server.js

const express = require('express');
const router = express.Router();
const app = express();
const port = process.env.PORT || 3000;

//Allows use of enviroment variables
require('dotenv').config({ path: __dirname + '/.env' });

//API Routes
const users = require('./routes/users');
const customers = require('./routes/customers');


//Mongoose connection
const mongoose = require('mongoose');
//process.env.MLAB_URL comes from the .env file via dotenv
const mongoDB = process.env.MONGODB_URI || process.env.MLAB_URL;
mongoose.connect(mongoDB, {useNewUrlParser: true });
mongoose.Promise = global.Promise;
const db = mongoose.connection;
db.on('error', console.error.bind(console, 'MongoDB connection error:'));

app.use(express.urlencoded({ extended: true }));
app.use(express.json());

//Use API routes
//API routes
app.use('/users', users);
app.use('/customers', customers);

app.listen(port, (err) => {
    if (err)
        throw err;
    else
        console.info(`****** Node server is running on ${port} ******`);
});