api.js

#!/usr/bin/env node
var rest = require('restify');
var ip = require('./ip');

function respond(req, res) {
  res.send(ip);
}

var server = rest.createServer();
server.get('/', respond);
server.head('/', respond);

server.listen(8080, function() {
  console.log('%s listening at %s', server.name, server.url);
});