本文章视频教程地址：https://www.bilibili.com/video/BV1TdxkedE1K

前言

笔者之前写过一篇文章关于在Kubernetes上安装 Prometheus 和 Grafana 监控去查看Kubernetes各个节点的资源占用率，文章地址：https://blog.csdn.net/m0_51510236/article/details/132601350

但是有一个更方便的方法，就是直接使用 kubectl 命令查看各个节点的资源使用情况。具体的命令如下：

kubectl top nodes

但默认的执行结果是：

原因是你没有安装 metrics-server，metrics-server 的github地址为：https://github.com/kubernetes-sigs/metrics-server。

安装 metrics-server

根据代码仓库的Releases列表显示，最新版本为 v0.7.2：

其中 v0.7.2 这个版本需要你的 Kubernetes 集群的版本为 1.19 或更高：

官方给出的安装命令为：

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

⚠️不要执行这个命令来安装 metrics-server，需要先将这个文件保存下来，并修改一些内容。可执行下面这行命令修改：

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

如果你是自己搭建的Kubernetes集群，你需要在 yaml 文件的 Deployment 当中添加这么一个执行参数：--kubelet-insecure-tls。如图加在约 137 行位置：

还有在 image 的配置中，默认镜像是 registry.k8s.io/metrics-server/metrics-server:v0.7.2 ，是在谷歌上拉取的，阿里云也有这个镜像，需要改成阿里云上的镜像： registry.aliyuncs.com/google_containers/metrics-server:v0.7.2，如图：

然后需要将 Deployment.spec.template.spec.hostNetwork 改为 false，如图：

修改好后的文件内容：

apiVersion: v1
kind: ServiceAccount
metadata:labels:k8s-app: metrics-servername: metrics-servernamespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:labels:k8s-app: metrics-serverrbac.authorization.k8s.io/aggregate-to-admin: "true"rbac.authorization.k8s.io/aggregate-to-edit: "true"rbac.authorization.k8s.io/aggregate-to-view: "true"name: system:aggregated-metrics-reader
rules:
- apiGroups:- metrics.k8s.ioresources:- pods- nodesverbs:- get- list- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:labels:k8s-app: metrics-servername: system:metrics-server
rules:
- apiGroups:- ""resources:- nodes/metricsverbs:- get
- apiGroups:- ""resources:- pods- nodesverbs:- get- list- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:labels:k8s-app: metrics-servername: metrics-server-auth-readernamespace: kube-system
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: extension-apiserver-authentication-reader
subjects:
- kind: ServiceAccountname: metrics-servernamespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:labels:k8s-app: metrics-servername: metrics-server:system:auth-delegator
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: system:auth-delegator
subjects:
- kind: ServiceAccountname: metrics-servernamespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:labels:k8s-app: metrics-servername: system:metrics-server
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: system:metrics-server
subjects:
- kind: ServiceAccountname: metrics-servernamespace: kube-system
---
apiVersion: v1
kind: Service
metadata:labels:k8s-app: metrics-servername: metrics-servernamespace: kube-system
spec:ports:- name: httpsport: 443protocol: TCPtargetPort: httpsselector:k8s-app: metrics-server
---
apiVersion: apps/v1
kind: Deployment
metadata:labels:k8s-app: metrics-servername: metrics-servernamespace: kube-system
spec:selector:matchLabels:k8s-app: metrics-serverstrategy:rollingUpdate:maxUnavailable: 0template:metadata:labels:k8s-app: metrics-serverspec:containers:- args:- --cert-dir=/tmp- --secure-port=10250- --kubelet-insecure-tls- --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname- --kubelet-use-node-status-port- --metric-resolution=15simage: registry.aliyuncs.com/google_containers/metrics-server:v0.7.2imagePullPolicy: IfNotPresentlivenessProbe:failureThreshold: 3httpGet:path: /livezport: httpsscheme: HTTPSperiodSeconds: 10name: metrics-serverports:- containerPort: 10250name: httpsprotocol: TCPreadinessProbe:failureThreshold: 3httpGet:path: /readyzport: httpsscheme: HTTPSinitialDelaySeconds: 20periodSeconds: 10resources:requests:cpu: 100mmemory: 200MisecurityContext:allowPrivilegeEscalation: falsecapabilities:drop:- ALLreadOnlyRootFilesystem: truerunAsNonRoot: truerunAsUser: 1000seccompProfile:type: RuntimeDefaultvolumeMounts:- mountPath: /tmpname: tmp-dirhostNetwork: falsenodeSelector:kubernetes.io/os: linuxpriorityClassName: system-cluster-criticalserviceAccountName: metrics-servervolumes:- emptyDir: {}name: tmp-dir
---
apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:labels:k8s-app: metrics-servername: v1beta1.metrics.k8s.io
spec:group: metrics.k8s.iogroupPriorityMinimum: 100insecureSkipTLSVerify: trueservice:name: metrics-servernamespace: kube-systemversion: v1beta1versionPriority: 100

然后执行该文件就可以安装成功了，同样我也修改好了这个文件并提交至github，可以啥也不改直接执行下面这样一行命令进行安装：

kubectl apply -f https://raw.githubusercontent.com/xiaohh-me/kubernetes-yaml/main/plugin/metrics-server/components-v0.7.2.yaml

执行完成如图：

可以执行这行命令查看是否安装成功：

kubectl get pod -n kube-system -o wide

成功运行如图：

使用 kubectl 查看 cpu 和内存占用率

接下来就可以执行这行命令查看 cpu 和内存占用率：

kubectl top nodes

执行结果如图：