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.