TKE上搭建prometheus

该文章介绍了如何在k8s集群中搭建prometheus来监控集群并通过AlertManager发送告警。

新建namespace部署prometheus

部署prometheus

创建pvc挂载卷挂载prometheus数据

通过configmap配置prometheus配置文件

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: kube-ops
data:
  prometheus.yml: |
    global:
      scrape_interval: 15s
      scrape_timeout: 15s
    scrape_configs:
    - job_name: 'prometheus'
      static_configs:
      - targets: ['localhost:9090']

创建prometheus的pod资源

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: prometheus
  namespace: kube-ops
  labels:
    app: prometheus
spec:
  template:
    metadata:
      labels:
        app: prometheus
    spec:
      serviceAccountName: prometheus
      containers:
      - image: prom/prometheus:v2.4.3
        name: prometheus
        command:
        - "/bin/prometheus"
        args:
        - "--config.file=/etc/prometheus/prometheus.yml"
        - "--storage.tsdb.path=/prometheus"
        - "--storage.tsdb.retention=24h"
        - "--web.enable-admin-api"  # 控制对admin HTTP API的访问，其中包括删除时间序列等功能
        - "--web.enable-lifecycle"  # 支持热更新，直接执行localhost:9090/-/reload立即生效
        ports:
        - containerPort: 9090
          protocol: TCP
          name: http
        volumeMounts:
        - mountPath: "/prometheus"
          subPath: prometheus
          name: data
        - mountPath: "/etc/prometheus"
          name: config-volume
        resources:
          requests:
            cpu: 100m
            memory: 512Mi
          limits:
            cpu: 100m
            memory: 512Mi
      securityContext:
        runAsUser: 0
      volumes:
      - name: data
        persistentVolumeClaim:
          claimName: prometheus
      - configMap:
          name: prometheus-config
        name: config-volume

创建prometheus的svc

apiVersion: v1
kind: Service
metadata:
  name: prometheus
  namespace: kube-ops
  labels:
    app: prometheus
spec:
  selector:
    app: prometheus
  type: NodePort
  ports:
    - name: web
      port: 9090
      targetPort: http

页面访问prometheus

我们就可以通过http://任意节点IP:31160访问 prometheus 的 webui 服务了。

监控集群节点

可以通过node_exporter来获取，顾名思义，node_exporter 就是抓取用于采集服务器节点的各种运行指标，目前 node_exporter 支持几乎所有常见的监控点，比如 conntrack，cpu，diskstats，filesystem，loadavg，meminfo，netstat等

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: kube-ops
  labels:
    name: node-exporter
spec:
  template:
    metadata:
      labels:
        name: node-exporter
    spec:
      hostPID: true
      hostIPC: true
      hostNetwork: true
      containers:
      - name: node-exporter
        image: prom/node-exporter:v0.16.0
        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)($|/)"'
        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: /

我们上面是指定了hostNetwork=true，所以在每个节点上就会绑定一个端口 9100，我们可以通过这个端口去获取到监控指标数据，不需要创建service

让 Prometheus 也能够获取到当前集群中的所有节点信息的话，我们就需要利用 Node 的服务发现模式，同样的prometheus.yml 文件中配置如下的 job 任务即可

prometheus 去发现 Node 模式的服务的时候，访问的端口默认是10250，而现在该端口下面已经没有了/metrics指标数据了，现在 kubelet 只读的数据接口统一通过10255端口进行暴露了，所以我们应该去替换掉这里的端口，但是我们是要替换成10255端口吗？不是的，因为我们是要去配置上面通过node-exporter抓取到的节点指标数据，而我们上面是不是指定了hostNetwork=true，所以在每个节点上就会绑定一个端口9100，所以我们应该将这里的10250替换成9100，但是应该怎样替换呢？

这里我们就需要使用到 Prometheus 提供的relabelconfigs中的replace能力了，relabel 可以在 Prometheus 采集数据之前，通过Target 实例的 Metadata 信息，动态重新写入 Label 的值。除此之外，我们还能根据 Target 实例的 Metadata 信息选择是否采集或者忽略该 Target 实例。比如我们这里就可以去匹配_address这个 Label 标签，然后替换掉其中的端口

最终添加如下job即可

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

由于 kubelet 也自带了一些监控指标数据，就上面我们提到的10255端口，所以我们这里也把 kubelet 的监控任务也一并配置上

  - job_name: 'kubernetes-kubelet'
      kubernetes_sd_configs:
      - role: node
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
        insecure_skip_verify: true
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)

curl一下接口，使配置项生效，去prometheus 的 dashboard 中查看 Targets 是否能够正常抓取数据

容器监控

容器监控我们自然会想到cAdvisor，我们前面也说过cAdvisor已经内置在了 kubelet 组件之中，所以我们不需要单独去安装，cAdvisor的数据路径为/api/v1/nodes//proxy/metrics，同样我们这里使用 node 的服务发现模式，因为每一个节点下面都有 kubelet，自然都有cAdvisor采集到的数据指标，在prometheus.yaml中配置一下即可

