add HTTP Header

I assume you have a scenario like this:

GET / HTTP/1.1

Host: somehost.example.com

ABC: abcs_value

And you want to check if there is an ABC header and if so insert a new header named EFG like this:

GET / HTTP/1.1

Host: somehost.example.com

EFG: efg_value

ABC: abc_value

If so, this should work:

 
 when HTTP_REQUEST { 
  
     Check if ABC header exists 
    if {[HTTP::header exists "ABC"]}{ 
  
        Save the value of ABC 
       set abc_value [HTTP::header value "ABC"] 
  
        Remove the ABC header 
       HTTP::header remove "ABC" 
  
        Insert the EFG header 
       HTTP::header insert "EFG" value "efg_value" 
  
        Insert the ABC header again so it's after the EFG header 
       HTTP::header insert "ABC" value $abc_value 
    } 
 } 
 

Note that I haven't tested it, but it looks about right. If you run into any issues, try adding some logging to the iRule.

Thanks,

Aaron