace: nginx
spec:                    # service 信息
  type: NodePort                # 使用Nodeport协议，对外提供开放端口 
  ports:                        # 端口信息
    - port: 443                # service 的端口
      targetPort: 443  # 容器tomcat的端口
      nodePort: 443   # 自定义对外开发的端口
  selector:                #  选择标签器
    app: nginx            # app nginx 此名字要匹配deployment 的app: nginx

创建rbac授权

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: hpa-metrics-reader
  namespace: nginx
rules:
- apiGroups:
  - metrics.k8s.io
  resources:
  - pods
  - nodes
  verbs:
  - get
  - list
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: hpa-metrics-reader-binding
  namespace: nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: hpa-metrics-reader
subjects:
- kind: ServiceAccount
  name: default  # 假设使用默认的 ServiceAccount
  namespace: nginx

最后创建hpa

apiVersion: autoscaling/v2beta2
#apiVersion: autoscaling/v2  #Kubernetes 1.23 版本以上支持
kind: HorizontalPodAutoscaler
metadata:
  name: nginx-hpa
  namespace: nginx
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: nginx-deployment
  minReplicas: 2
  maxReplicas: 5
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 50
#Kubernetes 1.23版本以上支持一下配置
#behavior:
#  scaleDown:
#    stabilizationWindowSeconds: 300  # 缩容冷却时间，单位为秒
#    policies:
#    - type: Percent #表示按照百分比来缩容，value: 10 意味着每次最多减少 10% 的 Pod 副本数量
#      value: 100
#      periodSeconds: 15 #表示检查周期为 15 秒，即 HPA 每 15 秒检查一次是否需要进行缩容操作
#    - type: Pods  #表示按照固定数量的 Pod 来缩容，value: 1 表示每次至少减少 1 个 Pod
#      value: 1
#      periodSeconds: 15

查看hpa状态

kubectl get hpa -n nginx

压力测试pod检查是否能自动伸缩

kubectl exec -it -n nginx nginx-deployment-7f45f46888-prd6b -- stress-ng --cpu 1 --timeout 300s

kubectl top pod -n nginx