    - job_name: 'kubernetes-cadvisor'
      kubernetes_sd_configs:
      - role: node
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      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/cadvisor

reload使配置生效

界面查看cadvisor的target是否生效

Apiservice的监控

集群的 apiserver 在集群内部的 Service 地址，要自动发现 Service 类型的服务，我们就需要用到 role 为 Endpoints 的 kubernetes_sd_configs，我们可以在 ConfigMap 对象中添加上一个 Endpoints 类型的服务的监控任务由于 kubernetes 这个服务对应的端口是443，需要使用 https 协议，所以这里我们需要使用 https 的协议，对应的就需要将对应的 ca 证书配置上，最终配置如下

    - job_name: 'kubernetes-apiservers'
      kubernetes_sd_configs:
      - role: endpoints
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      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

reload使prometheus.yml配置生效

Service的监控

配置一个任务用来专门发现普通类型的 Service

    - job_name: 'kubernetes-service-endpoints'
      kubernetes_sd_configs:
      - role: endpoints
      relabel_configs:
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]
        action: replace
        target_label: __scheme__
        regex: (https?)
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]
        action: replace
        target_label: __metrics_path__
        regex: (.+)
      - source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]
        action: replace
        target_label: __address__
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: $1:$2
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        action: replace
        target_label: kubernetes_name

想自动发现集群中的 Service，就需要我们在 Service 的annotation区域添加prometheus.io/scrape=true的声明我们修改下redis的service，生效后可以在target中查看到

metadata:
  annotations:
    prometheus.io/port: "9121"
    prometheus.io/scrape: "true"

部署kube-state-metrics

kube-state-metrice主要是负责监控pod、DaemonSet、Deployment、Job、CronJob 等各种资源对象的状态

部署kube-state-metrice的pod应用

apiVersion: apps/v1
kind: Deployment
metadata:
  name: kube-state-metrics
  namespace: kube-ops
  labels:
    k8s-app: kube-state-metrics
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
    version: v1.3.0
spec:
  selector:
    matchLabels:
      k8s-app: kube-state-metrics
      version: v1.3.0
  replicas: 1
  template:
    metadata:
      labels:
        k8s-app: kube-state-metrics
        version: v1.3.0
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      priorityClassName: system-cluster-critical
      serviceAccountName: kube-state-metrics
      containers:
      - name: kube-state-metrics
        image: zhaocheng172/kube-state-metrics:v1.3.0
        ports:
        - name: http-metrics
          containerPort: 8080
        - name: telemetry
          containerPort: 8081
        readinessProbe:
          httpGet:
            path: /healthz
            port: 8080
          initialDelaySeconds: 5
          timeoutSeconds: 5
      - name: addon-resizer
        image: zhaocheng172/addon-resizer:1.8.3
        resources:
          limits:
            cpu: 100m
            memory: 30Mi
          requests:
            cpu: 100m
            memory: 30Mi
        env:
          - name: MY_POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: MY_POD_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
        volumeMounts:
          - name: config-volume
            mountPath: /etc/config
        command:
          - /pod_nanny
          - --config-dir=/etc/config
          - --container=kube-state-metrics
          - --cpu=100m
          - --extra-cpu=1m
          - --memory=100Mi
          - --extra-memory=2Mi
          - --threshold=5
          - --deployment=kube-state-metrics
      volumes:
        - name: config-volume
          configMap:
            name: kube-state-metrics-config
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: kube-state-metrics-config
  namespace: kube-ops
  labels:
    k8s-app: kube-state-metrics
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
data:
  NannyConfiguration: |-
    apiVersion: nannyconfig/v1alpha1
    kind: NannyConfiguration

部署kube-state-metrice的service

apiVersion: v1
kind: Service
metadata:
  name: kube-state-metrics
  namespace: kube-ops
  labels:
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
    kubernetes.io/name: "kube-state-metrics"
  annotations:
    prometheus.io/scrape: 'true'
spec:
  ports:
  - name: http-metrics
    port: 8080
    targetPort: http-metrics
    protocol: TCP
  - name: telemetry
    port: 8081
    targetPort: telemetry
    protocol: TCP
  selector:
    k8s-app: kube-state-metrics

kube-state-metrics-service.yaml 对 Service 的定义包含prometheus.io/scrape: 'true'这样的一个annotation，因此 kube-state-metrics 的 endpoint 可以被 Prometheus 自动服务发现

部署granafa

新建pvc做数据持久化

创建grafana的svc

apiVersion: v1
kind: Service
metadata:
  name: grafana
  namespace: kube-ops
  labels:
    app: grafana
spec:
  type: NodePort
  ports:
    - port: 3000
  selector:
    app: grafana

