K8S集群监控—cAdvisor+Heapster+InfluxDB+Grafana

容器的监控方案有多种，如单台docker主机的监控，可以使用docker stats或者cAdvisor web页面进行监控。但针对于Kubernetes这种容器编排工具而言docker单主机的监控已经不足以满足需求，在Kubernetes的生态圈中也诞生了一个个监控方案，如常用的dashboard，部署cAdvisor+Heapster+InfluxDB+Grafana监控方案，部署Prometheus和Grafana监控方案等。在这里主要讲述一下cAdvisor+Heapster监控方案。

# docker stats

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Google的 cAdvisor 是另一个知名的开源容器监控工具，cAdvisor是docker容器创建后自动起的一个容器进程，用户可以通过Web界面访问当前节点和容器的性能数据(CPU、内存、网络、磁盘、文件系统等等)，非常详细。cAdvisor可以直接通过访问docker主机的4194端口访问。

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一、集群监控原理

cAdvisor：容器数据收集。
Heapster：集群监控数据收集，汇总所有节点监控数据。
InfluxDB：时序数据库，存储监控数据。
Grafana：可视化展示。

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由图可知，cAdvisor用于获取k8s node节点上的容器数据，内存，CPU，Disk用量，网络流量等，cAdvisor只支持实时存储，不支持持久化存储，由Heapster汇总所有节点的数据，交由InfluxDB来做持久化存储，最后再由Grafana作为前端的Web展示页面来使用。

二、搭建cAdvisor+Heapster+InfluxDB+Grafana

①从官网上拉取安装包

获取v1.5.2heapster+influxdb+grafana安装yaml文件到 heapster release 页面下载最新版本的 heapster：
# wget https://github.com/kubernetes/heapster/archive/v1.5.2.zip

# unzip v1.5.2.zip

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②修改yaml文件，如镜像路径(国外镜像，不×××下载不了)

修改influxdb.yam并启用

注意：数据库需要最先启用，后面收集到的数据才能保存

[root@node-1 monitor]# cat influxdb.yaml
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
    # For use as a Cluster add-on (https://github.com/kubernetes/kubernetes/tree/master/cluster/addons)
    # If you are NOT using this as an addon, you should comment out this line.
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: monitoring-influxdb
name: monitoring-influxdb
namespace: kube-system
spec:
type: NodePort
ports:
- nodePort: 31001
    port: 8086
    targetPort: 8086
selector:
    k8s-app: influxdb

# kubectl create -f influxdb.yaml

修改heapster.yaml

[root@node-1 monitor]# cat heapster.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: heapster
namespace: kube-system

---

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

---

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
    # For use as a Cluster add-on (https://github.com/kubernetes/kubernetes/tree/master/cluster/addons)
    # If you are NOT using this as an addon, you should comment out this line.
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: Heapster
name: heapster
namespace: kube-system
spec:
ports:
- port: 80
    targetPort: 8082
selector:
    k8s-app: heapster

# kubectl create -f heapster.yaml

修改grafana.yaml

[root@node-1 monitor]# 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: /etc/ssl/certs
          name: ca-certificates
          readOnly: true
        - mountPath: /var
          name: grafana-storage
        env:
        - name: INFLUXDB_HOST
          value: monitoring-influxdb
        - name: GF_SERVER_HTTP_PORT
          value: "3000"
          # The following env variables are required to make Grafana accessible via
          # the kubernetes api-server proxy. On production clusters, we recommend
          # removing these env variables, setup auth for grafana, and expose the grafana
          # service using a LoadBalancer or a public IP.
        - 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
          # If you're only using the API Server proxy, set this value instead:
          # value: /api/v1/namespaces/kube-system/services/monitoring-grafana/proxy
          value: /
      volumes:
      - name: ca-certificates
        hostPath:
          path: /etc/ssl/certs
      - name: grafana-storage
        emptyDir: {}
---
apiVersion: v1
kind: Service
metadata:
labels:
    # For use as a Cluster add-on (https://github.com/kubernetes/kubernetes/tree/master/cluster/addons)
    # If you are NOT using this as an addon, you should comment out this line.
    kubernetes.io/cluster-service: 'true'
    kubernetes.io/name: monitoring-grafana
name: monitoring-grafana
namespace: kube-system
spec:
# In a production setup, we recommend accessing Grafana through an external Loadbalancer
# or through a public IP.
# type: LoadBalancer
# You could also use NodePort to expose the service at a randomly-generated port
# type: NodePort
type: NodePort
ports:
- nodePort: 30108
    port: 80
    targetPort: 3000
selector:
    k8s-app: grafana