Metrics Server 完整配置安装手册

Metrics Server 是 Kubernetes 集群的核心组件之一，用于聚合集群中节点和 Pod 的资源使用数据（如 CPU、内存），并通过 Metrics API 提供给 Horizontal Pod Autoscaler (HPA) 或 kubectl top 等工具使用。它轻量、高效，通常用于监控和自动扩缩容场景。本教程将教你如何完成Metrics Server 完整配置安装！

1. 删除现有部署（如有）

# 删除现有的 Metrics Server
kubectl delete -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml --ignore-not-found=true

# 或者强制删除所有相关资源
kubectl delete deployment metrics-server -n kube-system --ignore-not-found=true
kubectl delete service metrics-server -n kube-system --ignore-not-found=true
kubectl delete apiservice v1beta1.metrics.k8s.io --ignore-not-found=true
kubectl delete clusterrole system:aggregated-metrics-reader --ignore-not-found=true
kubectl delete clusterrolebinding metrics-server:system:auth-delegator --ignore-not-found=true
kubectl delete rolebinding metrics-server-auth-reader -n kube-system --ignore-not-found=true
kubectl delete clusterrolebinding metrics-server:system:metrics-server --ignore-not-found=true

2. 创建完整配置文件

创建 metrics-server.yaml 文件：

cat > metrics-server-fixed.yaml << 'EOF'
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:
  - nodes/metrics
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - pods
  - nodes
  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: metrics-server: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
        - --kubelet-insecure-tls
        image: registry.cn-hangzhou.aliyuncs.com/google_containers/metrics-server:v0.7.1
        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:
          allowPrivilegeEscalation: false
          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
EOF

3. 应用配置

# 应用完整配置
kubectl apply -f metrics-server.yaml

4. 等待部署完成

# 等待 Pod 启动
kubectl wait --for=condition=ready pod -l k8s-app=metrics-server -n kube-system --timeout=180s

# 或者实时观察部署状态
kubectl get pods -n kube-system -l k8s-app=metrics-server -w

5. 验证安装

# 检查 Pod 状态
kubectl get pods -n kube-system -l k8s-app=metrics-server

# 测试 Metrics Server 功能
kubectl top nodes

# 测试 Pod 指标
kubectl top pods -A

# 检查 API 服务状态
kubectl get apiservice v1beta1.metrics.k8s.io

6. 故障排除

如果出现镜像拉取问题

选项一：使用国内镜像源

# 修改镜像地址
sed -i 's|k8s.gcr.io/metrics-server/metrics-server:v0.7.1|registry.cn-hangzhou.aliyuncs.com/google_containers/metrics-server:v0.7.1|g' metrics-server.yaml

# 重新应用
kubectl apply -f metrics-server.yaml

选项二：使用官方最新版本

# 下载最新版本
curl -LO https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

# 应用
kubectl apply -f components.yaml

检查详细日志

# 查看 Pod 详细信息
kubectl describe pod -n kube-system -l k8s-app=metrics-server

# 查看日志
kubectl logs -n kube-system -l k8s-app=metrics-server

重启部署

# 重启 Metrics Server
kubectl rollout restart deployment/metrics-server -n kube-system

7. 配置说明

这个完整配置包含以下关键特性：

• 安全配置：使用非 root 用户运行，只读根文件系统
• 资源限制：CPU 100m，内存 200Mi
• 健康检查：就绪性和存活探针
• TLS 配置 ：跳过 Kubelet TLS 验证（--kubelet-insecure-tls）
• 高可用：滚动更新策略
• 优先级：系统集群关键优先级

8. 验证 HPA 功能

安装完成后，可以测试 HPA：

# 创建测试部署
kubectl create deployment hpa-test --image=nginx:alpine

# 创建 HPA
kubectl autoscale deployment hpa-test --cpu-percent=50 --min=1 --max=3

# 观察 HPA
kubectl get hpa hpa-test -w

这个完整配置应该能够解决大多数 Metrics Server 的安装问题。