Running a node express server using webpack-dev-server

Question

I'm using webpack to run my react frontend successfully using the following config:

{
    name: 'client',
    entry: './scripts/main.js',
    output: {
        path: __dirname,
        filename: 'bundle.js'  
    },
    module: {
        loaders: [
            {
                test: /.jsx?$/,
                loader: 'babel-loader',
                exclude: /node_modules/,
                query:{
                    presets: ['es2015', 'react', 'stage-2']
                }
            }
        ]
    }
}

I'm trying to put up a node.js express backend as well, and would like to run that through webpack as well, so that I have a single server running both the backend and frontend, and because I want to use babel to transpile my javascript.

I made a quick testserver looking like this:

var express = require('express');
console.log('test');

var app = express();

app.get('/', function(req, res){
    res.send("Hello world from Express!!");
});

app.listen(3000, function(){
    console.log('Example app listening on port 3000');
});

If I run this with node index.js and open my browser on localhost:3000 it prints "Hello world from Express!!". So far so good. Then I tried creating a web-pack config for it:

var fs = require('fs');
var nodeModules = {};
fs.readdirSync('node_modules')
    .filter(function(x) {
        return ['.bin'].indexOf(x) === -1;
    })
    .forEach(function(mod) {
        nodeModules[mod] = 'commonjs ' + mod;    
});

module.exports = [
{
    name: 'server',
    target: 'node',
    entry: './index.js',
    output: {
        path: __dirname,
        filename: 'bundle.js'
    },
    externals: nodeModules,
    module: {
        loaders: [
            { 
                test: /\.js$/,
                loaders: [
                    'babel-loader'
                ]
            },
            {
                test:  /\.json$/, 
                loader: 'json-loader'
            }
        ]
    }
}   

When I run the command webpack-dev-server it starts up successfully (it seems). However, if I go to my browser on localhost:3000 now, it just says that the webpage is not available, just as when the server is not running at all.

I'm very new to both node and webpack, so either I have made a small mistake somewhere, or I'm way off ;)

Answer 1

Webpack-dev-server is great for client side development but it will not deploy Express api's or middleware. So in development I recommend running two separate servers: One for the client and one for your server side api's.

Nodemon npm install --save-dev nodemon is a good backend development server that will give you hot-redeploy of your api's, or you can just use express and restart when you make changes. In production the client and api will still be served by the same express server.

Set a lifecycle event for both nodemon and webpack-dev-server in your package.json to make starting them easy (example: npm run dev-server).

"scripts": {
   "start": "webpack --progress --colors",
   "dev-server": "nodemon ./server.js localhost 8080",
   "dev-client": "webpack-dev-server --port 3000",
}

Or, to run express directly from node:

"scripts": {
   "start": "webpack --progress --colors",
   "dev-server": "node dev-server.js",
   "dev-client": "webpack-dev-server --port 3000",
}

// dev-server.js
const express = require('express');
const app = express();
// Import routes
require('./_routes')(app);   // <-- or whatever you do to include your API endpoints and middleware
app.set('port', 8080);
app.listen(app.get('port'), function() {
    console.log('Node App Started');
});

Note: The api server must use a different port than webpack-dev-server.

And finally in your webpack-dev-config you need to use a proxy to redirect calls to your api to the new port:

devServer: {
  historyApiFallback: true,
  hot: true,
  inline: true,

  host: 'localhost', // Defaults to `localhost`
  port: 3000, // Defaults to 8080
  proxy: {
    '^/api/*': {
      target: 'http://localhost:8080/api/',
      secure: false
    }
  }
},
// and separately, in your plugins section
plugins: [
  new webpack.HotModuleReplacementPlugin({
    multiStep: true
  })
]

**Bonus points for having a single script to start and kill both