Is it mandatory to set hostname 'k8s-master' for master node in kubernetes? Can we change IP address of the master node and child node after successful installation of kubernetes?
In general, master node name composed from hostname of the machine where you bootstrap Kubernetes cluster, moreover master node name can be changed via building cluster procedure through kubeadm install tool:
kubeadm init --node-name.
Solution provided by @valerius257 for Kubernetes master node IP replacement in a comment from @char works pretty fine, that was already checked in my environment. Answer retains for any further contributors research.