https rewrite

Hmm, I am a little baffled why it’s not working. I wonder if it’s because you are not setting up your request to HTTP/1.1. Try modifying the rule this way …

when HTTP_REQUEST {
   HTTP::version 1.0
 }
 when HTTP_RESPONSE {
   HTTP::collect 4294967295
 }
 when HTTP_RESPONSE_DATA {
        set find " Welcome" 
        set replace "===============Test Rewrite==============="
        set offset 0
        set diff [expr [string length $replace] - [string length $find]]
         Get indices of all instances of find string in the payload
        set indices [regexp -all -inline -indices $find [HTTP::payload]]
        puts "Got Payload \n[HTTP::payload]"
        if { $indices ne "" } {
                puts "iRule: wsu - Search Found $indices"
        } else {
                puts "iRule: wsu - Search Not Found"
        }
        foreach idx $indices {
                set start [expr [lindex $idx 0] + $offset]
                set end [expr [lindex $idx 1] + $offset]
                set len [expr {$end - $start + 1}]
                 replace the instance of find with the contents of replace
                HTTP::payload replace $start $len $replace
                puts "\nNew Payload \n[HTTP::payload]"
                 modify offset if the replace string is larger or smaller
                 than find.
                incr offset $diff
        }
 }

Alternatively, this shorter version of the rule might also do the trick for you.

when HTTP_REQUEST {
   HTTP::version 1.0
 }
 when HTTP_RESPONSE {
   HTTP::collect 4294967295
 }
 when HTTP_RESPONSE_DATA {
        set find " Welcome" 
        set replace "===============Test Rewrite==============="
        set payload [HTTP::payload]
        if {[regsub -all $find $payload $replace new_response] > 0} {
           HTTP::payload replace 0 [HTTP::payload len] $new_response
        }
}