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Stephane_87808's avatar
Stephane_87808
Icon for Nimbostratus rankNimbostratus
Nov 20, 2009

Assign a Pool AND rewrite an url

Hello

 

 

Is there a way :

 

- to assign a POOL of servers

 

and

 

- to rewrite the URL (adding a /xx.htm)

 

 

when a condition is matched in a irule ?

 

 

(of course, I will not declare any Default Pool of server for the corresponding VS)

 

 

 

As we need to start multiple webservers running on differents http ports (http://inter1.alk.com:8031/inter1, http://inter2.alk.com:8032/inter2, http://inter3.alk.com:8033/inter3, etc....), I would like to use only ONE VS and have the benefit from the irule capabilities to select the right pool of servers.

 

 

in addition, all the pools of servers we have defined can be the exact same servers, with the same ip addresses : the differents pools are only there to declare the differents ports we will use.

 

 

 

 

In the example below, the line "pool ..." only means what I would expect.

 

 

----------------------------------------

 

when HTTP_REQUEST {

 

if {[HTTP::host] equals "inter1.alk.com" and [HTTP::uri] equals "/" }

 

{

 

pool Pool_inter1

 

HTTP::redirect http://[getfield [HTTP::host] ":" 1]:8030/inter1

 

}

 

elseif {[HTTP::host] equals "inter2.alk.com" and [HTTP::uri] equals "/"}

 

{

 

pool Pool_inter1

 

HTTP::redirect http://[getfield [HTTP::host] ":" 1]:8031/inter2

 

}

 

}

 

----------------------------------------

 

 

 

Thanks for any help / advice

 

 

Stéphane

 

application delivery
dev
devops
iRules
v4
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Nov 20, 2009
    Hi Stéphane,

    HTTP::redirect will result in LTM sending the client a 302 redirect to the new location. It sounds like you want to rewrite the URI. You can do this using HTTP::uri: 

     
  
 when HTTP_REQUEST { 
  
    log local0. "[IP::client_addr]:[TCP::client_port]: New [HTTP::method request to [HTTP::host][HTTP::uri]" 
  
     Check if the URI is / 
    if {[HTTP::uri] eq "/"} { 
  
       log local0. "[IP::client_addr]:[TCP::client_port]: Matched URI check for /" 
  
        Check the requested host (set to lower case) 
       switch [string tolower [HTTP::host]] { 
  
          "inter1.alk.com" { 
     log local0. "[IP::client_addr]:[TCP::client_port]: Matched inter1." 
     pool Pool_inter1 
     HTTP::uri "/inter1" 
  } 
          "inter2.alk.com" { 
     log local0. "[IP::client_addr]:[TCP::client_port]: Matched inter2." 
     pool Pool_inter2 
     HTTP::uri "/inter2" 
  } 
          default { 
     log local0. "[IP::client_addr]:[TCP::client_port]: No match on Host header value" 
  } 
       } 
    } 
 }

    This example checks for a URI of /, then sets the Host header value to lower case and checks for inter1.alk.com or inter2.alk.com. The corresponding pool is then selected and the URI is rewritten to /inter where is 1 or 2.

    You may want to consider handling the default case where someone requests a different host header (or IP address) with a URI of /. That wouldn't be modified by this rule and would be sent to the default pool on the VIP if one is configured.

    You can check the /var/log/ltm output from the debug logging. Once done testing either comment out or remove the debug log statements.

    Aaron