Dynamically selecting a class (based on poolname)

Hi,

Is it possible to dynamically select a class? I want to use one class per pool which lists a cookie per server and select that server based on the cookie. Using passive cookies is not an option since I cannot change the cookie-values on the server. Of course I can write an iRule per virtual server, but it would be nicer to have a general one that is able to select the appropriate class.

It would be something like this:

rule prefCookie-iRule {
   when CLIENT_ACCEPTED {
      set defpool [LB::server pool]
      log local0. "defpool selected for -> $defpool"
   }
   when HTTP_REQUEST {
     if { [HTTP::cookie exists "lbsid"] } {
        set tmp [findclass [HTTP::cookie "lbsid"] ::$defpool " "]
        if { $tmp ne "" } {
           log local0. $tmp              
           node $tmp
        } else {
           log local0. "[HTTP::cookie "lbsid"] is not a valid cookie-value!"
           pool $defpool
        }
     } else {
        log local0. "No lbsid cookie found!"
        pool $defpool
     }
   }
   when LB_FAILED {
      log local0. "LB failed, so chose a new member!"
      pool $defpool
      LB::reselect
   }
}

The problem is that the line 'set tmp [findclass [HTTP::cookie "lbsid"] ::$defpool " "]' does not work, it looks like this line is interpreted __before__ $defpool is set. How can I solve this? I guess I need a command that has a class as output and a string as input, but is there anything capable of doing that?

Cheers, Sake