iRule to intercept traffic and then send on to original pool

Just to follow up... finally got this working, this is the final iRule, which is a variation on the excellent ideas suggested in http://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/50/aft/14001/showtab/groupforums/Default.aspx.

 

 

when RULE_INIT {

 

set static::debug 1

 

}

 

 

when CLIENT_ACCEPTED {

 

if { $static::debug != 0 } {

 

log local0. "setting addingUser to 1"

 

}

 

set addingUser 1

 

}

 

 

when HTTP_REQUEST {

 

save original request

 

if { $addingUser == 1 } {

 

if { $static::debug != 0 } {

 

log local0. "saving request, redirecting to WebFarm"

 

}

 

set req [HTTP::request]

 

inject lookup URI in place of original request

 

HTTP::uri "/addDWUser"

 

set pool to webfarm pool

 

pool pool_WebFarm

 

}

 

}

 

 

when HTTP_RESPONSE {

 

if {$addingUser == 1 } {

 

collect first response (from lookup server) only

 

if {[HTTP::header exists Content-Length] && ([HTTP::header Content-Length] < 1048576) } {

 

set clength [HTTP::header Content-Length]

 

} else {

 

set clength 1048576

 

}

 

if { $static::debug != 0 } {

 

log local0. "collecting response presumably from WebFarm, length is $clength"

 

}

 

HTTP::collect $clength

 

}

 

}

 

 

when HTTP_RESPONSE_DATA {

 

Get poolname from server response

 

Response would ideally be in the form of a pool name only.

 

Otherwise parse or derive the poolname here

 

set myPool pool_DataWarehouse

 

verify pool exists and has members

 

if { ![catch [pool $myPool]] }{

 

if { $static::debug != 0 } {

 

log local0. "retrying request"

 

}

 

pool pool_DataWarehouse

 

HTTP::retry $req

 

} else {

 

 

insert dead/non-existent pool logic here

 

 

}

 

re-set flag so that subsequent response to re-tried

 

request from real server is not processed as a lookup

 

if { $static::debug != 0 } {

 

log local0. "setting addingUser to 0"

 

}

 

set addingUser 0

 

}

 

 

Thanks!

 

Jen