Forum Discussion

raj_77723's avatar
raj_77723
Icon for Nimbostratus rankNimbostratus
Feb 14, 2016

Custom iRule for URL rewrite for specific pool members

Requirement is   Virtual mapped with pool of 10 App servers. out of 10, 7 servers running with old version and 3 servers with new version. but the URL differs with server version. client will be ...
application delivery
iRules
LTM
Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Feb 15, 2016

Hi Raj,

you may take a look to the snippet below...

It compares the currently selected node with the output of 

[members -list YOUR_NEW_APP_POOL]
(where the pool YOUR_NEW_APP_POOL contains just the new application servers). If the currently selected member can be found, then the 
[clientside]
command can be used to change the request as needed...

when RULE_INIT {
    set static::new_app_pool "/Common/YOUR_NEW_APP_POOL" 
}
when HTTP_REQUEST_SEND {
    if { [members -list $static::new_app_pool] contains "[LB::server addr] [LB::server port]" } then {
        log -noname local0.debug "Match! [members -list $static::new_app_pool] contains [LB::server addr] [LB::server port]"
        clientside {
             Rewrite the request as needed...
        }
    } else {
        log -noname local0.debug "Don't match! [members -list $static::new_app_pool] contains [LB::server addr] [LB::server port]"
    }
}

Note: The pool YOUR_NEW_APP_POOL is just used to identify the new application servers. Its not used for LB or forwarding the traffic.

Cheers, Kai