• Metrics-Server是集群核心监控数据的聚合器，用来替换之前的heapster。

• 容器相关的 Metrics 主要来自于 kubelet 内置的 cAdvisor 服务，有了Metrics-Server之后，用户就可以通过标准的 Kubernetes API 来访问到这些监控数据。

• Metrics API 只可以查询当前的度量数据，并不保存历史数据。

• Metrics API URI 为 /apis/metrics.k8s.io/，在 k8s.io/metrics 维护。

• 必须部署 metrics-server 才能使用该 API，metrics-server 通过调用 Kubelet Summary API 获取数据。

• Metrics Server 并不是 kube-apiserver 的一部分，而是通过 Aggregator 这种插件机制，在独立部署的情况下同 kube-apiserver 一起统一对外服务的。

• kube-aggregator 其实就是一个根据 URL 选择具体的 API 后端的代理服务器。
  
  上传镜像到仓库

部署后查看Metrics-server的Pod日志
kubectl

修改yaml文件 将443改为4443.镜像地址修改为自己的地址

• kubectl apply -f components.yaml
  

报错：x509: certificate signed by unknown authority
启用TLS Bootstrap 证书签发
解决：每个结点编辑文件，重启

vim /var/lib/kubelet/config.yaml 	
serverTLSBootstrap: true #在文件的最后一行加入

systemctl  restart kubelet重启

下边是因为我在其它节点多次重启上述文件，所以出现不止三个认证的问题，解决该问题只需要把所有没有通过认证的节点，通过认证即可

• kubectl get csr
• kubectl certificate approve csr-5hcdz

[root@server1 mnt]# kubectl get csr
NAME        AGE     SIGNERNAME                      REQUESTOR             CONDITION
csr-5hcdz   6m49s   kubernetes.io/kubelet-serving   system:node:server3   Pending
csr-74thb   8m54s   kubernetes.io/kubelet-serving   system:node:server2   Pending
csr-95vf8   11m     kubernetes.io/kubelet-serving   system:node:server1   Approved,Issued
csr-h9mm4   6m51s   kubernetes.io/kubelet-serving   system:node:server2   Pending
csr-jwsx5   23m     kubernetes.io/kubelet-serving   system:node:server2   Approved,Issued
csr-jzzrp   23m     kubernetes.io/kubelet-serving   system:node:server3   Approved,Issued
csr-wkjvw   8m50s   kubernetes.io/kubelet-serving   system:node:server3   Pending
csr-wpfw7   26m     kubernetes.io/kubelet-serving   system:node:server1   Approved,Issued
[root@server1 mnt]# kubectl certificate approve csr-5hcdz 
certificatesigningrequest.certificates.k8s.io/csr-5hcdz approved
[root@server1 mnt]# kubectl certificate approve csr-74thb
certificatesigningrequest.certificates.k8s.io/csr-74thb approved
[root@server1 mnt]# kubectl certificate approve csr-h9mm4
certificatesigningrequest.certificates.k8s.io/csr-h9mm4 approved
[root@server1 mnt]# kubectl certificate approve csr-wkjvw
certificatesigningrequest.certificates.k8s.io/csr-wkjvw approved
[root@server1 mnt]# kubectl get csr
NAME        AGE     SIGNERNAME                      REQUESTOR             CONDITION
csr-5hcdz   7m17s   kubernetes.io/kubelet-serving   system:node:server3   Approved,Issued
csr-74thb   9m22s   kubernetes.io/kubelet-serving   system:node:server2   Approved,Issued
csr-95vf8   11m     kubernetes.io/kubelet-serving   system:node:server1   Approved,Issued
csr-h9mm4   7m19s   kubernetes.io/kubelet-serving   system:node:server2   Approved,Issued
csr-jwsx5   24m     kubernetes.io/kubelet-serving   system:node:server2   Approved,Issued
csr-jzzrp   24m     kubernetes.io/kubelet-serving   system:node:server3   Approved,Issued
csr-wkjvw   9m18s   kubernetes.io/kubelet-serving   system:node:server3   Approved,Issued
csr-wpfw7   26m     kubernetes.io/kubelet-serving   system:node:server1   Approved,Issued

• kubectl -n kube-system get pod 查看是否ready
  

• kubectl top node

[root@server1 mnt]# kubectl top node
W0803 18:29:27.334697   15783 top_node.go:119] Using json format to get metrics. Next release will switch to protocol-buffers, switch early by passing --use-protocol-buffers flag
NAME      CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
server1   419m         20%    1233Mi          74%       
server2   329m         32%    661Mi           74%       
server3   116m         11%    606Mi           68%    

部署成功！