1、浅析整个监控流程
heapster以k8s内置的cAdvisor作为数据源收集集群信息,并汇总出有价值的性能数据(Metrics):cpu、内存、网络流量等,然后将这些数据输出到外部存储,如InfluxDB,最后就可以通过相应的UI界面显示出来,如grafana。 另外heapster的数据源和外部存储都是可插拔的,所以可以很灵活的组建出很多监控方案,如:Heapster+ElasticSearch+Kibana等等。
2、创建k8s资源对象
使用官方提供的yml文件有一些小问题,请参考以下改动和说明:
2.1、创建InfluxDB资源对象
apiVersion: apps/v1
kind: Deployment
metadata:
name: monitoring-influxdb
namespace: kube-system
spec:
replicas: 1
selector:
matchLabels:
task: monitoring
k8s-app: influxdb
template:
metadata:
labels:
task: monitoring
k8s-app: influxdb
spec:
containers:
- name: influxdb
image: k8s.gcr.io/heapster-influxdb-amd64:v1.3.3
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:
type: NodePort
ports:
- nodePort: 31001
port: 8086
targetPort: 8086
selector:
k8s-app: influxdb
注意:这里我们使用NotePort暴露monitoring-influxdb服务在主机的31001端口上,那么InfluxDB服务端的地址:http://[host-ip]:31001 ,记下这个地址,以便创建heapster和为grafana配置数据源时,可以直接使用。
2.1、创建Grafana资源对象
apiVersion: apps/v1
kind: Deployment
metadata:
name: monitoring-grafana
namespace: kube-system
spec:
replicas: 1
selector:
matchLabels:
task: monitoring
k8s-app: grafana
template:
metadata:
labels:
task: monitoring
k8s-app: grafana
spec:
containers:
- name: grafana
image: k8s.gcr.io/heapster-grafana-amd64:v4.4.3
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
ports:
- nodePort: 30108
port: 80
targetPort: 3000
selector:
k8s-app: grafana
注意:这里我们使用NotePort暴露monitoring-grafana服务在主机的30108上,那么Grafana服务端的地址:http://registry.wuling.com:30108 ,通过浏览器访问,为Grafana修改数据源,如下:
标红的地方,为上一步记录下的InfluxDB服务端的地址。
2.2、创建Heapster资源对象
apiVersion: v1
kind: ServiceAccount
metadata:
name: heapster
namespace: kube-system
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: heapster
namespace: kube-system
spec:
replicas: 1
selector:
matchLabels:
task: monitoring
k8s-app: heapster
template:
metadata:
labels:
task: monitoring
k8s-app: heapster
spec:
serviceAccountName: heapster
containers:
- name: heapster
image: k8s.gcr.io/heapster-amd64:v1.4.2
imagePullPolicy: IfNotPresent
command:
- /heapster
- --source=kubernetes:https://kubernetes.default
- --sink=influxdb:http://150.109.39.33:31001 # 这里填写刚刚记录下的InfluxDB服务端的地址。
---
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
--source 为heapster指定获取集群信息的数据源。参考:https://github.com/kubernetes/heapster/blob/master/docs/source-configuration.md
--sink 为heaster指定后端存储,这里我们使用InfluxDB,其他的,请参考:https://github.com/kubernetes/heapster/blob/master/docs/sink-owners.md
这里heapster留下了一个的坑,请继续往下看,当我部署完heapster,通过查看Heapster容器组的镜像发现:
很多人都以为是https或者k8s配置的问题,于是去就慌忙的去配置InSecure http方式,导致坑越来越深,透明度越来越低,更是无从下手,我也是这样弄了很久,都较上劲了,此处省略一万字。。。,当这些路子都走遍了,再次品读下面的原文:
才发现是权限的问题,heaster默认使用一个令牌(Token)与ApiServer进行认证,通过查看heapster.yml发现 serviceAccountName: heapster ,现在明白了吧,就是heaster没有权限,那么如何授权呢-----给heaster绑定一个有权限的角色就行了,如下:
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: heapster
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: heapster
namespace: kube-system
当创建heapster资源的时候,直接把这段代码加上,就行了。
3、查看监控详情
3.1、通过dashboard查看集群概况
整个监控方案部署成功后,从上图可以看到,在不同粒度/维度下,dashboard上可以呈现对象的具体CPU和内存使用率。