---
title: Kubernetes中使用Prometheus对集群节点做监控
abbrlink: 61baae6f
categories:
  - 监控
tags:
  - k8s
  - Prometheus
  - prometheus
  - node_exporter
  - monitor
cover: 'https://static.zahui.fan/images/202211212221065.svg'
date: 2022-09-20 16:28:16
---


正常情况下使用Prometheus对机器做监控，比如监控CPU、内存、磁盘等信息，  都是在机器上安装一个node exporter， 然后将metrics接入到Prometheus中。在k8s环境下， 我们可以使用k8s来管理， 实现自动化监控。

node exporter是针对主机节点的， 需要在每台node节点上安装， 那么daemonset控制器是最合理的选择。 网络使用Host Network模式， 在主机上直接暴露一个端口。


## 部署node exporter

使用yaml

```yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: monitor
  labels:
    name: node-exporter
spec:
  selector:
    matchLabels:
      name: node-exporter
  template:
    metadata:
      labels:
        name: node-exporter
    spec:
      hostPID: true
      hostIPC: true
      hostNetwork: true
      containers:
      - name: node-exporter
        image: prom/node-exporter:v1.3.1
        ports:
        - containerPort: 9100
        resources:
          requests:
            cpu: 0.15
        securityContext:
          privileged: true
        args:
        - --path.procfs
        - /host/proc
        - --path.sysfs
        - /host/sys
        - --collector.filesystem.ignored-mount-points
        - '"^/(sys|proc|dev|host|etc)($|/)"'
        - '--web.listen-address=:9100'
        volumeMounts:
        - name: dev
          mountPath: /host/dev
        - name: proc
          mountPath: /host/proc
        - name: sys
          mountPath: /host/sys
        - name: rootfs
          mountPath: /rootfs
      tolerations:
      - key: "node-role.kubernetes.io/master"
        operator: "Exists"
        effect: "NoSchedule"
      volumes:
        - name: proc
          hostPath:
            path: /proc
        - name: dev
          hostPath:
            path: /dev
        - name: sys
          hostPath:
            path: /sys
        - name: rootfs
          hostPath:
            path: /
```

## 配置prometheus

关于Prometheus标签处理， 可以看[这篇文章](/posts/prometheus_tag)

```yml
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: monitor
data:
  web.yml: |
    basic_auth_users:
      admin: $2y$05$UKSS18ztdsUNoEuXYScr2OE1TCMe1hWnmD6JuwUi/uPTJayHIakae
  prometheus.yml: |
    global:
      scrape_interval:     15s
      evaluation_interval: 15s
      
      # 全局标签
      external_labels:
        env: prod
        dept: ops
        project: datong

    scrape_configs:
    # 此处省略掉一部分JOB
      # 自动发现集群的节点
      - job_name: 'kubernetes-node'
        kubernetes_sd_configs:
        - role: node
        relabel_configs:
        - source_labels: [__address__]
          regex: '(.*):10250'
          replacement: '${1}:9100'
          target_label: __address__
          action: replace
        - action: labelmap
          regex: __meta_kubernetes_node_label_(.+)
```

这里是利用了Prometheus的元数据，将kubelet的地址更换成了node exporter的地址， 端口换成了9100来实现自动化监控的。