# Step 1): Backup old certs and kubeconfigs
mkdir /etc/kubernetes.bak
cp -r /etc/kubernetes/pki/ /etc/kubernetes.bak
cp /etc/kubernetes/*.conf /etc/kubernetes.bak
# Step 2): Renew all certs
kubeadm alpha certs renew all --config kubeadm.yaml
# Step 3): Renew all kubeconfigs
kubeadm alpha kubeconfig user --client-name=admin
kubeadm alpha kubeconfig user --org system:masters --client-name kubernetes-admin > /etc/kubernetes/admin.conf
kubeadm alpha kubeconfig user --client-name system:kube-controller-manager > /etc/kubernetes/controller-manager.conf
kubeadm alpha kubeconfig user --org system:nodes --client-name system:node:$(hostname) > /etc/kubernetes/kubelet.conf
kubeadm alpha kubeconfig user --client-name system:kube-scheduler > /etc/kubernetes/scheduler.conf
# Another way to renew kubeconfigs
# kubeadm init phase kubeconfig all --config kubeadm.yaml
# Step 4): Copy certs/kubeconfigs and restart Kubernetes services