什么是 Prometheus

Prometheus 是由 SoundCloud 开源监控告警解决方案，从 2012 年开始编写代码，再到 2015 年 github 上开源以来，已经吸引了 9k+ 关注，以及很多大公司的使用；2016 年 Prometheus 成为继 k8s 后，第二名 CNCF成员。作为新一代开源解决方案，很多理念与 Google SRE 运维之道不谋而合。

基础架构：

 

image

安装prometheus：
1.创建prometheus和altertmanager（prometheus的报警模块）的configmap文件
下面用到的yaml配置文件已放到github上有需要的可以自己clone
cat prometheus-cm.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: kube-ops
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: kube-ops
data:
  prometheus.yml: |
    global:
      scrape_interval: 30s
      scrape_timeout: 30s
    rule_files:
    - /etc/prometheus/rules.yml
    alerting:
      alertmanagers:
        - static_configs:
          - targets: ["localhost:9093"]
    scrape_configs:
    - job_name: 'prometheus'
      static_configs:
        - targets: ['localhost:9090']
    - 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
    - job_name: 'kubernetes-nodes'
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      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/${1}/proxy/metrics
    - job_name: 'kubernetes-cadvisor'
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      kubernetes_sd_configs:
      - role: node
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
      - target_label: __address__
        replacement: kubernetes.default.svc:443
      - source_labels: [__meta_kubernetes_node_name]
        regex: (.+)
        target_label: __metrics_path__
        replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor
    - job_name: 'kubernetes-node-exporter'
      scheme: http
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      kubernetes_sd_configs:
      - role: node
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
      - source_labels: [__meta_kubernetes_role]
        action: replace
        target_label: kubernetes_role
      - source_labels: [__address__]
        regex: '(.*):10250'
        replacement: '${1}:31672'
        target_label: __address__
    - 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:$2
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        action: replace
        target_label: kubernetes_name
    - job_name: 'kubernetes-services'
      metrics_path: /probe
      params:
        module: [http_2xx]
      kubernetes_sd_configs:
      - role: service
      relabel_configs:
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_probe]
        action: keep
        regex: true
      - source_labels: [__address__]
        target_label: __param_target
      - target_label: __address__
        replacement: blackbox-exporter.example.com:9115
      - source_labels: [__param_target]
        target_label: instance
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        target_label: kubernetes_name
  rules.yml: |
    groups:
    - name: test-rule
      rules:
      - alert: NodeFilesystemUsage
        expr: (node_filesystem_size{device="rootfs"} - node_filesystem_free{device="rootfs"}) / node_filesystem_size{device="rootfs"} * 100 > 80
        for: 2m
        labels:
          team: node
        annotations:
          summary: "{{$labels.instance}}: High Filesystem usage detected"
          description: "{{$labels.instance}}: Filesystem usage is above 80% (current value is: {{ $value }}"
      - alert: NodeMemoryUsage
        expr: (node_memory_MemTotal - (node_memory_MemFree+node_memory_Buffers+node_memory_Cached )) / node_memory_MemTotal * 100 > 80
        for: 2m
        labels:
          team: node
        annotations:
          summary: "{{$labels.instance}}: High Memory usage detected"
          description: "{{$labels.instance}}: Memory usage is above 80% (current value is: {{ $value }}"
      - alert: NodeCPUUsage
        expr: (100 - (avg by (instance) (irate(node_cpu{job="kubernetes-node-exporter",mode="idle"}[5m])) * 100)) > 80
        for: 2m
        labels:
          team: node
        annotations:
          summary: "{{$labels.instance}}: High CPU usage detected"
          description: "{{$labels.instance}}: CPU usage is above 80% (current value is: {{ $value }}"
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: alertmanager
  namespace: kube-ops
data:
  config.yml: |-
    global:
      resolve_timeout: 5m
    route:
      receiver: webhook
      group_wait: 30s
      group_interval: 5m
      repeat_interval: 4h
      group_by: [alertname]
      routes:
      - receiver: webhook
        group_wait: 10s
        match:
          team: node
    receivers:
    - name: webhook
      webhook_configs:
      - url: 'http://apollo/hooks/dingtalk/'
        send_resolved: true
      - url: 'http://apollo/hooks/prome/'
        send_resolved: true

kubectl apply -f prometheus-cm.yaml

2.部署node-exporter（在每个节点都安装，需要用daemonset模式）
vim node-exporter.yaml

---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: kube-ops
  labels:
    k8s-app: node-exporter
spec:
  template:
    metadata:
      labels:
        k8s-app: node-exporter
    spec:
      containers:
      - image: prom/node-exporter
        name: node-exporter
        ports:
        - containerPort: 9100
          protocol: TCP
          name: http