创建gafana的deployment

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: grafana
  namespace: kube-ops
  labels:
    app: grafana
spec:
  revisionHistoryLimit: 10
  template:
    metadata:
      labels:
        app: grafana
    spec:
      containers:
      - name: grafana
        image: grafana/grafana:5.3.4
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 3000
          name: grafana
        env:
        - name: GF_SECURITY_ADMIN_USER
          value: admin
        - name: GF_SECURITY_ADMIN_PASSWORD
          value: admin321
        readinessProbe:
          failureThreshold: 10
          httpGet:
            path: /api/health
            port: 3000
            scheme: HTTP
          initialDelaySeconds: 60
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 30
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /api/health
            port: 3000
            scheme: HTTP
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        resources:
          limits:
            cpu: 100m
            memory: 256Mi
          requests:
            cpu: 100m
            memory: 256Mi
        volumeMounts:
        - mountPath: /var/lib/grafana
          subPath: grafana
          name: storage
      securityContext:
        fsGroup: 472
        runAsUser: 472
      volumes:
      - name: storage
        persistentVolumeClaim:
          claimName: grafana

访问grafana界面

现在我们就可以在浏览器中使用http://<任意节点IP:31838>来访问 grafana 这个服务了：

登录账号密码从deployment的配置文件查看

配置数据源

添加Dashboard

我们这里可以使用Kubernetes cluster monitoring (via Prometheus)(dashboard id 为162)

AlertManager配置告警

配置告警配置文件

apiVersion: v1
kind: ConfigMap
metadata:
  name: alertmanager
  namespace: monitor
  labels:
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: EnsureExists
data:
  config.yml: |
    global:
      resolve_timeout: 5m
      smtp_smarthost: 'smtp.163.com:25'
      smtp_from: 'nwx*****@163.com'
      smtp_auth_username: 'nwx****@163.com'
      smtp_auth_password: '*******'
      smtp_require_tls: false

    templates:
    - '/etc/alertmanager-templates/*.tmpl'


    route:
      group_by: ['alertname']
      group_interval: 1m
      group_wait: 10s
      receiver: default-receiver
      repeat_interval: 1m

    receivers:
    - name: default-receiver
      email_configs:
      - to: "niewx****@163.com"
        html: '{ template "emai.html" . }' # 模板
        headers: { Subject: " { .CommonLabels.instance } { CommonAnnotations.summary }" } #标题

配置告警发送模板文件

apiVersion: v1
kind: ConfigMap
metadata:
  name: alertmanager-templates
  namespace: monitor
data:
  default.tmpl: |
    { define "emai.html" }
    { range .Alerts }
     <pre>
    实例: { .Labels.instance }
    信息: { .Annotations.summary }
    详情: { .Annotations.description }
    时间: { .StartsAt.Format "2006-01-02 15:04:05" }
    </pre>
    { end }
    { end }


    { define "__alertmanager" }AlertManager{ end }
    { define "__subject" }[{ .Status | toUpper }{ if eq .Status "firing" }:{ .Alerts.Firing | len }{ end }] { .GroupLabels.SortedPairs.Values | join " " } { if gt (len .CommonLabels) (len .GroupLabels) }({ with .CommonLabels.Remove .GroupLabels.Names }{ .Values | join " " }{ end }){ end }{ end }
    { define "__single_message_title" }{ range .Alerts.Firing }{ .Labels.alertname } @ { .Annotations.identifier }{ end }{ range .Alerts.Resolved }{ .Labels.alertname } @ { .Annotations.identifier }{ end }{ end }
    { define "custom_title" }[{ .Status | toUpper }{ if eq .Status "firing" }:{ .Alerts.Firing | len }{ end }] { if or (and (eq (len .Alerts.Firing) 1) (eq (len .Alerts.Resolved) 0)) (and (eq (len .Alerts.Firing) 0) (eq (len .Alerts.Resolved) 1)) }{ template "__single_message_title" . }{ end }{ end }
    { define "custom_slack_message" }
    { if or (and (eq (len .Alerts.Firing) 1) (eq (len .Alerts.Resolved) 0)) (and (eq (len .Alerts.Firing) 0) (eq (len .Alerts.Resolved) 1)) }
    { range .Alerts.Firing }
    *报警类型: * { .Labels.service }
    *报警描述: * { .Annotations.description }
    { end }
    { range .Alerts.Resolved }
    *报警恢复: * { .Annotations.resolved }{ end }
    { else }
    { if gt (len .Alerts.Firing) 0 }
    { range .Alerts.Firing }
    *报警类型: * { .Labels.service }
    *报警描述: * { .Annotations.description }
    { end }{ end }
    { if gt (len .Alerts.Resolved) 0 }
    { range .Alerts.Resolved }
    *报警类型: * { .Labels.service }
    *报警恢复: * { .Annotations.resolved }
    { end }{ end }
    { end }
    { end }


