Nodes are not FQDN

General Discussions
1

When I deploy a kubernetes cluster and add hosts, I see that one of the host is picking up short name where as other hosts are picking up full name. Any suggestion for potential reasons for the same.

kubectl get nodes
NAME STATUS ROLES AGE VERSION
h01dn02.hadoop Ready worker 28h v1.18.6
h01dn03.hadoop Ready worker 6d11h v1.18.6
h01dn04.hadoop Ready worker 6d11h v1.18.6
h01dn05.hadoop Ready worker 6d11h v1.18.6
h01dn06 Ready worker 2d21h v1.18.6
h01dn08.hadoop Ready worker 6d11h v1.18.6
h01dn10.hadoop Ready master 39h v1.18.6
h01dn11.hadoop Ready master 39h v1.18.6
h01hn01.hadoop Ready master 6d11h v1.18.6

2

How did you deploy the node?

The node name comes from the kubelet on the node. If you use kubeadm for administration, there is a flag --node-name in kubeadm documentation that will set --hostname-override on the kublet.

Looking at the kubelet documentation, I see that this is how --hostname-override works:

If non-empty, will use this string as identification
instead of the actual hostname.

If `--cloud-provider` is set, the cloud provider
determines the name of the node (consult cloud
provider documentation to determine if and how
the hostname is used).