【k8s】metrics-server

环境

1. kubernetes 1.20.6
2. Spring Boot 2.5.0-RC1

目标

metrics-server 可以收集 k8s 集群的资源使用情况，并通过 dashboard 展示出来。

示例

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=443
            - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
            - --kubelet-use-node-status-port
            - --metric-resolution=15s
            - --kubelet-insecure-tls
          image: jiangbo920827/metrics-server:v0.5.0
          imagePullPolicy: IfNotPresent
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /livez
              port: https
              scheme: HTTPS
            periodSeconds: 10
          name: metrics-server
          ports:
            - containerPort: 443
              name: https
              protocol: TCP
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /readyz
              port: https
              scheme: HTTPS
            initialDelaySeconds: 20
            periodSeconds: 10
          securityContext:
            readOnlyRootFilesystem: true
            runAsNonRoot: true
            runAsUser: 1000
          volumeMounts:
            - mountPath: /tmp
              name: tmp-dir
      nodeSelector:
        kubernetes.io/os: linux
      priorityClassName: system-cluster-critical
      serviceAccountName: admin
      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

其中的 admin 服务账号，需要自己创建，如果之前的 rbac 示例执行过，默认就有。
如果没有，可以见附录。

查看资源

总结

介绍了 metric server 查看资源使用的图形界面。

附录

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-binding
subjects:
  - kind: ServiceAccount
    name: admin
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io