web.js

const http = require('http')
const util = require('util')
const querystring = require('querystring')
const client = require('mongodb').MongoClient

const uri = process.env.MONGOLAB_URI || 'mongodb://@127.0.0.1:27017/messages'
//MONGOLAB_URI=mongodb://user:pass@server.mongohq.com:port/db_name

client.connect(uri, function(error, db) {
  if (error) return console.error(error)
  const collection = db.collection('messages')
  const app = http.createServer(function (request, response) {
    const origin = (request.headers.origin || '*')
    if (request.method == 'OPTIONS') {
      response.writeHead('204', 'No Content', {
        'Access-Control-Allow-Origin': origin,
        'Access-Control-Allow-Methods':
          'GET, POST, PUT, DELETE, OPTIONS',
        'Access-Control-Allow-Headers': 'content-type, accept',
        'Access-Control-Max-Age': 10, // In seconds
        'Content-Length': 0
      })
      response.end()
    } else if (request.method === 'GET' && request.url === '/messages.json') {
      collection.find().toArray(function(error,results) {
        if (error) return console.error(error)
        const body = JSON.stringify(results)
        response.writeHead(200,{
          'Access-Control-Allow-Origin': origin,
          'Content-Type':'text/plain',
          'Content-Length':body.length
        })
        console.log('LIST OF OBJECTS: ')
        console.dir(results)
        response.end(body)
      })
    } else if (request.method === 'POST' && request.url === '/messages.json') {
      request.on('data', function(data) {
        console.log('RECEIVED DATA:')
        console.log(data.toString('utf-8'))
        collection.insert(JSON.parse(data.toString('utf-8')),
        {safe:true}, function(error, obj) {
          if (error) return console.error(error)
          console.log('OBJECT IS SAVED: ')
          console.log(JSON.stringify(obj))
          const body = JSON.stringify(obj)
          response.writeHead(200,{
            'Access-Control-Allow-Origin': origin,
            'Content-Type':'text/plain',
            'Content-Length':body.length
          })
          response.end(body)
        })
      })
    } else {
    	response.end('Supported endpoints: \n/messages.json\n/messages.json')
    }
  })
  const port = process.env.PORT || 1337
  app.listen(port)
})