---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: node-exporter
  name: node-exporter
  namespace: kube-ops
spec:
  ports:
  - name: http
    port: 9100
    nodePort: 31672
    protocol: TCP
  type: NodePort
  selector:
    k8s-app: node-exporter

kubectl apply -f node-exporter.yaml

3.安装prometheus+alertmanager（注意这里的data数据盘是使用cephfs pv pvc挂载的，需要自行创建，pv pvc的模板前面的github链接中可以找到）
vim prometheus-deployment.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  labels:
    k8s-app: prometheus
  name: prometheus
  namespace: kube-ops
spec:
  replicas: 1
  template:
    metadata:
      labels:
        k8s-app: prometheus
    spec:
      serviceAccountName: prometheus
      securityContext:
        runAsUser: 0
      containers:
      - image: prom/prometheus:v2.0.0
        name: prometheus
        command:
        - "/bin/prometheus"
        args:
        - "--config.file=/etc/prometheus/prometheus.yml"
        - "--storage.tsdb.path=/prometheus"
        - "--storage.tsdb.retention=24h"
        ports:
        - containerPort: 9090
          protocol: TCP
          name: http
        volumeMounts:
        - mountPath: "/prometheus"
          name: data
        - mountPath: "/etc/prometheus"
          name: config-volume
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
          limits:
            cpu: 200m
            memory: 1Gi
      - image: quay.io/prometheus/alertmanager:v0.12.0
        name: alertmanager
        args:
        - "-config.file=/etc/alertmanager/config.yml"
        - "-storage.path=/alertmanager"
        ports:
        - containerPort: 9093
          protocol: TCP
          name: http
        volumeMounts:
        - name: alertmanager-config-volume
          mountPath: /etc/alertmanager
        resources:
          requests:
            cpu: 50m
            memory: 50Mi
          limits:
            cpu: 200m
            memory: 200Mi
      volumes:
      - name: data
        persistentVolumeClaim:
          claimName: prometheus-pvc
      - configMap:
          name: prometheus-config
        name: config-volume
      - name: alertmanager-config-volume
        configMap:
          name: alertmanager

kubectl apply -f prometheus-deployment.yaml

4.暴露prometheus端口（也可以使用ingress规则暴露，可自行选择，下面的grafana选择用ingress暴露）
vim prometheus-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: prometheus
  namespace: kube-ops
  labels:
    k8s-app: prometheus
spec:
  selector:
    k8s-app: prometheus
  type: NodePort
  ports:
    - name: web
      port: 9090
      targetPort: http

kubectl apply -f prometheus-svc.yaml

5.安装grafana（prometheus自带的图形展示不行很理想，所以要搭配强大的图形展示工具grafana）
安装grafnan的时候用到了cephfs pv pvc和ingress。
vim grafana.yaml

apiVersion: v1
kind: Service
metadata:
  labels:
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: grafana
  name: grafana
  namespace: kube-ops
spec:
  ports:
  - port: 3000
    targetPort: 3000
  selector:
    k8s-app: grafana
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  labels:
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: grafana
  name: grafana-ingress
  namespace: kube-ops
spec:
  rules:
  - host: grafana.io
    http:
      paths:
      - path: /
        backend:
          serviceName: grafana
          servicePort: 3000
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: prometheus-pv
  namespace: kube-ops
spec:
  capacity:
    storage: 50Gi
  accessModes:
    - ReadWriteMany
  cephfs:
    monitors:
      - 192.168.0.231:6789
      - 192.168.0.242:6789
      - 192.168.0.211:6789
    path: /data/system/grafana
    user: admin
    secretRef:
      name: ceph-secret
    readOnly: false
  persistentVolumeReclaimPolicy: Recycle
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: prometheus-pvc
  namespace: kube-ops
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 50Gi
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: grafana
  namespace: kube-ops
spec:
  replicas: 1
  template:
    metadata:
      labels:
        task: monitoring
        k8s-app: grafana
    spec:
      containers:
      - name: grafana
        image: gcr.io/google_containers/heapster-grafana-amd64:v4.4.3
        ports:
        - containerPort: 3000
          protocol: TCP
        volumeMounts:
        - mountPath: /var
          name: grafana
          subPath: grafana/data
        - mountPath: /ssl
          name: ssl
        resources:
          limits:
            cpu: 200m
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 100Mi
        env:
        - name: INFLUXDB_HOST
          value: influxdb.kube-system
        - name: GF_SERVER_HTTP_PORT
          value: "3000"
        - name: GF_AUTH_BASIC_ENABLED
          value: "true"
        - name: GF_AUTH_ANONYMOUS_ENABLED
          value: "false"
        - name: GF_SERVER_ROOT_URL
          value: /
        - name: GF_SMTP_ENABLED
          value: "true"
        - name: GF_ALERTING_ENABLED
          value: "true"
        - name: GF_ALERTING_EXECUTE_ALERTS
          value: "true"
        readinessProbe:
          httpGet:
            path: /login
            port: 3000
          initialDelaySeconds: 30
          timeoutSeconds: 2
      volumes:
      - name: ssl
        hostPath:
          path: /etc/ssl/certs
      - name: grafana
        persistentVolumeClaim:
          claimName: prometheus-pvc

kubectl apply -f grafana.yaml

这里的ingress是选择 grafana.io作为域名，需要将本地的hosts解析成nodeip（没做lb的话）。
进入到以下界面，填写数据信息

image.png

随后设置dashboard页面，推荐下面的两款。
https://grafana.com/dashboards/1621
https://grafana.com/dashboards/315
这里选择使用315
效果展示如下图所示

image.png