var network = require('network-config');

network.interfaces(function(err, interfaces){
  /* interfaces should be something like:

  [{
    name: 'eth0',
    ip: '1.1.1.77',
    netmask: '1.1.1.0',
    mac: 'aa:aa:aa:aa:aa:aa',
    gateway: '10.10.10.1'
   },
   { ... }, { ... }]
  */
 
});

network.configure('eth0', {
    dhcp: true,
    restart: false // don't restart networking service
}, function(err){
});