kubectl get nodesで certificateエラー

[root@ip-172-31-34-51 ~]# kubectl get nodes
Unable to connect to the server: x509: certificate signed by unknown authority (possibly because of "crypto/rsa: verification error" while trying to verify candidate authority certificate "kubernetes")

$HOME/.kubeに有効な証明書がない。

https://kubernetes.io/ja/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm/

以下のコマンドを実行する

mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

unset KUBECONFIG
export KUBECONFIG=/etc/kubernetes/admin.conf