I am using a rate liming based on ip address and below example work's perfectly for that.
http {
    limit_req_zone $binary_remote_addr zone=one:10m rate=1r/s;
    ...
    server {
        ...
        location /search/ {
            limit_req zone=one burst=5;
        }
Now we need to implement rate limiting based on apiid/apikey which will part of http request.Each api key will have restricted number of connections and when that goes beyond the restricted number i must give 503 or some thing like that.
How to get the apikey/apid from url into a variable and set a limit for each apikey we have ?
 
    