code: function(hostname, callback) {
    get_nodes(function(err,nodes) {
      if (err) return callback(err);
  
      var n = nodes.filter(function(node) {
        return node.name === hostname;
      });
  
      callback(null,(n.length === 1) ? n[0].ip_address : null);
    });
  }
docs: Callsback an ip address or null if can't find the hostname