kubernetes之metrics-server安装与配置

一、metrics-server简介

从 Kubernetes 1.8 开始，资源使用指标（如容器 CPU 和内存使用率）通过 Metrics API 在 Kubernetes 中获取, metrics-server 替代了heapster。Metrics Server 实现了Resource Metrics API，Metrics Server 是集群范围资源使用数据的聚合器。 
Metrics Server 从每个节点上的 Kubelet 公开的 Summary API 中采集指标信息。

kubernetes metrics server 参考文档 https://github.com/kubernetes-incubator/metrics-server

二、安装metrics-server

会用到的yaml文件：

https://github.com/kubernetes-incubator/metrics-server/tree/master/deploy/1.8%2B 或者

https://github.com/kubernetes/kubernetes/tree/release-1.11/cluster/addons/metrics-server（建议使用）

下载六个文件并创建

for file in auth-delegator.yaml auth-reader.yaml metrics-apiservice.yaml metrics-server-deployment.yaml metrics-server-service.yaml resource-reader.yaml;do wget https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.11/cluster/addons/metrics-server/$file; done

需要修改的地方：

metrics-server-deployment.yaml #

- --source=kubernetes.summary_api:''

- --source=kubernetes.summary_api:https://kubernetes.default?kubeletHttps=true&kubeletPort=10250&insecure=true

resource-reader.yaml#

resources:

  - pods

  - nodes

   - namespaces

  - nodes/stats  #新加

开始运行： kubectl apply -f .

[root@master metrics]# kubectl api-versions

admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1 apps/v1beta1
apps/v1beta2 authentication.k8s.io/v1 
authentication.k8s.io/v1beta1 
authorization.k8s.io/v1 
authorization.k8s.io/v1beta1 
autoscaling/v1 
autoscaling/v2beta1 
batch/v1 
batch/v1beta1 
certificates.k8s.io/v1beta1 
crd.projectcalico.org/v1 
events.k8s.io/v1beta1 
extensions/v1beta1 
metrics.k8s.io/v1beta1 
#metrics控制器，有说明成功 
networking.k8s.io/v1 
policy/v1beta1 
rbac.authorization.k8s.io/v1 
rbac.authorization.k8s.io/v1beta1 
scheduling.k8s.io/v1beta1 
storage.k8s.io/v1 
storage.k8s.io/v1beta1 v1

查看pods

[root@master metrics]# kubectl get pods -n kube-system 
NAME                                    READY     STATUS    RESTARTS   AGE
coredns-78fcdf6894-cj6tn                1/1       Running   42         26d
coredns-78fcdf6894-wfvk8                1/1       Running   42         26d
elasticsearch-logging-0                 1/1       Running   45         4d
elasticsearch-logging-1                 1/1       Running   47         4d
etcd-master                             1/1       Running   42         26d
grafana-7f8bcdfbbf-qzln5                1/1       Running   4          13d
kibana-logging-7444956bf8-x8qqd         1/1       Running   2          4d
kube-apiserver-master                   1/1       Running   47         26d
kube-controller-manager-master          1/1       Running   43         26d
kube-flannel-ds-m4f4j                   1/1       Running   33         26d
kube-flannel-ds-xvssj                   1/1       Running   18         26d
kube-proxy-5lw6z                        1/1       Running   39         26d
kube-proxy-qlhg7                        1/1       Running   18         26d
kube-scheduler-master                   1/1       Running   39         26d
kubernetes-dashboard-767dc7d4d-4bt48    1/1       Running   5          5d
metrics-server-v0.2.1-84678c956-hbz2b   2/2       Running   0          2m

#这个状态是正常的

master新开一个反向代理端口

[root@master ~]# kubectl proxy --port=8080

Starting to serve on 127.0.0.1:8080

master新开一个窗口查看

[root@master ~]# curl http://localhost:8080/apis/metrics.k8s.io/v1beta1/nodes
{
  "kind": "NodeMetricsList",
  "apiVersion": "metrics.k8s.io/v1beta1",
  "metadata": {
    "selfLink": "/apis/metrics.k8s.io/v1beta1/nodes"
  },
  "items": [
    {
      "metadata": {
        "name": "master",
        "selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/master",
        "creationTimestamp": "2018-09-25T09:48:21Z"
      },
      "timestamp": "2018-09-25T09:48:00Z",
      "window": "1m0s",
      "usage": {
        "cpu": "211m",
        "memory": "2905388Ki"
      }
    },
    {
      "metadata": {
        "name": "node01",
        "selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/node01",
        "creationTimestamp": "2018-09-25T09:48:21Z"
      },
      "timestamp": "2018-09-25T09:48:00Z",
      "window": "1m0s",
      "usage": {
        "cpu": "150m",
        "memory": "3670276Ki"
      }
    }
  ]
}

三、测试是否安装成功

[root@master metrics]# kubectl top nodes

error: metrics not available yet

说明还未成功，需要等待一会

查看node

[root@master metrics]# kubectl top node
NAME      CPU(cores)   CPU%      MEMORY(bytes)   MEMORY%   
master    207m         10%       2832Mi          76%       
node01    144m         4%        3619Mi          37% 

查看pods

[root@master metrics]# kubectl top pods -n kube-system
NAME                                    CPU(cores)   MEMORY(bytes)   
coredns-78fcdf6894-cj6tn                2m           11Mi            
coredns-78fcdf6894-wfvk8                1m           11Mi            
elasticsearch-logging-0                 6m           1347Mi          
elasticsearch-logging-1                 6m           1326Mi          
etcd-master                             17m          84Mi            
grafana-7f8bcdfbbf-qzln5                0m           21Mi            
kibana-logging-7444956bf8-x8qqd         4m           83Mi            
kube-apiserver-master                   89m          486Mi           
kube-controller-manager-master          19m          59Mi            
kube-flannel-ds-m4f4j                   5m           14Mi            
kube-flannel-ds-xvssj                   5m           12Mi            
kube-proxy-5lw6z                        3m           15Mi            
kube-proxy-qlhg7                        3m           16Mi            
kube-scheduler-master                   6m           13Mi            
kubernetes-dashboard-767dc7d4d-4bt48    0m           11Mi            
metrics-server-v0.2.1-84678c956-hbz2b   1m           24Mi