Regular expression from the hostname in the proxy_pass uri in Nginx
Solution 1:
Untested, but give this a shot:
server_name ~^(www\.)?[^.]+.example.org$;
if ($host ~* ^(www\.)?([^.]+).example.org$) {
set $subdomain $2;
}
location / {
proxy_pass http://example.org:8080/$subdomain;
}