K8S部署Metrics-Server服务

1.Metrics-Server介绍

在新版的K8S中，系统资源的采集均使用Metrics-Server服务，可以通过Metrics-Server服务采集节点和Pod的内存、磁盘、CPU和网络的使用率等信息。

说的具体点：新版K8S资源使用情况的度量（如容器的 CPU 和内存使用）可以通过 Metrics API 获取。

注意：

• Metrics API 只可以查询当前的度量数据，并不保存历史数据
• Metrics API URI 为 /apis/metrics.k8s.io/，在 k8s.io/metrics维护
• 必须部署 metrics-server 才能使用该 API，metrics-server 通过调用 Kubelet Summary API 获取数据

 

2.部署Metrics-Server服务

1）下载并解压Metrics-Server

wget https://github.com/kubernetes-sigs/metrics-server/archive/v0.3.6.tar.gz
tar -zxvf v0.3.6.tar.gz 

2）修改Metrics-Server配置文件

cd metrics-server-0.3.6/deploy/1.8+/
vim metrics-server-deployment.yaml

vim metrics-server-deployment.yaml文件原有的内容如下所示

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: metrics-server
  namespace: kube-system
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: metrics-server
  namespace: kube-system
  labels:
    k8s-app: metrics-server
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  template:
    metadata:
      name: metrics-server
      labels:
        k8s-app: metrics-server
    spec:
      serviceAccountName: metrics-server
      volumes:
      # mount in tmp so we can safely use from-scratch images and/or read-only containers
      - name: tmp-dir
        emptyDir: {}
      containers:
      - name: metrics-server
        image: k8s.gcr.io/metrics-server-amd64:v0.3.6
        imagePullPolicy: Always
        volumeMounts:
        - name: tmp-dir
          mountPath: /tmp

修改后的文件内容如下所示

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: metrics-server
  namespace: kube-system
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: metrics-server
  namespace: kube-system
  labels:
    k8s-app: metrics-server
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  template:
    metadata:
      name: metrics-server
      labels:
        k8s-app: metrics-server
    spec:
      serviceAccountName: metrics-server
      volumes:
      # mount in tmp so we can safely use from-scratch images and/or read-only containers
      - name: tmp-dir
        emptyDir: {}
      containers:
      - name: metrics-server
        # 修改image 和 imagePullPolicy
        image: mirrorgooglecontainers/metrics-server-amd64:v0.3.6
        imagePullPolicy: IfNotPresent
        # 新增command配置
        command:
        - /metrics-server
        - --kubelet-insecure-tls
        - --kubelet-preferred-address-types=InternalDNS,InternalIP,ExternalDNS,ExternalIP,Hostname
        volumeMounts:
        - name: tmp-dir
          mountPath: /tmp
        # 新增resources配置
        resources:
          limits:
            cpu: 300m
            memory: 200Mi
          requests:
            cpu: 200m
            memory: 100Mi

 3）安装Metrics-Server

kubectl apply -f metrics-server-0.3.6/deploy/1.8+/

 4）查看node信息

[root@k8s-master metrics-server]# kubectl top node
NAME         CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master   187m         4%     4765Mi          61%       
k8s-node1    109m         2%     3306Mi          42%       
k8s-node2    90m          2%     3112Mi          40% 

 可以看到，使用Metrics-Server收集到节点信息，说明Metrics-Server安装成功