Forum Discussion

Altocumulus

Nov 18, 2022

Help deleting header name that contains curly braces

Hi Just a quick question. I was asked to use the F5 to remove a header name as follows {esbsoapheader}userName The header value was just fine. But I was asked to remove {esbsoapheader} from heade...

application delivery

Spencer_Aranda

Nov 18, 2022

I think I just figured it out guys Mohamed_Ahmed_Kansoh CA_Valli

Paste this and run it. It worked out for me. Now any of you can explain why this works?? Is this a bug with F5? At least it seems to me. If it is, how can I let them know so they can fix it.

when HTTP_REQUEST {
  if { [HTTP::uri] eq "/demo2" } {
    HTTP::header insert "{esbsoapheader}userName" "spencer"
    foreach aHeader [HTTP::header names] {
      log local0. "HTTP Request Headers: $aHeader: [HTTP::header value $aHeader]"
    }
    log local0. "***************REMOVING BAD HEADER************"
    HTTP::header remove "\\{esbsoapheader\\}userName"
    foreach aHeader [HTTP::header names] {
      log local0. "HTTP Request Headers: $aHeader: [HTTP::header value $aHeader]"
    }
  }
}

CA_Valli

MVP

Nov 18, 2022

Hello, I'd love to help you out but this is turning out to be tricky.

It's not possible to edit header name directly via iRule, so my code retrieves {esbsoapheader}userName value and inputs it into a new userName header. Then I'm attempting to delete {esbsoapheader}userName -- but this fails. I see iRule execution crashes and cllient connection is reset.

I've tried escaping curly braces with "\" as well, or passing it via a variable, but it doesn't seem to work.

Will it be enough to just insert userName? Is it a problem if {esbsoapheader}userName exists in request?

Sharing my progress so far.

when HTTP_REQUEST {
  if { [HTTP::header exists "{esbsoapheader}userName"] }{ 
       HTTP::header insert userName [HTTP::header "{esbsoapheader}userName"]
# non-working code
#       HTTP::header remove "{esbsoapheader}userName"
#       HTTP::header remove "\{esbsoapheader\}userName"
#       HTTP::header remove \{esbsoapheader\}userName
#       set hnme "{esbsoapheader}userName" ;  HTTP::header remove $hname     
  }
}

Spencer_Aranda
Altocumulus
Nov 18, 2022
Thank you for taking the time to look into this CA_Valli
What you just showed to me is the fix that I gave the people that first asked me to remove {esbsoapheader} from header name.
I ended up just inserting a new header name just with userName and did not remove the bad header name. However, this is not quite what they were looking for so that is why I came to the F5 forum to look for answers.
I'm extremely curious how it worked out for Mohamed_Ahmed_Kansoh ...
Spencer_Aranda
Altocumulus
Nov 18, 2022
CA_Valli Do you know why it is not possible to remove "{esbsoapheader}userName"? Is it because the header name is using characters that are not legal to use in a header name? If so, do you have some resource that I can read to confirm?
- Mohamed_Ahmed_Kansoh
  MVP
  Nov 18, 2022
  it does not work with me ,
  I meant the iRule script is correct and accepted , I thought you have a problem with that.
  No I have performed your script on my test lab and I saw the TCL error:
  Let me see how can I remove it , if I found a workaround , definitely I will share it with you
  
  Regards
  - Mohamed_Ahmed_Kansoh
    MVP
    Nov 18, 2022
    Spencer_Aranda ,
    you are right ,
    the issue exactly with remove and {} , I replaced {} with // and it works well.
    I think you must change the inserted header and not use {}.
    I tried to put this header in variale , and delete this variable but without Luck.
    what a strange thing !!
    why irule executed well without errors , and couldn’t perform the task of delete.