const getData = res => httpntlm.get(
  {
    url,
    username: 'my_user',
    password: 'my_pass'
  },
  (err, resp) => {
    if (err) return err;
    res.send(JSON.parse(resp.body));
  }
);

router.get('/', function(req, res, next) {
  getData(res);
});