kube-error-upgrade-connection

kube-error-upgrade-connection

Cannot connect to any pod - get "Unable to upgrade connection".

Log:
Apr  2 03:42:59 graphit kubelet[18632]: E0402 03:42:59.173155   18632 server.go:253] Unable to authenticate the request due to an error: x509: certificate has expired or is not yet valid

Meanwhile:

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Apr 02, 2023 00:29 UTC   364d                                    no      
apiserver                  Apr 02, 2023 00:29 UTC   364d            ca                      no      
apiserver-etcd-client      Apr 02, 2023 00:29 UTC   364d            etcd-ca                 no      
apiserver-kubelet-client   Apr 02, 2023 00:29 UTC   364d            ca                      no      
controller-manager.conf    Apr 02, 2023 00:29 UTC   364d                                    no      
etcd-healthcheck-client    Apr 02, 2023 00:29 UTC   364d            etcd-ca                 no      
etcd-peer                  Apr 02, 2023 00:29 UTC   364d            etcd-ca                 no      
etcd-server                Apr 02, 2023 00:29 UTC   364d            etcd-ca                 no      
front-proxy-client         Apr 02, 2023 00:29 UTC   364d            front-proxy-ca          no      
scheduler.conf             Apr 02, 2023 00:29 UTC   364d                                    no      

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Mar 01, 2030 13:36 UTC   7y              no      
etcd-ca                 Mar 01, 2030 13:36 UTC   7y              no      
front-proxy-ca          Mar 01, 2030 13:36 UTC   7y              no      

On the node:

root@cn07:~# openssl x509 -in /etc/kubernetes/pki/ca.crt -text
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 0 (0x0)
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: CN = kubernetes
        Validity
            Not Before: Mar  3 13:36:01 2020 GMT
            Not After : Mar  1 13:36:01 2030 GMT
        Subject: CN = kubernetes
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
...

# kubectl version
Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.5", GitCommit:"e6503f8d8f769ace2f338794c914a96fc335df0f", GitTreeState:"clean", BuildDate:"2020
-06-26T03:47:41Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.3", GitCommit:"06ad960bfd03b39c8310aaf92d1e7c12ce618213", GitTreeState:"clean", BuildDate:"2020
-02-11T18:07:13Z", GoVersion:"go1.13.6", Compiler:"gc", Platform:"linux/amd64"}