Selfhosted

As some have already mentioned info regarding security I wont add to that.

The other thing you should consider in my opinion is the legal side of things. Depending on you jurisdiction, you as the operator of the instance may be held accountable for the data it stores and serves. This means that you may be liable for both possession and distribution of illegal contents. I am not knowledgeable in regards to laws that cover moderation of content, but I assume you will be required to remove any such content if you gain knowledge of it. Again, this depends entirely on your countries laws and regulations but also on the laws and regulations of the countries you make your service available to.

Please be careful with hosting public instances. If anyone has more insight to this, please do add it and correct me if necessary.

If you are based in America, you will want to keep a close eye on the semi-regular attempts from congress to repeal Section 230 of the Communications Decency Act.

If it’s ever successfully repealed, you’d become liable for anything posted to your forum.

I just want to say that you should make sure to take notes on what you're doing and why. It helps when you break something and want to go through what you did and sometimes notes don't make sense unless you put why so you can research it again

The DMZ is the right idea. But it's the old way. You definitely want whatever is serving your website to be separated out from your house. You're hosting should be on an isolated VLAN. The internet should only be able to talk to the server it needs to talk to, no other ports. That box should only be allowed to talk to what it absolutely must talk to and only on the ports that are required. You should run an independent firewall on each one of the boxes that are involved in the hosting with only the proper ports open.

Giving up your private IP Will definitely give away your general location to everyone and your precise location to the authorities.

I would highly recommend using cloudflare or one of the other funnel options. A lot of people don't like cloud flare because they can capitalize on your traffic, The cloudflare also just won't shut you down and sell you out like your ISP will at the first request, They don't do shit about anything until there's a warrant or a court filing. On the upside you don't give out your private IP to anyone. You have DDOS protection, and a reasonable layer of anominity.

You need to check daily to make sure all of your software is updated. We're talking OS, middleware, plugins, application. Preferably via automation. All of the software and plugins you use for this type of hosting end up getting vulnerabilities.

Security is especially difficult on forums. There's lots of opportunities there for skilled people who are pissed off at what you or someone else is saying to get butthurt. People know exactly what you're running, then they do some magic behind the scenes next thing you know there's a bunch of admins you didn't create.

You don't need to be hosting your own email but you are going to need an SMTP provider, most free services won't let you masquerade the from address.

Don't do it.

Hosting a public service with no real knowledge of security can only end badly.

Get a vpc, do it there, learn from mistakes.

It's more than just HTTPS, you also need proper authentication, regular updates, emergency updates for critical vulnerabilities, ideally some sort of monitoring to detect potential misuse of the service or any escalations from the service to the OS.

Ask yourself this: If this was your first time driving a car, would you rather do it in an empty parking lot where at worst you will damage the car. Or would you rather do it in a busy street where at worst you can kill someone?

I would do it. Its fun...

Will you mess up? Yes. Who cares, Do it, just ensure its data you can lose no worries.

I would host on a vps, just to keep you home safe from swat raids (assuming you in the us, other nations should be safe).

just cloudflare tunnel it - i set one up the other day and it works super well, proving external access to a locally hosted service all without having to set up your own SsL certs and worrying about exposing private ips or ports

Hosting for yourself so you can access your content outside your home is usually the use-case, use WireGuard for that though (checkout headscale) along with virtualization, VLANs, etc.
Hosting for a group of friends and/or family can usually be ok, assuming that is a well known and restrict group.

Hosting for the general public from home is usually not recommended, use a VPS for that. Bear in mind you'll likely be liable for what you host, one way or the other, depending on your jurisdiction.
If you store content (files others may upload like movies and photos) you may be responsible for that (i.e. is that content legal in your jurisdiction?).
There may be a legal distinction between the server's geographic location and the entity responsible for it - but in your case it's the same, so, again, beware.
Just linking to content deemed illegal may get you into trouble.
Putting the site behind a login-only page and vetting account creation could mitigate (or exponentiate) this.
Anyway IANAL.

What do you want to host and for whom?

You might consider using something like Cloudflared or Tailscale's Funnels to proxy the connections through to prevent DDOSing and apply ACLs. You can still use your domains with those.

That's always a danger.

You could host the server on its own vlan and use tailscale to tunnel from a VPS to your server. This way your IP isn't exposed to the public. You can also add crowdsec or similar on the VPS.

I do the same thing with traefik on my dirt cheap VPS.

You don’t need to put the server in the DMZ, just port forward port 80 and 443. Most routers these days ignore all requests to ports that aren’t open. And stick it behind Cloudflare, so you don’t have to expose your IP. Cloudflare also allows you to generate SSL certs that are good for a decade.

I have dynamic dns through cloudflare that provides a proxy ip address for me in addition to some protections.

After that I use a reverse proxy to route specific domain names to services. My router is set up to forward only ports 80 and 443 to that reverse proxy, so there's a good layer of safety there. There could be a weakness on the router, but at this point traffic is pretty limited.

After that, at least for your service, if you can have some control or throttling of signings and be more selective about who you let in, then that could help.

I say do it. Sure there's risk someone could put something on there you don't want, but I wouldn't say it's big enough to not do it.

Try to automate updates as much as possible so that new security bugs get fixed quickly.

Do it.

There's really not much that can end badly, someone gets in your network (unlikely anyone even knows it exists)? reformat all your shit. Just by knowing what a DMZ is you are already more qualified than half the people I've met self hosting

do you run a business out of your house? do you run a bunch of peoples personal info? does anyone else? If you answered no to all of these then there really isn't much that can "go wrong" you can just unplug your shit.

hosting email also isn't that big of a deal but your home ISP will block port 25, you need to have a "business" one for them to unblock it and even then sometimes have to directly request it. Things like mailcow docker make it dead easy.

and yea as the other guy said always update your stuff

Well, obviously if you host from your home ISP, people will be able to figure out your home's approximate location via a reverse IP search.

But otherwise go for it. It's not that hard to do and a nice learning experience.