FQDN Node with Route Domains

adding v2 as we had some issues with persistence so we needed to add source pool member persistent to make it work 

when RULE_INIT {
    # Debug level (set to 1 for logging, or 0 to disable logging)
    set static::sftpdebug_pool 1
    # Pool name
    set static::sftpfqdn_pool sftp_snf_uat_22_pool
}

when CLIENT_ACCEPTED {
    # Reject the traffic if the ROUTE::domain is not 1549
    if { [ROUTE::domain] != 1549 } {
        reject
        return
    }

    # Only apply this logic to TCP port 22 (SFTP)
    if { [TCP::local_port] == 22 } {
        # Check if the client IP address is in the Data Group (sftp_snf_parallel_dg)
        if { [class match [IP::client_addr] equals sftp_snf_parallel_dg] } {
            # Check if a node is already assigned for this source IP
            set nodemember [table lookup -subtable sftpsource:[IP::client_addr] "" ]

            if { $static::sftpdebug_pool > 0 } {
                log local0. "Selected previous member for [IP::client_addr]: $nodemember"
            }

            if { $nodemember == "" } {
                # Get the list of active pool members
                set members [active_members -list $static::sftpfqdn_pool]
                set member_count [llength $members]

                if { $member_count > 0 } {
                    # Implement round-robin selection based on a dynamic index
                    if {[info exists static::poolndx]} {
                        # Increment index and loop back if necessary
                        set static::poolndx [expr {($static::poolndx + 1) % $member_count}]
                    } else {
                        # Initialize the pool index on first use
                        set static::poolndx 0
                    }

                    # Select a member based on the index
                    set membaddr [lindex [lindex $members $static::poolndx] 0]

                    # Log selected member (for debugging)
                    if { $static::sftpdebug_pool > 0 } {
                        log local0. "Selected pool member: $membaddr%1549 port 22 (round-robin)"
                    }

                    # Store the selected node in the session table
                    set nodemember "$membaddr%1549:22"
                    table set -subtable sftpsource:[IP::client_addr] $nodemember "" 180

                    # Send traffic to the selected node
                    node $nodemember
                } else {
                    # No active members in the pool
                    log local0. "No active members in pool $static::sftpfqdn_pool"
                    reject
                    return
                }
            }

            # If a previous assignment exists, route traffic to the assigned node
            if { $static::sftpdebug_pool > 0 } {
                log local0. "Routing to previously assigned pool member: $nodemember"
            }
            node $nodemember
        } else {
            # Fallback to the default pool
            if { $static::sftpdebug_pool > 1 } {
                log local0. "Client IP [IP::client_addr] not in data group. Using fallback pool."
            }
            pool sftp.f5.com_22_pool
        }
    }
}