I have my config setup to handle a bunch of GET requests which render pixels that work fine to handle analytics and parse query strings for logging. With an additional third party data stream, I need to handle a POST request to a given url that has JSON in an expected loggable format inside of it's request body. I don't want to use a secondary server with proxy_pass and just want to log the whole response into an associated log file like what it does with GET requests. A snippet of some code that I'm using looks like the following:

GET request (which works great):
[code]
location ^~ /rl.gif {
set $rl_lcid $arg_lcid;
if ($http_cookie ~* "lcid=(.*\S)")
{
set $rl_lcid $cookie_lcid;
}

empty_gif;
log_format my_tracking '{ "guid" : "$rl_lcid", "data" : "$arg__rlcdnsegs" }';
access_log /mnt/logs/nginx/my.access.log my_tracking;
rewrite ^(.*)$ http://my/url?id=$cookie_lcid? redirect;
}
[/code]

Here is kinda what I am trying to do:
POST request (which does not work):
[code]
location /bk {
log_format bk_tracking $request_body;
access_log /mnt/logs/nginx/bk.access.log bk_tracking;
}
[/code]

Curling "curl http://myurl/bk -d name=example" gives me a 404 page not found.

Then I tried:
[code]
location /bk.gif {
empty_gif;
log_format bk_tracking $request_body;
access_log /mnt/logs/nginx/bk.access.log bk_tracking;
}
[/code]
Curling "curl http://myurl/bk.gif -d name=example" gives me a 405 Not Allowed.

My current version is nginx/0.7.62. Any help in the right direction is very much appreciated! Thanks!