> I figure the trickiest part will be building those requests and getting
> them in to state that's usable by nginx.

This is already done, so there isn't much to figure out ;)

Just create "independent" request:
r = ngx_supervisord_init(pool, uscf);
and then you can inject it into regular nginx's flow:
ngx_http_upstream_init(r);

You just need to create your own u->peer.get(), u->peer.free(),
u->create_request() and u->finalize_request() functions.

That's of course, if you give up on subrequests.

Best regards,
Piotr Sikora < piotr.sikora@frickle.com >