Hi, you no need any FQDN or DNS entries ror this example, you need to setup the hostname you want and add it to the /etc/hosts onall nodes, for example mini master 1 node have:

root@kube-master1:~# cat /etc/hosts
127.0.0.1       localhost
xx.xx.xx.xx kube-master1
root@kube-worker2:~# cat /etc/hosts
127.0.0.1       localhost
xx.xx.xx.xx kube-worker2

Do same on all your nodes, then the kubeadm will take the hostnames when it’ll create cluster.

After all you will get something like this:

root@kubectl:~# kubectl get no 
NAME           STATUS   ROLES    AGE   VERSION
kube-master1   Ready    master   70d   v1.13.1
kube-master2   Ready    master   70d   v1.13.1
kube-worker1   Ready    <none>   70d   v1.13.1
kube-worker2   Ready    <none>   70d   v1.13.1
kube-worker3   Ready    <none>   70d   v1.13.1

You no need any local DNS for this cluster, kubernetes will have own dns inside, after cluster be created.