部署k8s监控(2.2)：安装metrics-server，解决dashboard-2.0.1中无法查看内存、cpu等资源的问题

下载metrics-server的yaml文件

解决上章遗留的问题：无法监控内存和cpu资源
转接上文：部署k8s监控(3):dashboard-2.0.1

一、创建用户，并生成证书

	[root@k8s-master1 /]# useradd aggregator
	[root@k8s-master1 aggregator]# vim ./metrics-server-csr.json 
		{
		  "CN": "aggregator",
		  "hosts": [],
		  "key": {
		    "algo": "rsa",
		    "size": 2048
		  },
		  "names": [
		    {
		      "C": "CN",
		      "ST": "BeiJing",
		      "L": "BeiJing",
		      "O": "k8s",
		      "OU": "System"
		    }
		  ]
		}
	#生成证书
	[root@k8s-master1 aggregator]# cfssl gencert \
		-ca=/opt/kubernetes/ssl/ca.pem \
		-ca-key=/opt/kubernetes/ssl/ca-csr.json  \
		-ca-key=/opt/kubernetes/ssl/ca-key.pem \
		-profile=kubernetes metrics-server-csr.json | cfssljson -bare metrics-server
	#查看生成的证书
	[root@k8s-master1 aggregator]# ls
		metrics-server.csr  metrics-server-csr.json  metrics-server-key.pem  metrics-server.pem

二、开启聚合层

	[root@k8s-master1 /]# vim /opt/kubernetes/cfg/kube-apiserver
		--requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \
		--requestheader-allowed-names=aggregator \
		--requestheader-extra-headers-prefix=X-Remote-Extra- \
		--requestheader-group-headers=X-Remote-Group \
		--requestheader-username-headers=X-Remote-User \
		--proxy-client-cert-file=/home/aggregator/metrics-server.pem \
		--proxy-client-key-file=/home/aggregator/metrics-server-key.pem"
	如果报以下错误说明没有修改metrics-server-deployment.yaml文件，同时也需要coredns的参与
		E0526 16:44:18.091548       1 manager.go:102] unable to fully collect metrics: [unable to fully scrape metrics from source kubelet_summary:node1: unable to fetch metrics from Kubelet node1 (node1): Get http://node1:10250/stats/summary/: dial tcp: lookup node1 on 10.0.0.2:53: server misbehaving, unable to fully scrape metrics from source kubelet_summary:master1: unable to fetch metrics from Kubelet master1 (master1): Get http://master1:10250/stats/summary/: dial tcp: lookup master1 on 10.0.0.2:53: server misbehaving, unable to fully scrape metrics from source kubelet_summary:node2: unable to fetch metrics from Kubelet node2 (node2): Get http://node2:10250/stats/summary/: dial tcp: lookup node2 on 10.0.0.2:53: server misbehaving]
	#修改文件
	[root@k8s-master1 /]# vim /root/metrics/metrics-server-deployment.yaml 
		    spec:
	      priorityClassName: system-cluster-critical
	      serviceAccountName: metrics-server
	      containers:
	      - name: metrics-server
	        image: k8s.gcr.io/metrics-server-amd64:v0.3.1
	        command:
	        - /metrics-server
	        - --kubelet-insecure-tls			#添加
	        #- --metric-resolution=30s			#注释
	        - --kubelet-preferred-address-types=InternalIP   #添加
	        # These are needed for GKE, which doesn't support secure communication yet.
	        # Remove these lines for non-GKE clusters, and when GKE supports token-based auth.
	        #- --kubelet-port=10255 			#注释，让他使用10250
	        #- --deprecated-kubelet-completely-insecure=true 	#注释
	——————————————————————————————————————————————————————

		        volumeMounts:
	        - name: metrics-server-config-volume
	          mountPath: /etc/config
	        command:			#修改以下带有环境变量的值
	          - /pod_nanny
	          - --config-dir=/etc/config
	          - --cpu=100m
	          - --extra-cpu=0.5m
	          - --memory=100Mi
	          - --extra-memory=10Mi
	          - --threshold=5
	          - --deployment=metrics-server-v0.3.1
	          - --container=metrics-server
	          - --poll-period=300000
	          - --estimator=exponential
	          # Specifies the smallest cluster (defined in number of nodes)
	          # resources will be scaled to.
	          #- --minClusterSize={{ metrics_server_min_cluster_size }}
	      volumes:

	[root@k8s-master1 /]# vim /root/metrics/resource-reader.yaml 
	    resources:
		  - pods
		  - nodes
		  - namespaces
		  - nodes/stats		#添加
		  verbs:

三、生成apiservice

	[root@k8s-master1 /]# kubectl apply -f /root/metrics/
	[root@k8s-master1 /]# kubectl  get apiservice
		v1beta1.metrics.k8s.io                 kube-system/metrics-server   True        54m
	#查看是否配置成功
	[root@k8s-master1 /]# kubectl top nodes
		NAME      CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
		master1   110m         5%     849Mi           45%       
		node1     62m          3%     873Mi           46%       
		node2     53m          2%     583Mi           30%  

四、查看web界面