I have personally known abusers that are so charming and considerate and kind outside of the home that it makes the abused person question reality, and trying to talk about it to people they know feel impossible.
R Pike is legend. His videos on concurrent programming remain reference level excellence years after publication. Just a great teacher as well as brilliant theoretical programmer.
Actually, wait. Something you a said might actually be just what I'm looking for: you mean that I can have DNS entry for mydomain.com and no additional CNAMEs, and have a cert for nextcloud.mydomain.com (or wildcard maybe?) and somehow still be able to use name based virtual servers?
Hmmm. I thought I was going to be limited to path-based.
Okay. Yup, that's probably true. I'm not that deep into network stuff. But, if you're just doing the basic, 'ha.mydomain.com => 121.41.38.9' that works out of the box with name based virtual hosts and reverse proxy, then yeah, you'll get traffic on that within 24 hours.
I reckon if a person understands what you're talking about though, they're already doing better than most.
It trivial to get a list of all registered domains and subdomains and the IP addresses they map to. There are any number of paid services to make it easy (e.g. https://subdomainfinder.c99.nl/) but I'm pretty sure there's also a way to do it yourself.
Worth noting about this approach is that the global list of subdomains is publicly searchable. So, you'll see vulnerability and AI scans on those endpoints.
If that's a concern for you, using path-based routing (e.g. Apache VirtualHost) allows you to use difficult to guess paths to your cloud.
It's not hard. I've worked in education, grant management, county government, online retail (that one was marginally not evil), and a bunch of others. You just have to know when to say yes and when to say no.
As expected, it doesn't show up. I had a couple of other subdomains configured before I switched to wildcard, but nothing matches the random one