I'm playing about getting Virtualmin setup on an Amazon Lightsail Ubuntu instance and I have run Webmin/Virtualmin instances on Amazon EC2 Ubuntu instances in the past.
It would seem that almost all the recent Virtualmin setup guides and videos out there (from DigitalOcean and the like...) mention the prerequisite of setting up custom nameservers (e.g. ns1.yourdomain.tld, ns2.yourdomain.tld) and then proceed with setting the hostname and FQDN on the instance. I have set the hostname and FQDN on instances in the past without too much trouble (granted it seemed to grind Lightsail instances to a halt?!) but reading up on establishing custom nameservers is just a minefield of conflicting and outdated information.
I'm having a hard time understanding one, why custom nameservers are needed and two, what exactly defines a custom nameserver. Are they 2 x A records pointed at the static IP of the instance... are they GLUE records that need to be setup with the registrar... are they aliases pointing to the Lightsail / EC2 nameservers?
To explain what I will be running on this particular instance: 1 single Wordpress website, 1 primary and 2 additional domains pointed at it (all resolving to the primary domain), 2 or 3 email mailboxes for the primary domain (undecided on config but likely send / receive via IMAP). Will the likes of this be dependent on getting custom nameservers in place?
Thanks in advance folks and apologies for the noob question