Prometheus实战教程:k8s平台-Redis监控案例

发布于:2025-05-11 ⋅ 阅读:(23) ⋅ 点赞:(0)

以下是 Prometheus 自动发现 Redis 实例的完整 YAML 文件示例,适用于生产环境。该配置包括:

  1. Redis 部署:运行 Redis 实例。
  2. Redis Exporter:用于暴露 Redis 指标。
  3. Prometheus 自动发现:通过 Kubernetes 服务发现自动抓取 Redis 实例。

1. Redis 部署文件 (redis-deployment.yaml)

apiVersion: apps/v1
kind: Deployment
metadata:
  name: redis
  labels:
    app: redis
spec:
  replicas: 3
  selector:
    matchLabels:
      app: redis
  template:
    metadata:
      labels:
        app: redis
      annotations:
        prometheus.io/scrape: "true"  # 允许 Prometheus 抓取
        prometheus.io/port: "9121"    # Redis Exporter 暴露的端口
    spec:
      containers:
      - name: redis
        image: harbor.fq.com/public/redis:7.4.1  # 使用官方 Redis 镜像
        ports:
        - containerPort: 6379  # Redis 默认端口
      - name: redis-exporter
        image: harbor.fq.com/prometheus/redis-exporter:1.67.0  # Redis Exporter 镜像
        ports:
        - containerPort: 9121  # Redis Exporter 默认端口
        env:
        - name: REDIS_ADDR
          value: "redis://localhost:6379"  # Redis 连接地址
---
apiVersion: v1
kind: Service
metadata:
  name: redis-service
  labels:
    app: redis
  annotations:
    prometheus.io/scrape: "true"  # 允许 Prometheus 抓取
    prometheus.io/port: "9121"    # Redis Exporter 暴露的端口
spec:
  selector:
    app: redis
  ports:
  - protocol: TCP
    name: redis
    port: 6379
    targetPort: 6379
  - protocol: TCP
    name: redis-exporter
    port: 9121
    targetPort: 9121
  type: ClusterIP

2. Prometheus 自动发现配置 (prometheus.yml)

Prometheus 自动发现 Redis 实例并指定监控 Redis Exporter 端口(9121)的完整配置。该配置确保 Prometheus 能够自动发现 Redis 实例,并抓取 Redis Exporter 暴露的指标

scrape_configs:
   - job_name: 'redis'
        kubernetes_sd_configs:
          - role: endpoints  # 从 Kubernetes Endpoints 发现服务
        relabel_configs:
          # 只抓取带有 `prometheus.io/scrape: "true"` 注解的服务
          - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
            action: keep
            regex: true

          # 替换目标地址为服务的 IP 和指定端口(9121)
          - source_labels: [__meta_kubernetes_endpoint_address_target_kind, __meta_kubernetes_endpoint_address_target_name]
            action: keep
            regex: Pod;(.*redis.*)  # 仅抓取名称包含 "redis" 的 Pod
          - source_labels: [__meta_kubernetes_pod_ip]
            action: replace
            target_label: __address__
            replacement: $1:9121  # 指定 Redis Exporter 的端口为 9121

          # 添加 Kubernetes 服务的 app 标签
          - source_labels: [__meta_kubernetes_service_label_app]
            action: replace
            target_label: app

          # 添加 Kubernetes 命名空间标签
          - source_labels: [__meta_kubernetes_namespace]
            action: replace
            target_label: namespace

          # 添加 Kubernetes 服务名称标签
          - source_labels: [__meta_kubernetes_service_name]
            action: replace
            target_label: service

          # 添加 Kubernetes Pod 名称标签
          - source_labels: [__meta_kubernetes_pod_name]
            action: replace
            target_label: pod

          # 添加 Kubernetes 节点名称标签
          - source_labels: [__meta_kubernetes_pod_node_name]
            action: replace
            target_label: node

          # 添加实例标签(用于区分不同的 Redis 实例)
          - source_labels: [__meta_kubernetes_pod_ip]
            action: replace
            target_label: instance

