Passing a header value to lb to pool

Sorry, forgot to format the code section

Code
when RULE_INIT {
set newpool "";
}

when HTTP_RESPONSE {
  if { [HTTP::header exists "X-Load-Balancer-Pool"] }  { 
    set newpool [HTTP::header value "X-Load-Balancer-Pool" ]
    log local0. "Header found to be $newpool"
    HTTP::cookie insert name "Load-Balancer-Pool-cookie" value "$newpool"
  } else {
    log local0. "Header not found $newpool" 
    return 
  }
}

when HTTP_REQUEST {
  if { [HTTP::cookie exists "Load-Balancer-Pool-cookie"] }  { 
    set cookie_pool [HTTP::cookie value "Load-Balancer-Pool-cookie" ]
    log local0. "Header found to be $cookie_pool"
    pool $cookie_pool
  } else {
    log local0. "pool not found" 
    return 
  }
}

At first glance, you are only directing to a pool in the HTTP_Request section. You are not actually setting persistence or directing to a specific node. Take a peek at this example which demonstrates how to set the pool member. Also, what unique value will you look at in the cookie? I'd also recommend encrypting the cookie just to obscure any internal detail that does not need to be plain text!

https://devcentral.f5.com/wiki/irules.manual_cookie_persistence.ashx

A few questions:

1. Can you elaborate on why you're doing this?

    

2. Do you have a default pool assigned to the VIP? Without it the initial request, without the cookie, wouldn't know where to go.

    

3. What are the log messages you're getting, and where is it failing?

    

To decrypt/encrypt cookies... create values for your cookie name $ckname, and cookie password $ckpass in the client connected event.

when CLIENT_ACCEPTED {
      Name for the cookie to be inserted to maintain client session
     set ckname 
      Encryption password to be used for encrypting / decrypting the user session cookie
     set ckpass 
  }
when HTTP_REQUEST {
     if {[HTTP::cookie exists $ckname]} {
          Decrypt the cookie so we can use the values in it
          HTTP::cookie decrypt $ckname $ckpass 128
     }
}
when HTTP_RESPONSE {
        Set up your cookie details here
        Now to encrypt your cookie
 HTTP::cookie encrypt $ckname $ckpass 128 
}