Azure Websites node.js http requests failing

I'm experimenting with the free tier of Azure websites using node.js and git deployment. It's very slick, but I'm trying to make a web service call to Facebook in one of my handlers, and it fails with a 500 internal server error and the following stack trace:

Application has thrown an uncaught exception and is terminated:
Error: connect EADDRNOTAVAIL
at errnoException (net.js:670:11)
at connect (net.js:548:19)
at Socket.connect (net.js:613:5)
at Object.<anonymous> (net.js:77:12)
at new ClientRequest (http.js:1091:25)
at Object.request (http.js:1427:10)
at Object.get (http.js:1432:21)

The code works fine when run locally. Is this a limitation of Azure websites, or is there some other way to make this work? My code looks like this (I'm using express):

app.get('/login', function (req, res) {
  var tokenUrl = 'http://foo.com';
  var body = '';
  http.get(tokenUrl, function (tokenRes) {
    tokenRes.on('data', function (chunk) {
      body += chunk;
    }).on('end', function () {
      res.end(body);
    });
  }).on('error', function (err) {
    console.log('Error fetching site: ' + err.message);
  });
}