配置说明

  1. 自动发现

    • 使用 kubernetes_sd_configs 从 Kubernetes 的 Endpoints 自动发现服务。

    • 通过 __meta_kubernetes_service_annotation_prometheus_io_scrape 注解,确保只抓取明确标记为需要监控的服务。

  2. 指定端口

    • 通过 replacement: $1:9121 将目标地址替换为 Redis Exporter 的端口 9121

    • 使用 __meta_kubernetes_pod_ip 获取 Redis Pod 的 IP 地址,并拼接端口 9121

  3. 标签优化

    • 添加 Kubernetes 元数据标签(如 appnamespaceservicepod 等),便于后续查询和告警。

    • 使用 instance 标签区分不同的 Redis 实例。


3. 部署步骤

  1. redis-deployment.yaml 保存到 Kubernetes 集群。

  2. 部署 Redis 和 Redis Exporter:

    kubectl apply -f redis-deployment.yaml
  3. 更新 Prometheus 配置文件(prometheus.yml),添加 Redis 的自动发现配置。

  4. 重启 Prometheus 以加载新配置。


4. 验证

  1. 访问 Prometheus Web UI(http://<prometheus-server>:9090),查看 Targets 页面,确认 Redis 目标已被发现。
  2. 查询 Prometheus 中的 Redis 指标(如 redis_upredis_commands_processed_total)。

5. 生产环境建议

  • 高可用性:部署多个 Redis 实例,并使用 Redis Sentinel 或 Redis Cluster 实现高可用。
  • 监控告警:设置 Redis 关键指标的告警规则(如内存使用率、连接数等)。
  • 资源限制:为 Redis 和 Redis Exporter 设置资源限制(CPU 和内存)。
  • 日志管理:收集 Redis 和 Redis Exporter 的日志,便于排查问题。

6. 示例告警规则 (redis-alerts.yml)

6.1创建alert-rules-configmap文件

cat prometheus-alert-rules-redis-configmap.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-alert-rules-redis
  namespace: monitoring
  labels:
    app: prometheus
    role: alert-rules
data:
  redis.rules: |-
    groups:
    - name: redis_alerts
      rules:
      - alert: RedisDown
        expr: redis_up == 0
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "Redis is down"
          description: "Redis instance {{ $labels.instance }} is down."

      - alert: HighRedisMemoryUsage
        expr: redis_memory_used_bytes / redis_memory_max_bytes > 0.8
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High memory usage on Redis"
          description: "Redis memory usage is above 80% on {{ $labels.instance }}."

      - alert: HighRedisConnections
        expr: redis_connected_clients > 1000
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High number of Redis connections"
          description: "Redis instance {{ $labels.instance }} has more than 1000 connections."

注释版

# ========================
# Kubernetes ConfigMap 配置
# ========================
apiVersion: v1  # 必需字段,指定 Kubernetes API 版本
kind: ConfigMap  # 资源类型为配置映射
metadata:
  name: prometheus-alert-rules-redis  # 资源名称(需符合DNS命名规范)
  namespace: monitoring  # 必须与Prometheus部署的命名空间一致
  labels:  # 标签用于资源筛选
    app: prometheus  # 标识属于Prometheus组件
    role: alert-rules  # 标识用途为告警规则

# ========================
# 告警规则数据部分(核心配置)
# ========================
data:
  # 注意:文件名后缀必须是 .rules 或 .yaml 才能被Prometheus自动加载
  redis.rules: |-  # 关键符号说明: 
                   # "|" 保留换行符,"-" 表示删除文件末尾的换行符
                   # 缩进必须使用2个空格(不能使用Tab)

