Kubernetes) Metrics server 오류_kubelet-insecure-tls

`kubelet-insecure-tls`

==================================
오류
==================================

$ k top node kube02
Error from server (ServiceUnavailable): the server is currently unable to handle the request (get nodes.metrics.k8s.io kube02)

==================================
상황 
==================================
$ k get nodes
NAME     STATUS   ROLES                         AGE   VERSION
kube01   Ready    control-plane,master,worker   70d   v1.20.4
kube02   Ready    worker                        66d   v1.20.4
kube03   Ready    worker                        66d   v1.20.4
kube04   Ready    worker                        66d   v1.20.4

$ k logs metrics-server-7d7847476c-r9p7c -n kube-system --follow
I1116 05:45:37.405482       1 serving.go:341] Generated self-signed cert (/tmp/apiserver.crt, /tmp/apiserver.key)
E1116 05:45:37.948151       1 scraper.go:139] "Failed to scrape node" err="Get \"https://1**.17.**2.88:10**0/stats/summary?only_cpu any IP SANs" node="kube03" 
E1116 05:45:37.952198       1 scraper.go:139] "Failed to scrape node" err="Get \"https://1**.17.**2.86:10**0/stats/summary?only_cpu any IP SANs" node="kube01" 

$ k describe metrics-server-7d7847476c-r9p7c -n kube-system

  Normal   Killing    59s                 kubelet            Container metrics-server failed liveness probe, will be restarted
  Normal   Created    58s (x2 over 117s)  kubelet            Created container metrics-server
  Normal   Started    58s (x2 over 117s)  kubelet            Started container metrics-server
  Warning  Unhealthy  19s (x5 over 99s)   kubelet            Liveness probe failed: HTTP probe failed with statuscode: 500
  Warning  Unhealthy  16s (x6 over 116s)  kubelet            Readiness probe failed: HTTP probe failed with statuscode: 500

==================================
수정
==================================
$ k edit deploy -n kube-system  metrics-server
args:
   - --kubelet-insecure-tls

==================================
해결
==================================
$ k top node kube02
NAME     CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
kube02   322m         4%     10305Mi         34%

참고
- https://github.com/kubernetes-sigs/metrics-server/issues/614