config-wrapper.js

//------------------------------------------------------------------------------
// Copyright IBM Corp. 2015, 2016
//
// 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.
//------------------------------------------------------------------------------

var mqtt = require('mqtt');
var properties = require('properties');
var mqttHost = "test.mosquitto.org";
var mqttPort = 1883;
var deviceId;
var subscriptionnamePrefix = "hackathon2-ecxio/car/";

function start(carid, startlane, callback) {
  var mqttClient = mqtt.connect("mqtt://" + mqttHost + ":" + mqttPort, {
      "keepalive" : 30
  });

  mqttClient.on('connect', function() {
    mqttClient.subscribe(subscriptionnamePrefix + deviceId + '/#', {qos : 0}, function(err, granted) {
      if (err) {
        mqttClient = null;
      } 
      else {
        console.log('MQTT client connected to ' + mqttHost);
      }
    });
    callback(carid, startlane, mqttClient, deviceId);
  });
}

module.exports = function() {
  return {
    "read" : function(propertiesFileName, callback) {
      if (!propertiesFileName) {
        propertiesFileName = 'config-gs.properties';
        console.error('Default configuration file config-gs.properties is used');
      }
      properties.parse('./' + propertiesFileName, {path: true}, function(err, cfg) {
        if (err) {
          console.error('Error parsing the configuration file - see config-sample.properties for an example');
          process.exit(0);
		    }
        if (!cfg.carid) {
          console.error('Error parsing the configuration file - see config-sample.properties for an example');
          process.exit(0);
        }
        deviceId = cfg.deviceid;
        start(cfg.carid, cfg.startlane, callback);
      });	
	  }
  };
};