server.js

const express = require("express");
const mongoose = require("mongoose");
const bodyParser = require('body-parser');
const passport = require('passport');
const path = require('path');

const users = require('./routes/api/users');
const profile = require('./routes/api/profile');
const posts = require('./routes/api/posts');

const app = express();

//Body parser middleware
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json());

//DB Config
const db = require("./config/keys").mongoURI;

//Connect to MongoDB
mongoose
  .connect(db, { useNewUrlParser: true, useFindAndModify: false })
  .then(() => console.log("MongoDB Connected"))
  .catch(err => console.log(err));

// Passport middleware
app.use(passport.initialize());

// Passport Config
require('./config/passport.js')(passport);

//Use routes
app.use('/api/users', users);
app.use('/api/profile', profile);
app.use('/api/posts', posts);

// Serve static assets if in production
if (process.env.NODE_ENV === 'production') {
  // Set static folder
  app.use(express.static('client/build'));
  app.get('*', (req, res) => {
    res.sendFile(path.resolve(__dirname, 'client', 'build', 'index.html'));
  });
}

const port = process.env.PORT || 5000;

app.listen(port, () => console.log(`Server running on port ${port}`));