Forum Discussion

Brandon's avatar
Brandon
Icon for Cirrostratus rankCirrostratus
Feb 03, 2021

irule to look to see if the value is in the Body

I was trying to figure out how to write an iRule to look for a parameter in the Body. I thought the token would be in the header. However the developer put it in the body. How do I look in the body o...
application delivery
BIG-IP
iRules
Amine_Kadimi's avatar
Amine_Kadimi
Icon for MVP rankMVP
when HTTP_REQUEST {
  if {[HTTP::method] eq "POST"}{
    if {[HTTP::header "Content-Length"] ne "" && [HTTP::header "Content-Length"] <= 1048576}{
      set content_length [HTTP::header "Content-Length"]
    } else {
        set content_length 1048576
    }
    if { $content_length > 0} {
      HTTP::collect $content_length
    }
  }
}
when HTTP_REQUEST_DATA {
  log local0. "Token = [findstr [HTTP::payload] "token=" 6 &]"
}

source: https://support.f5.com/csp/article/K07535385

Daniel_Wolf's avatar
Daniel_Wolf
Icon for MVP rankMVP
Feb 04, 2021

This is the way, however I would be careful to implement it. I'd recommend to do performance testing before deploying it in a production environment.

Just recently I had a similar requirement and it works good with small requests. However the customer had POST requests up to 400kb. Then this suddenly becomes heavy on the CPU.