modify original headers on HTTP:retry

when HTTP_REQUEST {

    log local0. "[IP::client_addr]:[TCP::client_port]: [HTTP::method] request to [IP::local_addr]:[TCP::local_port] \
        [HTTP::host][HTTP::uri], auth_cookie=[HTTP::cookie "userauth"]"

     Track whether to insert the auth pool's auth cookie in responses to the client
       Don't do this by default, unless we've received a successful auth response
    set insert_cookie 0

     Track whether to perform auth against the auth pool
       Do this by default, unless we've received a successful auth response
    set do_auth 1

     Check if auth was already successful
    if { [HTTP::cookie "userauth"] ne "" }
    {
         Request has a userauth cookie, so check it against the LTM session table
        log local0. "[IP::client_addr]:[TCP::client_port]: Auth cookie present: [HTTP::cookie "userauth"]"

if {[session lookup uie [HTTP::cookie "userauth"]] eq ""}
{
     Auth token doesn't exist in session table to send request to auth pool
            log local0. "[IP::client_addr]:[TCP::client_port]: Auth cookie not in LTM session table, reauthing."
        }
else {
     Auth was successful, so use the webserver pool
    log local0. "[IP::client_addr]:[TCP::client_port]: Auth cookie present, using webserver pool"
    set do_auth 0
        }
    }
     Check if auth was already successful and this is an HTTP::retry request
    elseif {[info exists auth_token] and $auth_token ne ""}{

        log local0. "[IP::client_addr]:[TCP::client_port]: userauth cookie not present, but auth was just successful"
set do_auth 0

         Insert the authcookie in the request
        HTTP::cookie insert name authcookie value $auth_token

 Track that we also need to insert the cookie in the response so the client will present it in 
   subsequent requests
set insert_cookie 1
    }
    if { $do_auth==1 }
    {
         Need to authenticate request, so use the auth pool
        log local0. "[IP::client_addr]:[TCP::client_port]: Performing auth using authserver pool"
        pool authserver

 Save original request headers to retry request against webserver pool if auth succeeds
        set orig_request_headers [HTTP::request]
    }
    else {
         Auth was successful, so use the webserver pool
        log local0. "[IP::client_addr]:[TCP::client_port]: Using webserver pool"
pool webserver
    }
}

when HTTP_RESPONSE {

    log local0. "[IP::client_addr]:[TCP::client_port]: pool: [LB::server], status: [HTTP::status]"

     Check if auth was successful
    if { $do_auth==1 and [HTTP::header exists "userauth"] and [HTTP::status] == 200}
    {
         Save the auth token value from the auth server
        set auth_token [HTTP::cookie "authcookie"]

 Add the auth cookie value to the LTM session table with any value using a timeout of 1800 seconds 
  so we can verify the client has a valid auth token on subsequent requests
        session add uie $auth_token 1 1800

         Retry the request so we can send it to the server pool
        HTTP::retry $orig_request_headers
    }
    else {
         Unset the auth_token variable to ensure a prior value isn't used for this connection
   Use catch to handle the case where auth_token hasn't been set
        catch {unset auth_token}

         Check if we need to insert the auth pool's auth cookie in responses to the client
        if { $insert_cookie==1 }{
            HTTP::cookie insert name authcookie value $auth_token path "/"
        }
    }
}