kubernetes监控方案--cAdvisor+Heapster+InfluxDB+Grafana

一、Kubernetes监控指标

Cluster监控
• 节点资源利用率
• 节点数
• 运行Pods

Pod监控
• Kubernetes指标
• 容器指标
• 应用程序

二、Kubernetes监控方案

1、cAdvisor为谷歌开源的专门用于监控容器的服务，已经集成到了k8s里面（数据采集Agent）

Kubernetes有个出名的监控agent—cAdvisor。在每个kubernetes Node上都会运行cAdvisor，它会收集本机以及容器的监控数据(cpu,memory,filesystem,network,uptime)。在较新的版本中，K8S已经将cAdvisor功能集成到kubelet组件中。每个Node节点可以直接进行web访问。

2、Heapster是容器集群监控和性能分析工具，天然的支持Kubernetes和CoreOS。但是Heapster已经退休了！（数据收集）

Heapster是一个收集者，Heapster可以收集Node节点上的cAdvisor数据，将每个Node上的cAdvisor的数据进行汇总，还可以按照kubernetes的资源类型来集合资源，比如Pod、Namespace，可以分别获取它们的CPU、内存、网络和磁盘的metric。默认的metric数据聚合时间间隔是1分钟。还可以把数据导入到第三方工具(如InfluxDB)。

Kubernetes原生dashboard的监控图表信息来自heapster。在Horizontal Pod Autoscaling中也用到了Heapster，HPA将Heapster作为Resource Metrics API，向其获取metric。

https://github.com/kubernetes-retired/heapster

3、InfluxDB是一个开源的时序数据库。（数据存储）

4、grafana是一个开源的数据展示工具。（数据展示）

三、部署监控

由于cAdvisor已经在k8s里面集成了，其他部件部署顺序：influxDB->Heapster->grafana

1、部署influxDB

cat influxdb.yaml

采用Deployment方式，命名空间为kube-system

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: monitoring-influxdb
  namespace: kube-system
spec:
  replicas: 1
  template:
    metadata:
      labels:
        task: monitoring
        k8s-app: influxdb
    spec:
      containers:
      - name: influxdb
        image: registry.cn-hangzhou.aliyuncs.com/google-containers/heapster-influxdb-amd64:v1.1.1
        volumeMounts:
        - mountPath: /data
          name: influxdb-storage
      volumes:
      - name: influxdb-storage
        emptyDir: {}

---

apiVersion: v1
kind: Service
metadata:
  labels:
    task: monitoring
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: monitoring-influxdb
  name: monitoring-influxdb
  namespace: kube-system
spec:
  ports:
  - port: 8086
    targetPort: 8086
  selector:
    k8s-app: influxdb

2、部署heapster

Heapster首先从apiserver获取集群中所有Node的信息，然后通过这些Node上的kubelet获取有用数据，而kubelet本身的数据则是从cAdvisor得到。所有获取到的数据都被推到Heapster配置的后端存储中，并还支持数据的可视化。

由于Heapster需要从apiserver获取数据，所以需要对其进行授权。用户为cluster-admin，集群管理员用户。

cat heapster.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: heapster
  namespace: kube-system

---

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: heapster
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io
subjects:
  - kind: ServiceAccount
    name: heapster
    namespace: kube-system

---

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: heapster
  namespace: kube-system
spec:
  replicas: 1
  template:
    metadata:
      labels:
        task: monitoring
        k8s-app: heapster
    spec:
      serviceAccountName: heapster
      containers:
      - name: heapster
        image: registry.cn-hangzhou.aliyuncs.com/google-containers/heapster-amd64:v1.4.2
        imagePullPolicy: IfNotPresent
        command:
        - /heapster
        - --source=kubernetes:https://kubernetes.default
        - --sink=influxdb:http://monitoring-influxdb:8086

---

apiVersion: v1
kind: Service
metadata:
  labels:
    task: monitoring
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: Heapster
  name: heapster
  namespace: kube-system
spec:
  ports:
  - port: 80
    targetPort: 8082
  selector:
    k8s-app: heapster

3、部署grafana

cat grafana.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: monitoring-grafana
  namespace: kube-system
spec:
  replicas: 1
  template:
    metadata:
      labels:
        task: monitoring
        k8s-app: grafana
    spec:
      containers:
      - name: grafana
        image: registry.cn-hangzhou.aliyuncs.com/google-containers/heapster-grafana-amd64:v4.4.1
        ports:
          - containerPort: 3000
            protocol: TCP
        volumeMounts:
        - mountPath: /var
          name: grafana-storage
        env:
        - name: INFLUXDB_HOST
          value: monitoring-influxdb
        - name: GF_AUTH_BASIC_ENABLED
          value: "false"
        - name: GF_AUTH_ANONYMOUS_ENABLED
          value: "true"
        - name: GF_AUTH_ANONYMOUS_ORG_ROLE
          value: Admin
        - name: GF_SERVER_ROOT_URL
          value: /
      volumes:
      - name: grafana-storage
        emptyDir: {}

---

apiVersion: v1
kind: Service
metadata:
  labels:
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: monitoring-grafana
  name: monitoring-grafana
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port : 80
    targetPort: 3000
  selector:
    k8s-app: grafana

已经部件部署完成后，则进入grafana界面：