s6-envdir /etc/s6-linux-init/env-stage2
multisubstitute
{
  importas -i ETH0_IP4 ETH0_IP4
  importas DEFAULT_ROUTER_IP4 DEFAULT_ROUTER_IP4
}
if { ip addr add ${ETH0_IP4}/24 dev eth0 }
foreground { ip route del default }
route add default gw ${DEFAULT_ROUTER_IP4}