2. Renew client certificates

grep PATH ~/.bash_profile
source ~/.bash_profile
export ARCH="amd64"
export VERSION="v1.19.4"
curl -L -o /usr/local/bin/kubeadm https://dl.k8s.io/release/${VERSION}/bin/linux/${ARCH}/kubeadm

/usr/local/bin/kubeadm alpha certs renew apiserver-kubelet-client
/usr/local/bin/kubeadm alpha certs renew apiserver
/usr/local/bin/kubeadm alpha certs renew front-proxy-client
/usr/local/bin/kubeadm alpha kubeconfig user --client-name system:kube-controller-manager > /etc/kubernetes/controller-manager.conf
/usr/local/bin/kubeadm alpha kubeconfig user --client-name system:kube-scheduler > /etc/kubernetes/scheduler.conf

/usr/local/bin/kubeadm alpha kubeconfig user --client-name system:node:$(hostname) --org system:nodes > /etc/kubernetes/kubelet.conf
/usr/local/bin/kubeadm alpha kubeconfig user --client-name kubernetes-admin --org system:masters > /etc/kubernetes/admin.conf
cp -f /etc/kubernetes/admin.conf ~/.kube/config