bootstrap-vz/common/tasks/network-configuration.json

// This is a mapping of Debian release codenames to NIC configurations
// Every item in an array is a line
{
"squeeze": ["auto lo",
            "iface lo inet loopback",
            "auto eth0",
            "iface eth0 inet dhcp"],
"wheezy": ["auto eth0",
           "iface eth0 inet dhcp"],
"jessie": ["auto eth0",
           "iface eth0 inet dhcp"]
}