I have a system where many (~20k) subdomains use nginx's default_server, which passes the work off to an app.
I also have many (~100) hostnames that need to be redirected to a correct one, that is different for each hostname and that would then redirect to the default_server.
one.example.com -> eleven.example.com
two.example.com -> twelve.domain.com
three.example.com -> wibble.example.com
blah.domain.com -> fifteen.example.com
The redirects are arbitrary, ie there is no pattern to them.
Rather than having to update nginx config to add a new server block whenever a new redirect is needed or updated I'd prefer to use a map file of some sort that nginx can check for redirects.
Sadly having searched about quite a bit I've not found anything like it, all examples I've found use a new server block for each redirecting host or use regexes. I'd prefer to be able to update a map file or database on the fly that nginx can refer to.
My current best option I have is to update the background app to apply the redirects.