Do you need a domain name if you are hosting a Lemmy instance, or will it work fine with just an ip-address + port (e.g. <username>@<ip-address>:<port>)?
It requires an HTTPS connection, and certificates can only be obtained for domain names. So yes, pretty much.
Also consider than IPs can change, even if you’re using a hosting provider. Domain names makes changing the IP much easier.
Domain names can be obtained for as cheap as $3/year for the xyz TLD. If you can’t pay for anything, there’s also free services that can let you get a subdomain, like noip.com, afraid.org, azote.org.
The reason being that federation means other instances send you things. It’s not pull-only, or else you could likely get away with private instances sitting behind NAT. But since activitypub involves publishing to inboxes from source to destination, they need some way to reach you. And since we want to validate that connection and that some external authority can vouch for ita ownership, we use TLS Certs with the DNS hostname that matches your server name.
certificates can only be obtained for domain names
That is not true, nothing prevents it on the technical side, and even some trusted CAs sell them under certain conditions
But wouldn’t that be the certificate of the other instance, not your local one?
Also if you dont mind numbers .xyz domains can be like $1 a year. It has to be only numbers and i think at least 9 digits.
Sorry but do you mean that .xyz domains only allow for a numbers only domain name? Because I don’t think that’s true.
No i mean if you want a super cheap .xyz domain, its very cheap if you choose a domain that is digits only. For example my lemmy domain is 158436977.xyz. its 89 cents a year.
You can certainly have xyz domains that are words just like any other.
I haven’t dug into the protocol, but I’d imagine communication would be done over HTTPS, which requires a domain.
I can’t imagine it’d work without a domain, as your instance will need to talk HTTPS with other instances.
it requires a name that can be addressed as https://sub.domain.name - otherwise it won’t allow https inbound.
SSL certificates for IP addresses are possible; but they require you to outright own the IP(-range). Some large organizations do. So for individuals it’s rather unheard of, but it’s technically achievable.
https://sectigostore.com/page/ssl-certificate-for-ip-address/
Well, I just learned something, but what does “control” the IP mean? If they are only validating a single address via http then presumably you could just use an Amazon elastic IP as long as it resolves. I doubt that letsencrypt will support that but I would be interested to know. If they do then yeah, you could presumably set up the instance using the IP as the name, but I don’t know why you would want to. Apart from the fact that it would be hard to remember, could change at some point, screwing things up, it might work. I suggest OP do the necessary and report back accordingly.
but what does “control” the IP mean
I believe that means you must be registered as the owner with the RIPE or whichever authority is in charge of administrating IP ranges, so that would also negate the point of chaining IP addresses, since that would indeed be a permanent fixture.
For AWS it should then only work if Amazon Inc. is the applicant for the SSL cert., not merely a user. So it’s a quite theoretical application at best.
