tcl fbsd jail generation

 # Private Adapter
        $prv_adapter_id   = "10";
        $prv_adapter_name = "prv_netbox";
        $prv_adapter_desc = "prv_net:${name}";
        $prv_adapter_network  = "10.0.10.8/24";
        $prv_adapter_network_addr  = "10.0.10.8";
        $prv_adapter_network_route = "10.0.10.3";
 # Private Bridge
        $prv_bridge_network  = "10.0.10.7/24";
        $prv_bridge_name  = "private";
 # Private Interfaces
        $prv_epair = "epair${prv_adapter_id}";
        $prv_epaira = "epair${prv_adapter_id}a";
        $prv_epairb = "epair${prv_adapter_id}b";
        vnet.interface += "${prv_epairb}";
 ##########
 ## Private Networking Plumbing
 # Networking on parent (host)
  exec.prestart += "ifconfig ${prv_epair} create up"                     ;# Create the epair adapter
  exec.prestart += "ifconfig ${prv_epaira} up descr ${prv_adapter_desc}" ;# Add description to adapter
  exec.prestart += "ifconfig ${prv_epaira} name ${prv_adapter_name}"     ;# Rename adapter on parent
  exec.prestart += "ifconfig ${prv_bridge_name} addm ${prv_adapter_name}"   ;# Add the private adapter to the private bridge in child
        # Networking in child (jail)
         exec.start += "ifconfig ${prv_epairb} ${prv_adapter_network} up" ;# Add IP
         exec.start += "ifconfig ${prv_epairb} name ${prv_adapter_name}"  ;# Rename network adapter in child
         exec.start += "route add default ${prv_adapter_network_route}"   ;# Add defaulkt route
                # Bridge in child (jail)
                 exec.start += "ifconfig bridge create name ${prv_bridge_name}"         ;# Set the name of the private bridge
                 exec.start += "ifconfig ${prv_bridge_name} inet ${prv_bridge_network}" ;# Apply IP to bridge
                 exec.start += "ifconfig ${prv_bridge_name} addm ${prv_adapter_name}"   ;# Add the private adapter to the private bridge in child
 # Tidy-up networking
  exec.poststop  += "ifconfig ${prv_adapter_name} destroy" ;# Remove our adapter from the parent
  exec.poststop  += "arp -d ${prv_adapter_arp}"            ;# Remove our adapter from the arp table