title: Node backpack exclude file from bundling
body: <p>I have the simplest backpack config like this:</p>
  
  <pre><code>module.exports = {
      webpack: (config, options, webpack) =&gt; {
        config.entry.main = [
          './app.js'
        ]
        return config;
      }
  }
  </code></pre>
  
  <p>But inside my app I have</p>
  
  <pre><code>const myConfig = require('./config/someConfiguration.json');
  </code></pre>
  
  <p>This file <code>./config/someConfiguration.json</code> should not be bundled so that it can be modified/configured. 
  I tried to do it like that:</p>
  
  <pre><code>module.exports = {
      webpack: (config, options, webpack) =&gt; {
        config.entry.main = [
          './app.js'
        ];
        config.externals = [
          './config/someConfiguration.json'
        ];
        return config;
      }
  }
  </code></pre>
  
  <p>But then I had 2 issues. One small one was that now I have to include the file like that <code>'../config/someConfiguration.json'</code> since it is required from the <code>./build/main.js</code> bundled script. The other issue was that MySQL module started to throw exception out of nowhere:</p>
  
  <pre><code>    this.handshake = Packets.Handshake.fromPacket(helloPacket);
                                         ^
  TypeError: Cannot read property 'fromPacket' of undefined...
  </code></pre>
  
  <p>Which I think means that I am not excluding the file from bundling as it should be. What's the proper way to solve this problem?</p>