Kubernetes 在部署 metrics-server 的时候报错

在 kubernetes 1.18.20 集群上部署 Metrics-Server 的时候出现了如下的错误：

E1120 04:38:00.531458       1 scraper.go:139] "Failed to scrape node" err="Get \"https://110.128.134.114:10250/stats/summary?only_cpu_and_memory=true\": x509: cannot validate certificate for 110.128.34.114 because it doesn't contain any IP SANs" node="www.datang001.com"
E1120 04:38:00.561295       1 scraper.go:139] "Failed to scrape node" err="Get \"https://110.128.134.116:10250/stats/summary?only_cpu_and_memory=true\": x509: cannot validate certificate for 110.128.34.116 because it doesn't contain any IP SANs" node="www.datang002.com"
E1120 04:38:00.567535       1 scraper.go:139] "Failed to scrape node" err="Get \"https://110.128.134.115:10250/stats/summary?only_cpu_and_memory=true\": x509: cannot validate certificate for 110.128.34.115 because it doesn't contain any IP SANs" node="www.datang003.com"
E1120 04:38:00.580040       1 scraper.go:139] "Failed to scrape node" err="Get \"https://110.147.207.181:10250/stats/summary?only_cpu_and_memory=true\": x509: cannot validate certificate for 110.147.207.181 because it doesn't contain any IP SANs" node="www.datang004.com"
I1120 04:38:04.324529       1 server.go:188] "Failed probe" probe="metric-storage-ready" err="not metrics to serve"

根据我的 kubernetes 的版本，我选择的是 Metrics-Server 的 v0.5.2 版本，之所以出现上述的报错信息，是因为 kubelet 的10250端口使用的是 https 协议，连接需要验 tls 的客户端证书，我们应该在配置文件 components.yaml 添加 - --kubelet-insecure-tls参数后，就不需要验证客户端证书了。

...
...
spec:
      containers:
      - args:
        - --cert-dir=/tmp
        - --secure-port=4443
        - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
        - --kubelet-use-node-status-port
        - --metric-resolution=15s
        - --kubelet-insecure-tls
        image: k8s.gcr.io/metrics-server/metrics-server:v0.5.2
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
...
...

修改之后，再次查看各个 node 节点的 cpu 和 memory 使用情况：

[[e-mail] metrics-server]$ kubectl top node
NAME              CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
www.datang001.com   946m         23%    8569Mi          54%
www.datang002.com   645m         16%    10149Mi         64%
www.datang003.com   627m         15%    12534Mi         79%
www.datang004.com   902m         5%     17756Mi         13%
www.datang005.com   2066m        8%     57763Mi         44%
www.datang006.com   513m         2%     14375Mi         11%

查看单个 Pod 的使用情况:

[[e-mail] metrics-server]$ kubectl top pod  kube-proxy-sgwfh -n kube-system
NAME               CPU(cores)   MEMORY(bytes)
kube-proxy-sgwfh   1m           22Mi