I believe you're using kubeadm to start your kubernetes cluster, you can generate the new kubeconfig file using following command:

kubeadm alpha phase kubeconfig admin --kubeconfig-dir /etc/kubernetes --cert-dir /etc/kubernetes/pki

This will generate a new config file in /etc/kubernetes/admin.conf. Then you can copy the file in following way:

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

Thanks to @PrafullLadha, there's a similar solution for OpenShift:

1. Install kubeadm with snap: sudo snap install kubeadm --classic

2. cd to your openshift cluster installation directory.

3. Make a copy of your TLS certificate: cp ./tls/journal-gatewayd.crt ./tls/ca.crt

4. Make a copy of your TLS key: cp ./tls/journal-gatewayd.key ./tls/ca.key

5. Run kubeadm as follow:

   kubeadm init phase kubeconfig admin --kubeconfig-dir ./auth --cert-dir "${PWD}/tls"

   It should output: [kubeconfig] Writing "admin.conf" kubeconfig file

6. vi ./auth/admin.conf - see that the certificates were added, and make sure the server address (https://api.your-cluster:6443) is correct.

7. Rename: mv ./auth/admin.conf ./auth/kubeconfig and you're all set.