Proxying module query

[Edward Hibbert]

I'm using the splendid guide to NGINX plugin modules, specifically the
upstream module part at
http://www.evanmiller.org/nginx-modules-guide.html#proxying . 

I'm struggling a bit to understand how a module can indicate which server to
issue a request to - the example proxy module code presumably does this via
the config for the upstream module.  If I'm just interested in sending a
query to a known host/port, what's the best way of doing this?  

I wondered if I could hijack the upstream module configuration to do it,
since I'm already using that in my  nginx.conf, but I've experimented with
trying to get a handle to the upstream module configuration from within my
module and I'm getting null back - so either I'm doing that wrong, or that's
not possible.

Alternatively I might need to take the code in ngx_http_upstream_init
request and simplify it a bit?  Unless any of you know of a simpler starting
point?
 
Thanks for any help you can offer,
 
Edward.