    # Prometheus告警规则语法开始
    groups:  # 告警规则组定义(至少需要1个组)
    - name: redis_alerts  # 组名称(显示在告警信息中)
      rules:  # 规则列表开始

      # ---- 规则1:Redis实例宕机检测 ----
      - alert: RedisDown  # 告警名称(需唯一)
        expr: redis_up == 0  # PromQL表达式:
                             # - redis_up 是指标名称
                             # - ==0 表示实例不可用
        for: 1m  # 持续时长(防止瞬时抖动)
        labels:  # 标签(可用于告警路由)
          severity: critical  # 严重级别(通常分 critical/warning/info)
        annotations:  # 告警详情模板
          summary: "Redis服务宕机 (实例: {{ $labels.instance }})"
          description: |- 
            Redis实例 {{ $labels.instance }} 已持续宕机1分钟
            所属集群: {{ $labels.cluster }}
            当前状态值: {{ $value }}

      # ---- 规则2:内存使用率告警 ----
      - alert: HighRedisMemoryUsage
        expr: >  # 多行表达式写法
          redis_memory_used_bytes / 
          redis_memory_max_bytes > 0.8  # 内存使用率超过80%
        for: 5m  # 持续5分钟触发(适合资源类告警)
        labels:
          severity: warning
          component: database  # 自定义标签(可用于筛选)
        annotations:
          description: |-
            内存使用率 {{ printf "%.2f" (mul $value 100) }}% 
            实例: {{ $labels.instance }}
            建议: 1. 检查是否有大Key 2. 考虑扩容

      # ---- 规则3:连接数告警 ----
      - alert: HighRedisConnections
        expr: redis_connected_clients > 1000
        for: 5m
        labels:
          severity: warning
        annotations:
          description: |-
            当前连接数: {{ $value }}
            最大允许连接数: {{ query "redis_config_maxclients{instance='{{ $labels.instance }}'}" | first | value }}
            # 使用query函数动态获取redis的maxclients配置值
6.2修改prometheus-deployment.yaml文件,添加volumeMounts,t volumes
 volumeMounts:
        - name: prometheus-config
          mountPath: /etc/prometheus  # 配置文件挂载点
        - name: prometheus-storage
          mountPath: /prometheus  # TSDB 数据存储路径
        - name: prometheus-alert-rules-redis
          mountPath: /etc/prometheus/rules/redis
      volumes:
      - name: prometheus-config
        configMap:
          name: prometheus-config  # 从 ConfigMap 挂载 Prometheus 配置
      - name: prometheus-storage
        emptyDir: {}  # 测试环境可使用空目录
      - name: prometheus-alert-rules-redis
        configMap:
          name: prometheus-alert-rules-redis

完整实例

apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus
  namespace: monitoring  # 指定命名空间
  labels:
    app: prometheus
spec:
  replicas: 1  # 生产环境通常建议 1 个实例,使用远程存储提高可用性
  selector:
    matchLabels:
      app: prometheus
  template:
    metadata:
      labels:
        app: prometheus
    spec:
      serviceAccountName: prometheus  # 关联 ServiceAccount,便于 RBAC 访问
      containers:
      - name: prometheus
        image: harbor.fq.com/prometheus/prometheus:v3.1.0  # 使用私有仓库镜像
        args:
        - --config.file=/etc/prometheus/prometheus.yml  # 指定 Prometheus 配置文件
        - --storage.tsdb.path=/prometheus  # 存储 TSDB 数据的位置
        - --web.console.templates=/etc/prometheus/consoles
        - --web.console.libraries=/etc/prometheus/console_libraries
        ports:
        - containerPort: 9090  # Prometheus Web 界面端口
        resources:  # 限制 CPU 和内存,防止资源耗尽
          requests:
            cpu: "500m"
            memory: "1Gi"
          limits:
            cpu: "1"
            memory: "2Gi"
        volumeMounts:
        - name: prometheus-config
          mountPath: /etc/prometheus  # 配置文件挂载点
        - name: prometheus-storage
          mountPath: /prometheus  # TSDB 数据存储路径
        - name: prometheus-alert-rules
          mountPath: /etc/prometheus/rules
        - name: file-sd
          mountPath: /apps/prometheus/file-sd.yaml
        - name: prometheus-alert-rules-redis
          mountPath: /etc/prometheus/rules/redis
      volumes:
      - name: prometheus-config
        configMap:
          name: prometheus-config  # 从 ConfigMap 挂载 Prometheus 配置
      - name: prometheus-storage
        emptyDir: {}  # 测试环境可使用空目录
      - name: prometheus-alert-rules
        configMap:
          name: prometheus-alert-rules
      - name: file-sd
        hostPath:
          path: /root/file-sd.yaml
          type: File
      - name: prometheus-alert-rules-redis
        configMap:
          name: prometheus-alert-rules-redis
---
apiVersion: v1
kind: Service
metadata:
  name: prometheus
  namespace: monitoring
  labels:
    app: prometheus
spec:
  type: NodePort  # 在生产环境中建议使用 LoadBalancer 或 Ingress
  ports:
  - port: 9090
    targetPort: 9090
    nodePort: 30090  # 通过 NodePort 访问 Web 界面
  selector:
    app: prometheus
6.3修改prometheus-configmap.yaml文件,添加rule_files文件路径
    rule_files:
      - /etc/prometheus/rules/*.rules
      - /etc/prometheus/rules/redis/*.rules

