I’m interested in setting up my own instances for Lemmy, Mastodon, and Matrix.
Can I use the same https://domain.tld for all of them without any subdomains?
For example:
lemmyuser@mydomain.tld
mastodonuser@mydomain.tld
matrixuser@mydomain.tld
Will this work across all of my self-hosted instances, or do I need to append a subdomain for each, e.g., lemmyuser@lemmy.mydomain.tld?
All those services use a protocol named WebFinger that allows for having the servers in different domains but showing the users as being in a main domain. For example, my self-hosted Synapse server is at matrix.domain.tld, but my users are all like user@domain.tld.
Unfortunately I don’t really know how to set it all up manually, I just let Yumohost take care of managing it.
Matrix (or even easier XMPP) can coexist on the same domain with Lemmy or Mastodon, but with two ActivityPub services that is AFAIK not possible.
Regardless of configuration, you still need to access the instance from mastodon.mydomain.tld or lemmy.mydomain.tld, but you can configure the Mastodon to use @mastodonuser@mydomain.tld as its identifier by setting
WEB_DOMAINtomydomain.tld.Mastodon documentation on the topic: https://docs.joinmastodon.org/admin/config/#web_domain
