This is more of request for improvement than a bug report.

Version:

$ openshift-install version
4.10.X

Platform:

none (SNO)

Please specify:

• UPI (semi-manual installation on customized infrastructure)

What happened?

Deployed SNO on a VM and tried taking it to an OpenStack environment, the fully qualified name was kept but the IP of the node changed.

After some digging it was found that some configuration for the etcd static pod had the original VM IP address written instead of using the hostname of the node.

The worse probably was finding out that even the TLS certificates list the IP address as alternate DNS.

Some files were easily fixed (grep/sed) but the certificate and some OpenShift components like openshift-apiserver are a different matter.

The current documentation literally says:

"Without persistent IP addresses, communications between the apiserver and etcd might fail."

Based on my observations, I don't find that accurate, unless I'm missing something.

Given that RHCOS relies on the DNS and therefore, it's a deployment requirement, it would make sense, and ease some use cases, to use the hostname instead of the IP address.

What did you expect to happen?

The DNS hostname to be used for configuration instead of the IP address.

How to reproduce it (as minimally and precisely as possible)?

Deploy SNO and change its IP address after a successful installation.