Avoid request limit for CDN connections in NGINX server

Question

I need to throttle connections/requests in NGINX server for both http and http2 requests. However, the throttling must not be applied to CDN specific IP addresses (which is already populated in geo block)

I have following config to throttle http/http2 requests when CDN specific requirement not in place.

map $http2 $http1connlimitkey {
    default "";
    ""  $binary_remote_addr;
}

map $http2 $http2connlimitkey {
    default $binary_remote_addr;
    "" "";
}

Either of http1connlimitkey and http2connlimitkey key is set to binary_remote_addr depending upon the type of connection.

Now irrespective of the connection type, if the connection is originated from CDN, I need to set the above keys to empty to escape the connection throttling.

I am following approach given in this solution How to rate-limit in nginx, but including/excluding certain IP addresses? to map the request origin.

geo $whitelist {
 default 0;
 # CIDR in the list below are not limited
 1.2.3.0/24 1;
 9.10.11.12/32 1;
}
map $whitelist $limit {
 0     $binary_remote_addr;
 1     "";
}

How do I set the http1connlimitkey and http2connlimitkey to empty if request is from CDN.

One of the way I am thinking is to have map like below

map $whitelist $cdn {
 0     ""
 1     "CDN";
}

map "$cdn$http2" $http1connlimitkey {
    "^CDN"  ""
    ""  $binary_remote_addr;
    default "";
}

map "$cdn$http2" $http2connlimitkey {
    "^CDN"  ""
    default $binary_remote_addr;
    "" "";
}

Any other better way to handle the same. I need to escape both http and http2 limits in case request in originated from CDN.

Thanks

Avoid request limit for CDN connections in NGINX server

0 Answers0