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KimiLi_147173's avatar
KimiLi_147173
Icon for Nimbostratus rankNimbostratus
Nov 27, 2017
Solved

Want to rewrite part of host

Hi guys, I'm still new to iRules, I wonder that if it is possible that an iRule can rewrite part of the host instead of all of it.   I mean like, if a client request a host like "123.aaa.com/888/"...
application delivery
LTM
  • Samir_Jha_52506's avatar
    Samir_Jha_52506
    Nov 28, 2017

    If string position is known then you can use 

    getfield
    function to grep value like below. 

    set hostname [getfield [HTTP::host] "." 1]   If the URL is xxx.aaa.bbb.com, then getfield command will grep value of 1st position xxx
set hostname1 [getfield [HTTP::host] "." 2]   If the URL is xxx.aaa.bbb.com, then getfield command will grep value of 2nd position aaa

    Refer below link. Hope it will be helpful.

Samir_Jha_52506's avatar
Samir_Jha_52506
Icon for Noctilucent rankNoctilucent
Nov 28, 2017

If string position is known then you can use 

getfield
function to grep value like below. 

set hostname [getfield [HTTP::host] "." 1]   If the URL is xxx.aaa.bbb.com, then getfield command will grep value of 1st position xxx
set hostname1 [getfield [HTTP::host] "." 2]   If the URL is xxx.aaa.bbb.com, then getfield command will grep value of 2nd position aaa

Refer below link. Hope it will be helpful.

KimiLi_147173's avatar
KimiLi_147173
Icon for Nimbostratus rankNimbostratus
Nov 28, 2017

Hi f5_rock,

YOU'RE THE MAN!

I believe this is what I want, according to your suggestion I've got an irule like this:

when HTTP_REQUEST {
 Check if host contains "aaa.com"
if {[HTTP::host] contains "aaa.com"}{
     Get the xxx from host xxx.aaa.com
    HTTP::redirect "https://[getfield [HTTP::host] "." 1].bbb.com[HTTP::uri]"
   }
}

And it works! I'll keep on doing further tests to figure out if there's still room to make it better.

Thanks again!