完整实例

cat prometheus-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: monitoring
data:
  prometheus.yml: |
    global:
      scrape_interval: 15s
      evaluation_interval: 15s
    rule_files:
      - /etc/prometheus/rules/*.rules
      - /etc/prometheus/rules/redis/*.rules
    scrape_configs:
      - job_name: 'prometheus'
        static_configs:
          - targets: ['localhost:9090']

      - job_name: 'kubernetes-nodes'
        kubernetes_sd_configs:
          - role: node
        relabel_configs:
          - source_labels: [__address__]
            regex: '(.*):10250'
            replacement: '${1}:9100'
            target_label: __address__

      - job_name: 'kubernetes-pods'
        kubernetes_sd_configs:
          - role: pod
        relabel_configs:
          - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
            action: keep
            regex: true
          - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
            action: replace
            target_label: __metrics_path__
            regex: (.+)
          - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
            action: replace
            regex: ([^:]+)(?::\d+)?;(\d+)
            replacement: $1:$2
            target_label: __address__
      - job_name: 'kube-state-metrics'
        kubernetes_sd_configs:
          - role: endpoints
            namespaces:
              names:
                - kube-system
                - default
                - monitoring
        relabel_configs:
          - source_labels: [__meta_kubernetes_service_label_app_kubernetes_io_name]
            action: keep
            regex: kube-state-metrics
          - source_labels: [__meta_kubernetes_endpoint_port_name]
            action: keep
            regex: http-metrics
        metrics_path: /metrics
        scheme: http
      - job_name: 'file_sd_node'
        file_sd_configs:
        - files:
          - /apps/prometheus/file-sd.yaml
          refresh_interval: 1m
      - job_name: 'kubernetes-apiservers'
        kubernetes_sd_configs:
        - role: endpoints
          namespaces:
            names: ["default"]
        scheme: https
        tls_config:
          insecure_skip_verify: true  # 生产环境应配置CA证书
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        relabel_configs:
        - source_labels: [__meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
          action: keep
          regex: default;kubernetes;https
      - job_name: 'kube-controller-manager'
        kubernetes_sd_configs:
        - role: endpoints
          namespaces:
            names: ["kube-system"]
        scheme: https
        tls_config:
          insecure_skip_verify: true
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        relabel_configs:
        - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
          action: keep
          regex: kube-controller-manager;https-metrics

