kubernetes监控-prometheus（十六）

监控方案

cAdvisor+Heapster+InfluxDB+Grafana	Y	简单	容器监控
cAdvisor/exporter+Prometheus+Grafana	Y	扩展性好	容器，应用，主机全方面监控

Prometheus+Grafana是监控告警解决方案里的后起之秀

通过各种exporter采集不同维度的监控指标，并通过Prometheus支持的数据格式暴露出来，Prometheus定期pull数据并用Grafana展示，异常情况使用AlertManager告警。

通过cadvisor采集容器、Pod相关的性能指标数据，并通过暴露的/metrics接口用prometheus抓取

通过prometheus-node-exporter采集主机的性能指标数据，并通过暴露的/metrics接口用prometheus抓取

应用侧自己采集容器中进程主动暴露的指标数据（暴露指标的功能由应用自己实现，并添加平台侧约定的annotation，平台侧负责根据annotation实现通过Prometheus的抓取）

通过kube-state-metrics采集k8s资源对象的状态指标数据，并通过暴露的/metrics接口用prometheus抓取

通过etcd、kubelet、kube-apiserver、kube-controller-manager、kube-scheduler自身暴露的/metrics获取节点上与k8s集群相关的一些特征指标数据。

实现思路

监控指标	具体实现	举例
Pod性能	cAdvisor	容器CPU，内存利用率
Node性能	node-exporter	节点CPU，内存利用率
K8S资源对象	kube-state-metrics	Pod/Deployment/Service

k8s中部署prometheus

官网：https://prometheus.io

下载yaml文件：https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/prometheus

修改yaml文件

#使用nfs存储
[root@localhost prometheus]# kubectl get storageclass
NAME                  PROVISIONER      AGE
managed-nfs-storage   fuseim.pri/ifs   9d
[root@localhost prometheus]# sed -i s/standard/managed-nfs-storage/ prometheus-statefulset.yaml

#修改service使用NOdePort
[root@localhost prometheus]# vim prometheus-service.yaml 
。。。。
spec:
  type: NodePort
  ports:
    - name: http
      port: 9090
      protocol: TCP
      targetPort: 9090
  selector:
    k8s-app: prometheus

启动prometheus

[root@localhost prometheus]# kubectl apply -f prometheus-rbac.yaml 
serviceaccount/prometheus created
clusterrole.rbac.authorization.k8s.io/prometheus created
clusterrolebinding.rbac.authorization.k8s.io/prometheus created
[root@localhost prometheus]# kubectl apply -f prometheus-configmap.yaml 
configmap/prometheus-config created
[root@localhost prometheus]# kubectl apply -f prometheus-statefulset.yaml 
statefulset.apps/prometheus created
[root@localhost prometheus]# vim prometheus-service.yaml 
[root@localhost prometheus]# kubectl apply -f prometheus-service.yaml
service/prometheus created

查看

[root@localhost prometheus]# kubectl get pod,svc -n kube-system
NAME                                        READY   STATUS    RESTARTS   AGE
pod/coredns-5b8c57999b-z9jh8                1/1     Running   1          16d
pod/kubernetes-dashboard-644c96f9c6-bvw8w   1/1     Running   1          16d
pod/prometheus-0                            2/2     Running   0          2m40s

NAME                           TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)          AGE
service/kube-dns               ClusterIP   10.0.0.2     <none>        53/UDP,53/TCP    16d
service/kubernetes-dashboard   NodePort    10.0.0.84    <none>        443:30001/TCP    16d
service/prometheus             NodePort    10.0.0.89    <none>        9090:41782/TCP   39s
[root@localhost prometheus]# kubectl get pv,pvc -n kube-system
NAME                                                                                                 CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                                      STORAGECLASS          REASON   AGE
persistentvolume/kube-system-prometheus-data-prometheus-0-pvc-0e92f36c-8d9e-11e9-b018-525400828c1f   16Gi       RWO            Delete           Bound    kube-system/prometheus-data-prometheus-0   managed-nfs-storage            25m

NAME                                                 STATUS   VOLUME                                                                              CAPACITY   ACCESS MODES   STORAGECLASS          AGE
persistentvolumeclaim/prometheus-data-prometheus-0   Bound    kube-system-prometheus-data-prometheus-0-pvc-0e92f36c-8d9e-11e9-b018-525400828c1f   16Gi       RWO            managed-nfs-storage   25m