    { define "slack.default.title" }{ template "__subject" . }{ end }
    { define "slack.default.username" }{ template "__alertmanager" . }{ end }
    { define "slack.default.fallback" }{ template "slack.default.title" . } | { template "slack.default.titlelink" . }{ end }
    { define "slack.default.pretext" }{ end }
    { define "slack.default.titlelink" }{ template "__alertmanagerURL" . }{ end }
    { define "slack.default.iconemoji" }{ end }
    { define "slack.default.iconurl" }{ end }
    { define "slack.default.text" }{ end }
    { define "slack.default.footer" }{ end }

    { define "wechat.html" }
    { range .Alerts }
    ========start==========
    告警程序: prometheus_alert
    告警级别: { .Labels.severity }
    告警类型: { .Labels.alertname }
    故障主机: { .Labels.instance }
    告警主题: { .Annotations.summary }
    告警详情: { .Annotations.description }
    触发时间: { .StartsAt.Format "2019-01-01 01:01:01" }
    ========end==========
    { end }
    { end }

配置alertmanager容器

我们可以直接在之前的 Prometheus 的 Pod 中添加这个容器，对应的 YAML 资源声明如下：

      containers:
      - args:
        - --config.file=/etc/alertmanager/config.yml
        - --storage.path=/alertmanager/data
        image: prom/alertmanager:v0.15.3
        imagePullPolicy: IfNotPresent
        name: alertmanager
        ports:
        - containerPort: 9093
          name: http
          protocol: TCP
        resources:
          limits:
            cpu: 100m
            memory: 256Mi
          requests:
            cpu: 100m
            memory: 256Mi
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /etc/alertmanager
          name: alertcfg
        - mountPath: /etc/alertmanager-templates
          name: templates-volume

prometheus中配置alermanager

Prometheus 中配置下 AlertManager 的地址，让 Prometheus 能够访问到 AlertManager

alerting:
  alertmanagers:
    - static_configs:
      - targets: ["localhost:9093"]

设置告警规则

直接在prometheus的配置文件中配置告警规则

rules.yml: |2-

        groups:
        - name: test-rule
          rules:
          - alert: NodeFilesystemUsage
            expr: (node_filesystem_size_bytes{device="rootfs"} - node_filesystem_free_bytes{device="rootfs"}) / node_filesystem_size_bytes{device="rootfs"} * 100 > 20
            for: 2m
            labels:
              team: node
            annotations:
              summary: "{$labels.instance}: High Filesystem usage detected"
              description: "{$labels.instance}: Filesystem usage is above 80% (current value is: { $value }"
          - alert: NodeMemoryUsage
            expr: (node_memory_MemTotal_bytes - (node_memory_MemFree_bytes+node_memory_Buffers_bytes+node_memory_Cached_bytes )) / node_memory_MemTotal_bytes * 100 > 20
            for: 2m
            labels:
              team: node
            annotations:
              summary: "{$labels.instance}: High Memory usage detected"
              description: "{$labels.instance}: Memory usage is above 80% (current value is: { $value }"
          - alert: NodeCPUUsage
            expr: (100 - (avg by (instance) (irate(node_cpu{job="kubernetes-node-exporter",mode="idle"}[5m])) * 100)) > 20
            for: 2m
            labels:
              team: node
            annotations:
              summary: "{$labels.instance}: High CPU usage detected"
              description: "{$labels.instance}: CPU usage is above 80% (current value is: { $value }"

查看告警

在这个页面中我们可以进行一些操作，比如过滤、分组等等，里面还有两个新的概念：Inhibition(抑制)和 Silences(静默)。

Inhibition：如果某些其他警报已经触发了，则对于某些警报，Inhibition 是一个抑制通知的概念。例如：一个警报已经触发，它正在通知整个集群是不可达的时，Alertmanager 则可以配置成关心这个集群的其他警报无效。这可以防止与实际问题无关的数百或数千个触发警报的通知，Inhibition 需要通过上面的配置文件进行配置。
Silences：静默是一个非常简单的方法，可以在给定时间内简单地忽略所有警报。Silences 基于 matchers配置，类似路由树。来到的警告将会被检查，判断它们是否和活跃的 Silences 相等或者正则表达式匹配。如果匹配成功，则不会将这些警报发送给接收者。

由于全局配置中我们配置的repeat_interval: 5m，所以正常来说，上面的测试报警如果一直满足报警条件(CPU使用率大于20%)的话，那么每5分钟我们就可以收到一条报警邮件。

配置ingress通过域名访问

将域名解析到对应的vip上

配置好ingress的转发规则

通过域名来访问

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