      - job_name: 'kube-scheduler'
        kubernetes_sd_configs:
        - role: endpoints
          namespaces:
            names: ["kube-system"]
        scheme: https
        tls_config:
          insecure_skip_verify: true
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        relabel_configs:
        - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
          action: keep
          regex: kube-scheduler;https-metrics
      - job_name: 'etcd'
        static_configs:
        - targets: ['10.255.209.2:2379', '10.255.209.5:2379', '10.255.209.27:2379']  # 替换为实际etcd地址
        scheme: https
        tls_config:
          insecure_skip_verify: true
          #cert_file: /etc/prometheus/secrets/etcd-client.crt
          #key_file: /etc/prometheus/secrets/etcd-client.key
      - job_name: 'kubelet'
        scheme: https
        tls_config:
          insecure_skip_verify: true
        bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
        kubernetes_sd_configs:
        - role: node
        relabel_configs:
        - action: labelmap
          regex: __meta_kubernetes_node_label_(.+)
        - target_label: __address__
          replacement: kubernetes.default.svc:443
        - source_labels: [__meta_kubernetes_node_name]
          regex: (.+)
          target_label: __metrics_path__
          replacement: /api/v1/nodes/${1}/proxy/metrics
      - job_name: 'kube-proxy'
        kubernetes_sd_configs:
        - role: endpoints
          namespaces:
            names: ["kube-system"]
        scheme: http
        relabel_configs:
        - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
          action: keep
          regex: kube-proxy;metrics
      - job_name: 'kube-proxy1'
        kubernetes_sd_configs:
        - role: endpoints
          namespaces:
            names: ["kube-system"]
        scheme: http
        relabel_configs:
        - source_labels: [__meta_kubernetes_pod_name]  # 直接匹配 Pod
          action: keep
          regex: kube-proxy-.*
        - source_labels: [__address__]
          action: replace
          regex: ([^:]+)(?::\d+)?
          replacement: ${1}:10249  # 强制使用 10249 端口
          target_label: __address__
      - job_name: 'redis'
        kubernetes_sd_configs:
          - role: endpoints  # 从 Kubernetes Endpoints 发现服务
        relabel_configs:
          # 只抓取带有 `prometheus.io/scrape: "true"` 注解的服务
          - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
            action: keep
            regex: true

          # 替换目标地址为服务的 IP 和指定端口(9121)
          - source_labels: [__meta_kubernetes_endpoint_address_target_kind, __meta_kubernetes_endpoint_address_target_name]
            action: keep
            regex: Pod;(.*redis.*)  # 仅抓取名称包含 "redis" 的 Pod
          - source_labels: [__meta_kubernetes_pod_ip]
            action: replace
            target_label: __address__
            replacement: $1:9121  # 指定 Redis Exporter 的端口为 9121

          # 添加 Kubernetes 服务的 app 标签
          - source_labels: [__meta_kubernetes_service_label_app]
            action: replace
            target_label: app

          # 添加 Kubernetes 命名空间标签
          - source_labels: [__meta_kubernetes_namespace]
            action: replace
            target_label: namespace

          # 添加 Kubernetes 服务名称标签
          - source_labels: [__meta_kubernetes_service_name]
            action: replace
            target_label: service

          # 添加 Kubernetes Pod 名称标签
          - source_labels: [__meta_kubernetes_pod_name]
            action: replace
            target_label: pod

          # 添加 Kubernetes 节点名称标签
          - source_labels: [__meta_kubernetes_pod_node_name]
            action: replace
            target_label: node

          # 添加实例标签(用于区分不同的 Redis 实例)
          - source_labels: [__meta_kubernetes_pod_ip]
            action: replace
            target_label: instance
6.4 操作命令
kubectl create -f prometheus-alert-rules-redis-configmap.yaml

kubectl replace -f prometheus-configmap.yaml

kubectl replace -f prometheus-deployment.yaml

kubectl -n monitoring exec -it prometheus-66967df89b-7gp5d -- ls /etc/prometheus/rules
k8s.rules   node.rules  redis
6.5 操作界面查看alerts状态


7. 总结

  • 该配置实现了 Redis 实例的自动发现和监控。
  • 通过 Redis Exporter 暴露 Redis 指标,Prometheus 自动抓取并存储。
  • 适用于生产环境,支持高可用和动态扩展。