Here is a play for installing Discourse. The idea is to write out and discuss each point, so we can give a deeper look as to why we are doing it this way.
Ref: Discourse installation notes, steps i took to spin up a new discourse instance at forum.mycelium.garden on digitalocean - #12 by judytuna
Discuss when needed, edit when needed, be bold. 
Having multiple points of view will make the playbook stronger, so I’m glad I’ve taken a crack at it twice now too! Go team!
We get a fair amount of questions in the meta.discourse about domains, such as: do folks need a domain to run Discourse?
The is answer is: most likely. There are some hosting platforms that give out instances on sub-domains, but they install it for you. This is a self-hosted Discourse playbook, so the answer is yeah, you’ll need a domain.
You can use an existing domain, of course, and makes perfect sense given Discourse adds forums to a domain, which can be used for other purposes.
The popular advice is to use a sub-domain. Note: we need to seek out examples of advice given.
Reasons to not use a bare domain (talkgroup.xyz):
I didn’t want to use talkgroup.xyz for anything else, but even if I had, don’t think I’d have a problem switching it to a sub-domain. The reasons for caring appear to be search-engine related, of limited value.
CDNs, specifically “pull zones” are implemented by creating a CNAME record for the resource serving the zone. Bare domains (sans the sub-part) don’t have a standardized way of accepting CNAME records, and there are several reasons this can cause issues, and implementations are done by large players like Cloudflare, which is not the direction we want to go; we want standards.
This is complicated by the HTTPS issue, as the common sense decision is to go in with Let’s Encrypt. It seems tangential, but these technologies and dependencies are being used to pump out a lot of profit, hence so much support and practical requirements.
In Discourse a CDN can be used in two ways: to serve assets (uploads, for instance), or the entire site. In talkgroup we use a CDN solely for uploads, and not for bandwidth issues but for storage reasons: we upload a bunch and I don’t want to worry about it on the VPS. I push uploads into a blob storage bucket, and point the CDN there.
It looks like:
It’s been noted that talkgroup uses more resources than necessary, but my blob storage (DigitalOcean Spaces) is pooled with the account, on which I use many servers, so the cost is folded in the overall account.
My personal experience indicates assets are the bottleneck, and full-site acceleration is of limited use given the nature of most forums. I also like bare domains and single-use domains. That’s why I set up talkgroup like this.
I have some more thoughts on this…
this is v. helpful. thank you!