访问

部署grafana

[root@localhost prometheus]# cat grafana.yaml 
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: grafana
  namespace: kube-system
spec:
  serviceName: "grafana"
  replicas: 1
  selector:
    matchLabels:
      app: grafana
  template:
    metadata:
      labels:
        app: grafana
    spec:
      containers:
        - name: grafana
          image: grafana/grafana
          resources:
            limits:
              cpu: 100m
              memory: 256Mi
            requests:
              cpu: 100m
              memory: 256Mi
          volumeMounts:
            - name: grafana-data
              mountPath: /var/lib/grafana
              subPath: grafana
      securityContext:
        fsGroup: 472
        runAsUser: 472
  volumeClaimTemplates:
  - metadata:
      name: grafana-data
    spec:
      storageClassName: managed-nfs-storage 
      accessModes:
        - ReadWriteOnce
      resources:
        requests:
          storage: "1Gi"

---

apiVersion: v1
kind: Service
metadata:
  name: grafana
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 3000
    nodePort: 30007
  selector:
    app: grafana

[root@localhost prometheus]# kubectl apply -f grafana.yaml 
statefulset.apps/grafana created
service/grafana created

[root@localhost prometheus]# kubectl get pod,svc -n kube-system
NAME                                        READY   STATUS    RESTARTS   AGE
pod/coredns-5b8c57999b-z9jh8                1/1     Running   1          17d
pod/grafana-0                               1/1     Running   0          45s
pod/kubernetes-dashboard-644c96f9c6-bvw8w   1/1     Running   1          17d
pod/prometheus-0                            2/2     Running   0          25h

NAME                           TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)          AGE
service/grafana                NodePort    10.0.0.78    <none>        80:30007/TCP     44s
service/kube-dns               ClusterIP   10.0.0.2     <none>        53/UDP,53/TCP    17d
service/kubernetes-dashboard   NodePort    10.0.0.84    <none>        443:30001/TCP    17d
service/prometheus             NodePort    10.0.0.89    <none>        9090:41782/TCP   25h

访问

监控k8s集群中的pod

kubelet的节点使用cAdvisor提供的metrics接口获取该节点所有容器相关的性能指标数据。

暴露接口地址：

https://NodeIP:10255/metrics/cadvisor

https://NodeIP:10250/metrics/cadvisor

导入grafana模板

https://grafana.com/grafana/download

集群资源监控：3119

监控k8s集群中的node

使用文档：https://prometheus.io/docs/guides/node-exporter/

GitHub：https://github.com/prometheus/node_exporter

exporter列表：https://prometheus.io/docs/instrumenting/exporters/

所有node节点部署node_exporter

wget https://github.com/prometheus/node_exporter/releases/download/v0.17.0/node_exporter-0.17.0.linux-amd64.tar.gz

tar zxf node_exporter-0.17.0.linux-amd64.tar.gz
mv node_exporter-0.17.0.linux-amd64 /usr/local/node_exporter

cat <<EOF >/usr/lib/systemd/system/node_exporter.service
[Unit]
Description=https://prometheus.io

[Service]
Restart=on-failure
ExecStart=/usr/local/node_exporter/node_exporter --collector.systemd --collector.systemd.unit-whitelist=(docker|kubelet|kube-proxy|flanneld).service

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable node_exporter
systemctl restart node_exporter

修改prometheus-configmap.yaml，并重新部署

查看prometheus是否收集到kubernetes-nodes

导入grafana模板

集群资源监控：9276

监控k8s资源对象

https://github.com/kubernetes/kube-state-metrics

kube-state-metrics是一个简单的服务，它监听Kubernetes API服务器并生成有关对象状态的指标。它不关注单个Kubernetes组件的运行状况，而是关注内部各种对象的运行状况，例如部署，节点和容器。

[root@localhost prometheus]# kubectl apply -f kube-state-metrics-rbac.yaml 
serviceaccount/kube-state-metrics created
clusterrole.rbac.authorization.k8s.io/kube-state-metrics created
role.rbac.authorization.k8s.io/kube-state-metrics-resizer created
clusterrolebinding.rbac.authorization.k8s.io/kube-state-metrics created
rolebinding.rbac.authorization.k8s.io/kube-state-metrics created
[root@localhost prometheus]# vim kube-state-metrics-deployment.yaml 
[root@localhost prometheus]# kubectl apply -f kube-state-metrics-deployment.yaml
deployment.apps/kube-state-metrics created
configmap/kube-state-metrics-config created
[root@localhost prometheus]# kubectl apply -f kube-state-metrics-service.yaml 
service/kube-state-metrics created

导入grafana模板

集群资源监控：6417

在K8S中部署Alertmanager

部署Alertmanager

[root@localhost prometheus]# sed -i s/standard/managed-nfs-storage/ alertmanager-pvc.yaml
[root@localhost prometheus]# kubectl apply -f  alertmanager-configmap.yaml 
configmap/alertmanager-config created
[root@localhost prometheus]# kubectl apply -f  alertmanager-pvc.yaml 
persistentvolumeclaim/alertmanager created
[root@localhost prometheus]# kubectl apply -f  alertmanager-deployment.yaml 
deployment.apps/alertmanager created
[root@localhost prometheus]# kubectl apply -f  alertmanager-service.yaml 
service/alertmanager created

