kubernetes(k8s)安装metrics-server实现资源使用情况监控方式详解

1. Metrics Server 与 kubenetes版本

Metrics Server    Metrics API group/version    Supported Kubernetes version

0.6x    metrics.k8s.io/v1beta1    *1.19+

0.5x    metrics.k8s.io/v1beta1    *1.8+

0.4x    metrics.k8s.io/v1beta1    *1.8+

0.3x    metrics.k8s.io/v1beta1    1.8-1.21

2. Metrics Server 下载方式

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

3. k8s集群安装部署metrics

本次安装的是metrics0.5.0版本

下载地址：https://github.com/kubernetes-sigs/metrics-server/releases

docker镜像地址：docker pull cnskylee/metrics-server:v0.5.0

4. 创建components-v0.5.0.yaml文件，并将下面的脚本copy到文件中

apiVersion: v1 kind: ServiceAccount metadata: labels: k8s-app: metrics-server name: metrics-server namespace: kube-system — apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: labels: k8s-app: metrics-server rbac.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.io resources: – pods – nodes verbs: – get – list – watch — apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: labels: k8s-app: metrics-server name: system:metrics-server rules: – apiGroups: – “” resources: – pods – nodes – nodes/stats – namespaces – configmaps verbs: – get – list – watch — apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: labels: k8s-app: metrics-server name: metrics-server-auth-reader namespace: kube-system roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: extension-apiserver-authentication-reader subjects: – kind: ServiceAccount name: metrics-server namespace: kube-system — apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: labels: k8s-app: metrics-server name: metrics-server:system:auth-delegator roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: system:auth-delegator subjects: – kind: ServiceAccount name: metrics-server namespace: kube-system — apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: labels: k8s-app: metrics-server name: system:metrics-server roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: system:metrics-server subjects: – kind: ServiceAccount name: metrics-server namespace: kube-system — apiVersion: v1 kind: Service metadata: labels: k8s-app: metrics-server name: metrics-server namespace: kube-system spec: ports: – name: https port: 443 protocol: TCP targetPort: https selector: k8s-app: metrics-server — apiVersion: apps/v1 kind: Deployment metadata: labels: k8s-app: metrics-server name: metrics-server namespace: kube-system spec: selector: matchLabels: k8s-app: metrics-server strategy: rollingUpdate: maxUnavailable: 0 template: metadata: labels: k8s-app: metrics-server spec: containers: – args: – –cert-dir=/tmp – –secure-port=4443 – –kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname – –kubelet-use-node-status-port – –metric-resolution=15s – –kubelet-insecure-tls image: registry.cn-shenzhen.aliyuncs.com/zengfengjin/metrics-server:v0.5.0 imagePullPolicy: IfNotPresent livenessProbe: failureThreshold: 3 httpGet: path: /livez port: https scheme: HTTPS periodSeconds: 10 name: metrics-server ports: – containerPort: 4443 name: https protocol: TCP readinessProbe: failureThreshold: 3 httpGet: path: /readyz port: https scheme: HTTPS initialDelaySeconds: 20 periodSeconds: 10 resources: requests: cpu: 100m memory: 200Mi securityContext: readOnlyRootFilesystem: true runAsNonRoot: true runAsUser: 1000 volumeMounts: – mountPath: /tmp name: tmp-dir nodeSelector: kubernetes.io/os: linux priorityClassName: system-cluster-critical serviceAccountName: metrics-server volumes: – emptyDir: {} name: tmp-dir — apiVersion: apiregistration.k8s.io/v1 kind: APIService metadata: labels: k8s-app: metrics-server name: v1beta1.metrics.k8s.io spec: group: metrics.k8s.io groupPriorityMinimum: 100 insecureSkipTLSVerify: true service: name: metrics-server namespace: kube-system version: v1beta1 versionPriority: 100

需要注意的是端口和镜像地址。

5. 执行部署

kubectl apply -f ./components-v0.5.0.yaml

4.查看metrics-server的pod运行状态

kubectl get pods -n kube-system| egrep NAME|metrics-server

5. 查看运行日志

# kubectl logs metrics-server-56874cd58b-b2gj9 -n kube-system I0418 09:49:44.461828 1 serving.go:341] Generated self-signed cert (/tmp/apiserver.crt, /tmp/apiserver.key) I0418 09:49:45.252957 1 requestheader_controller.go:169] Starting RequestHeaderAuthRequestController I0418 09:49:45.252972 1 shared_informer.go:240] Waiting for caches to sync for RequestHeaderAuthRequestController I0418 09:49:45.252994 1 configmap_cafile_content.go:202] Starting client-ca::kube-system::extension-apiserver-authentication::client-ca-file I0418 09:49:45.253002 1 shared_informer.go:240] Waiting for caches to sync for client-ca::kube-system::extension-apiserver-authentication::client-ca-file I0418 09:49:45.253142 1 configmap_cafile_content.go:202] Starting client-ca::kube-system::extension-apiserver-authentication::requestheader-client-ca-file I0418 09:49:45.253153 1 shared_informer.go:240] Waiting for caches to sync for client-ca::kube-system::extension-apiserver-authentication::requestheader-client-ca-file I0418 09:49:45.254091 1 secure_serving.go:197] Serving securely on [::]:4443 I0418 09:49:45.254139 1 tlsconfig.go:240] Starting DynamicServingCertificateController I0418 09:49:45.254342 1 dynamic_serving_content.go:130] Starting serving-cert::/tmp/apiserver.crt::/tmp/apiserver.key I0418 09:49:45.353087 1 shared_informer.go:247] Caches are synced for RequestHeaderAuthRequestController I0418 09:49:45.353087 1 shared_informer.go:247] Caches are synced for client-ca::kube-system::extension-apiserver-authentication::client-ca-file I0418 09:49:45.354631 1 shared_informer.go:247] Caches are synced for client-ca::kube-system::extension-apiserver-authentication::requestheader-client-ca-file

6.测试kubectl top命令的使用

# kubectl top pods -n kube-system NAME CPU(cores) MEMORY(bytes) coredns-58cc8c89f4-jdfc7 4m 12Mi coredns-58cc8c89f4-z8t26 5m 13Mi etcd-k8s-master 9m 281Mi kube-apiserver-k8s-master 22m 296Mi

查看节点资源：

# kubectl top nodes NAME CPU(cores) CPU% MEMORY(bytes) MEMORY% k8s-master 96m 2% 9330Mi 59% k8s-node83 66m 1% 5829Mi 37% k8s-node85 116m 2% 8555Mi 54%

查看默认空间pod资源：

# kubectl top pods NAME CPU(cores) MEMORY(bytes) nginx-6867cdf567-rprv9 0m 1Mi