app.js

/**
 * Copyright 2015 IBM Corp. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

'use strict';

var express  = require('express'),
  app        = express(),
  request    = require('request'),
  bluemix    = require('./config/bluemix'),
  extend     = require('util')._extend;

// Bootstrap application settings
require('./config/express')(app);

// if bluemix credentials exists, then override local
var credentials =  extend({
  url: '<url>',
  username: '<username>',
  password: '<password>'
}, bluemix.getServiceCreds('watson_dialog_service')); // VCAP_SERVICES

if (credentials.url.indexOf('/api') > 0)
  credentials.url = credentials.url.substring(0, credentials.url.indexOf('/api'));

// HTTP proxy to the API
app.use('/proxy', function(req, res) {
  var newUrl = credentials.url + req.url;
  req.pipe(request({
    url: newUrl,
    auth: {
      user: credentials.username,
      pass: credentials.password,
      sendImmediately: true
    }
  }, function(error){
    if (error)
      res.status(500).json({code: 500, error: errorMessage});
  })).pipe(res);
});

// render index page
app.get('/', function(req, res) {
  res.render('index');
});

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.code = 404;
  err.message = 'Not Found';
  next(err);
});

// 500 error message
var errorMessage = 'There was a problem with the request, please try again';

// non 404 error handler
app.use(function(err, req, res, next) {
  var error = {
    code: err.code || 500,
    error: err.message || err.error || errorMessage
  };

  console.log('error:', error);
  res.status(error.code).json(error);
});

var port = process.env.VCAP_APP_PORT || 3000;
app.listen(port);
console.log('listening at:', port);