[root@localhost prometheus]# kubectl get pod -n kube-system
NAME                                    READY   STATUS    RESTARTS   AGE
alertmanager-6b5bbd5bd4-lgjn8           2/2     Running   0          95s
coredns-5b8c57999b-z9jh8                1/1     Running   1          20d
grafana-0                               1/1     Running   3          2d22h
kube-state-metrics-f86fd9f4f-j4rdc      2/2     Running   0          3h2m
kubernetes-dashboard-644c96f9c6-bvw8w   1/1     Running   1          20d
prometheus-0                            2/2     Running   0          4d

配置Prometheus与Alertmanager通信

[root@localhost prometheus]# vim prometheus-configmap.yaml
。。。。
    alerting:
      alertmanagers:
      - static_configs:
          - targets: ["alertmanager:80"]
[root@localhost prometheus]# kubectl apply -f prometheus-configmap.yaml 
configmap/prometheus-config configured

配置告警

prometheus指定rules目录

configmap存储告警规则

[root@localhost prometheus]# cat prometheus-rules.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-rules
  namespace: kube-system
data:
  general.rules: |
    groups:
    - name: general.rules
      rules:
      - alert: InstanceDown
        expr: up == 0
        for: 1m
        labels:
          severity: error 
        annotations:
          summary: "Instance {{ $labels.instance }} 停止工作"
          description: "{{ $labels.instance }} job {{ $labels.job }} 已经停止5分钟以上."
  node.rules: |
    groups:
    - name: node.rules
      rules:
      - alert: NodeFilesystemUsage
        expr: 100 - (node_filesystem_free_bytes{fstype=~"ext4|xfs"} / node_filesystem_size_bytes{fstype=~"ext4|xfs"} * 100) > 80 
        for: 1m
        labels:
          severity: warning 
        annotations:
          summary: "Instance {{ $labels.instance }} : {{ $labels.mountpoint }} 分区使用率过高"
          description: "{{ $labels.instance }}: {{ $labels.mountpoint }} 分区使用大于80% (当前值: {{ $value }})"

      - alert: NodeMemoryUsage
        expr: 100 - (node_memory_MemFree_bytes+node_memory_Cached_bytes+node_memory_Buffers_bytes) / node_memory_MemTotal_bytes * 100 > 80
        for: 1m
        labels:
          severity: warning
        annotations:
          summary: "Instance {{ $labels.instance }} 内存使用率过高"
          description: "{{ $labels.instance }}内存使用大于80% (当前值: {{ $value }})"

      - alert: NodeCPUUsage    
        expr: 100 - (avg(irate(node_cpu_seconds_total{mode="idle"}[5m])) by (instance) * 100) > 60 
        for: 1m
        labels:
          severity: warning
        annotations:
          summary: "Instance {{ $labels.instance }} CPU使用率过高"       
          description: "{{ $labels.instance }}CPU使用大于60% (当前值: {{ $value }})"

[root@localhost prometheus]# kubectl apply -f prometheus-rules.yaml
configmap/prometheus-rules created

configmap挂载到容器rules目录

[root@localhost prometheus]# vim prometheus-statefulset.yaml
......
          volumeMounts:
            - name: config-volume
              mountPath: /etc/config
            - name: prometheus-data
              mountPath: /data
              subPath: ""
            - name: prometheus-rules
              mountPath: /etc/config/rules
      terminationGracePeriodSeconds: 300
      volumes:
        - name: config-volume
          configMap:
            name: prometheus-config
        - name: prometheus-rules
          configMap:
            name: prometheus-rules
......

怎加alertmanager的告警配置

[root@localhost prometheus]# cat alertmanager-configmap.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: alertmanager-config
  namespace: kube-system
  labels:
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: EnsureExists
data:
  alertmanager.yml: |
    global: 
      resolve_timeout: 5m
      smtp_smarthost: 'smtp.163.com:25'
      smtp_from: 'xxxxx@163.com'
      smtp_auth_username: 'xxxxx@163.com'
      smtp_auth_password: 'xxxxx'
    receivers:
    - name: default-receiver
      email_configs:
      - to: "xxxxx@qq.com"
    route:
      group_interval: 1m
      group_wait: 10s
      receiver: default-receiver
      repeat_interval: 1m

[root@localhost prometheus]# kubectl apply -f alertmanager-configmap.yaml
configmap/alertmanager-config configured

邮件告警