iRule - Adding a cookie based on Geo-IP , without breaking everything

Are your URLs prefixed with "/usa" or just "/usa"? You may want to use starts_with instead of equals in your if statement if that's the case.

Also, I would use

HTTP::cookie replace

instead of

insert

because it will replace an existing cookie and only insert it if there isn't already one. And I don't think you'd need the domain and path on the request insert.

I think you have a syntax error in your

HTTP_RESPONSE

event too. If the variable is not initialized to anything, then in when you check it, it will be undefined and a TCL error will occur. Because of that, you'll need to use the

[info exists varname]

. That may help.

Here's an updated iRule to try

when HTTP_REQUEST {
    if { [string tolower "[HTTP::host][HTTP::uri]"] starts_with "mywebsite.com/usa" } {            
         Parse the client IP from the header supplied
        if { [HTTP::header exists "X-Forwarded-For"] } {
            log local0. " Staging - XFF ... incoming connection from $client_ip"
            set client_ip [HTTP::header value "X-Forwarded-For"]
        } else {
            log local0. "Staging - XFF Header was empty so using actual IP - $client_ip"
            set client_ip [IP::client_addr]
        }

        set state [string tolower [whereis $client_ip state]]
        log local0. " Staging - incoming connection from $client_ip detected state as $state"
        if { $state eq "florida" } {
            log local0. " Staging -  .. $state.. "
            set cookie_insertion 1

             I would use 'replace' instead of insert so it'll only keep a single cookie instead of adding an additional one
            HTTP::cookie replace name "uslocation" value $state 
        }

        log local0. "Cookies = [HTTP::cookie uslocation] "
    } else {
        pool POOL-STAGING-HTTP
    }
}

when HTTP_RESPONSE {
    if { [info exists cookie_insertion] && $cookie_insertion > 0 }{
        log local0. " RESPONSE - Adding cookie to response Staging - ... $state.. "
        HTTP::cookie insert name "uslocation" value $state path "/usa"  domain "mywebsite.com" 
        log local0. "RESPONSE - Cookies = [HTTP::cookie uslocation] " }
    }
}