Is there some sort of how to forum/guide on setting up a hosted versions of open-source projects? Googling this specific thing is quite difficult. A good alternative to setting up my own hosted service is for me to be able to ask DO to charge a $2/10 pm premium via my DO deploy buttons instead. I have sent thousands of clicks their way of which i see $0 via basic referrals. One can dream!
Each service has it's own requirements so it's hard to make a generalised guide. Unless you're talking about fundamentals of running a linux vm that's exposed to the internet? There are guides on aspects of that, though I've yet to find anything really good in that area.
BIND, NGINX, Postfix, Apache... they all have excellent documentation on setup and securing.
I'm curious which aspect your seeing as poorly documented. Perhaps some specificity would help others point you at a reference.
I mean how does discourse itself provide the discourse-hosted version (https://www.discourse.org/pricing)?
Do they spool up a new instance via K8S? Do they use terraform every time someone signs up? How do they manage one paid user wanting to run multiple discourses? There should be a guide for this, it would make a lot of OSS maintainers' lives much easier.