Help deleting header name that contains curly braces

Amazing thing in iRules, you can submit to the original factory that this is a bug to be optimized or that iRules has a strange bug with "{"  or  "}" in the HTTP header

It may also be a disadvantage of the TCL language. Lists can be represented by "" or {}, which can sometimes be ambiguous, unlike Python lists, which can only be represented by []

Some manufacturers' load balancing scripts use lua language instead of tcl

I found that as long as the name field in the HTTP header contains {  or  }, HTTP:: header remove will report an error，

It seems that HTTP:: header remove name, name value refers to the value in HTTP:: header names storage format, rather than the value of variable string that we usually understand

log local0. "names is: [HTTP::header names]"          the log result is:

names is: Host User-Agent Accept {{esbsoapheader}userName} Connection {{esbsoapheader}userName}

HTTP header name {esbsoapheader}userName the storage format in [HTTP::header names] is {{esbsoapheader}userName}

so, we need to use this format HTTP::header remove {{{esbsoapheader}userName}}     or     

HTTP::header remove "{{esbsoapheader}userName}"

use HTTP::header remove {{esbsoapheader}userName} will raise error!

if we HTTP::header insert "\{esbsoapheaderuserName" "f5-gtm" 

the [HTTP::header names] running result is:

names is: Host User-Agent Accept \{esbsoapheaderuserName Connection

we need to this format to remove:

HTTP::header remove {\{esbsoapheaderuserName}

It seems that in the list of tcl, the element storage that contains {  or  } needs to carry {}

(bin) 49 % set a {Host User-Agent Accept {esbsoapheader}userName Connection}
Host User-Agent Accept {esbsoapheader}userName Connection
(bin) 50 % lindex $a 3
list element in braces followed by "userName" instead of space
(bin) 51 % string length $a
57

(bin) 53 % set a "Host User-Agent Accept {esbsoapheader}userName Connection"
Host User-Agent Accept {esbsoapheader}userName Connection

(bin) 55 % lindex $a 1
list element in braces followed by "userName" instead of space
(bin) 56 %

(bin) 57 % set a {Host User-Agent Accept {{esbsoapheader}userName} Connection}
Host User-Agent Accept {{esbsoapheader}userName} Connection

(bin) 62 % lindex $a 3
{esbsoapheader}userName

(bin) 63 % set qq "Host User-Agent Accept {{esbsoapheader}userName} Connection"
Host User-Agent Accept {{esbsoapheader}userName} Connection
(bin) 64 % lindex $qq 3
{esbsoapheader}userName
(bin) 65 %

(bin) 95 % set names_list {Host User-Agent Accept \{esbsoapheader\}userName Connection}
Host User-Agent Accept \{esbsoapheader\}userName Connection
(bin) 97 % lindex $names_list 3
{esbsoapheader}userName
(bin) 98 %

(bin) 70 % set names "Host User-Agent Accept \\{esbsoapheader\\}userName Connection"
Host User-Agent Accept \{esbsoapheader\}userName Connection
(bin) 71 % lindex $names 3
{esbsoapheader}userName

when HTTP_REQUEST {
    if { [HTTP::uri] eq "/demo2" } {
        HTTP::header insert "\{esbsoapheaderuserName" "spencer"
        HTTP::header insert Connection close
        HTTP::header insert "{esbsoapheader}userName" "f5-bigip"
        foreach aHeader [HTTP::header names] {
            log local0. "HTTP Request Headers: $aHeader: [HTTP::header value $aHeader]"
        }
        log local0. "exists header: [HTTP::header exists "{esbsoapheader}userName"]; value is [HTTP::header "{esbsoapheader}userName"]"
        log local0. "names is: [HTTP::header names]"
        log local0. "***************REMOVING BAD HEADER************"
        
        # set a "{esbsoapheader}userName"
        # HTTP::header remove [list $a]
        
        # HTTP::header remove "{{esbsoapheader}userName}"  it also works correct
        HTTP::header remove {{{esbsoapheader}userName}}
        HTTP::header remove {\{esbsoapheaderuserName}
        foreach aHeader [HTTP::header names] {
            log local0. "HTTP Request Headers: $aHeader: [HTTP::header value $aHeader]"
        }
    }
}

Hi Spencer_Aranda , 
Could you please specify if this header added at request or response time , also can you give a simulated sample to this header.
I will follow up your request. 
Regards 

Spencer_Aranda ,

when HTTP_REQUEST { 
     HTTP::header remove "{esbsoapheader}userName"
   }

it worked with me in my lab without errors , could you please share your irule script exactly. 

Regards

Hi Mohamed,

Thanks for your reply.  Here is the example.  I'm using this to test.  In the real scenario, the header name "{esbsoaheader}userName" was already found in the HTTP headers, but in this test scenario and I'm adding it and then trying to remove it.  I'm not sure how it worked for you.

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]"
}
}

}

LOGS

TCL error: /Common/ilxpi_demo/ilxir_demo <HTTP_REQUEST> - list element in braces followed by "userName" instead of space while executing "HTTP::header remove "{esbsoapheader}userName""

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     
  }
}