Kube-Prometheus监控MySQL（二）

一、概述

本文介绍如何使用 Kube-Prometheus 监控 MySQL 数据库。通过部署 MySQL Exporter，将 MySQL 的性能指标暴露给 Prometheus 进行采集和监控。

核心组件：

MySQL Exporter：用于暴露 MySQL 指标的 Exporter（镜像版本：v0.14.0）
ServiceMonitor：Prometheus Operator 的 CRD，用于服务发现和指标采集配置

二、部署 MySQL Exporter

2.1 创建 Deployment

通过 Deployment 部署 MySQL Exporter，需要配置数据库连接信息。

apiVersion: apps/v1
kind: Deployment
metadata:
  #设置唯一名称，建议添加数据库实例ip
  name:  mysql-exporter-172.16.1.77 
  namespace: monitoring
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: mysql-exporter
    app.kubernetes.io/part-of: kube-prometheus
    app.kubernetes.io/version: v0.14.0
spec:
  selector:
    matchLabels:
      app.kubernetes.io/component: exporter
      app.kubernetes.io/name: mysql-exporter
      app.kubernetes.io/part-of: kube-prometheus
  replicas: 1
  template:
    metadata:
      labels:
        app.kubernetes.io/component: exporter
        app.kubernetes.io/name: mysql-exporter
        app.kubernetes.io/part-of: kube-prometheus
        app.kubernetes.io/version: v0.14.0
    spec:
      containers:
        - name: mysql-exporter
          image: prom/mysqld-exporter:v0.14.0
          env:
            - name: DATA_SOURCE_NAME
              # 格式：用户名:密码@(数据库地址:端口)/
              # 示例：root:password@(mysql-service.share-components:3306)/
              value: "root:password@(mysql-service.share-components:3306)/"
          resources:
            requests:
              cpu: 20m
              memory: 20Mi
            limits:
              cpu: 100m
              memory: 30Mi
          ports:
            - containerPort: 9104
              name: http
          volumeMounts:
            - name: localtime
              mountPath: /etc/localtime
      volumes:
        - name: localtime
          hostPath:
            path: /usr/share/zoneinfo/Asia/Shanghai
      restartPolicy: Always

配置说明：

DATA_SOURCE_NAME：MySQL 连接串，需替换为实际的用户名、密码和地址
resources：资源限制，根据实际监控规模调整
volumeMounts：挂载宿主机时区文件，确保容器时区正确

2.2 创建 Service

为 MySQL Exporter 创建 Service，暴露监控端口。

apiVersion: v1
kind: Service
metadata:
  name: mysql-exporter
  namespace: monitoring
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: mysql-exporter
    app.kubernetes.io/part-of: kube-prometheus
    app.kubernetes.io/version: v0.14.0
    platform: mos
spec:
  selector:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: mysql-exporter
    app.kubernetes.io/part-of: kube-prometheus
  type: ClusterIP
  ports:
    - name: http
      port: 9104
      targetPort: http

配置说明：

port: 9104：MySQL Exporter 默认暴露端口
platform: mos：自定义标签，用于区分不同环境

2.3 创建 ServiceMonitor

ServiceMonitor 用于告诉 Prometheus 如何采集 MySQL Exporter 的指标。

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  labels:
    app.kubernetes.io/component: exporter
    app.kubernetes.io/name: mysql-exporter
    app.kubernetes.io/part-of: kube-prometheus
    app.kubernetes.io/version: v0.14.0
  name: mysql-exporter
  namespace: monitoring
spec:
  endpoints:
    - interval: 15s
      port: http
      relabelings:
        - action: replace
          regex: (.*)
          replacement: $1
          sourceLabels:
            - __meta_kubernetes_pod_node_name
          targetLabel: instance
      scheme: http
  jobLabel: app.kubernetes.io/name
  targetLabels: [platform]
  selector:
    matchLabels:
      app.kubernetes.io/component: exporter
      app.kubernetes.io/name: mysql-exporter
      app.kubernetes.io/part-of: kube-prometheus

配置说明：

interval: 15s：每 15 秒采集一次指标
relabelings：指标重写规则，将 Pod 节点名作为 instance 标签值
targetLabels：将 Service 的 platform 标签添加到采集的指标中

三、验证部署

# 查看 Deployment 状态
kubectl get deployment mysql-exporter-172.16.1.77 -n monitoring

# 查看 Pod 日志
kubectl logs -f <pod-name> -n monitoring

# 访问 Exporter 指标接口
kubectl port-forward svc/mysql-exporter 9104:9104 -n monitoring
curl http://localhost:9104/metrics