Proxy Pass based on the first field in the URI

[j94305]

PS: If, like you mentioned in the other reply message, want to create
environments dynamically, you could use the map directive with an include
file that is dynamically updated by the deployment process of such an
environment (and then do nginx -s reload), but even more elegant would be
the replacement of the (static) map by a (dynamic) keyval map. The keyval
mappings can be maintained via the NGINX API, so you won't need reloads of
NGINX in the event of updates. The use of the keyval map is identical to the
map directive, except the definition would use a keyval zone.

Cheers,
--j.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,285607,285623#msg-285623