How to tell webpack to ignore node modules, both core and installed from npm?

Question

I need to pack a module I've written with webpack and transpile with babel. However I don't want to pack anothing from node_modules. Also, Node.js core modules shouldn't be packed.

I get these errors for core modules:

ERROR in ./node_modules/tunnel-agent/index.js
Module not found: Error: Can't resolve 'net' in '...project path...\node_modules\tunnel-agent'
 @ ./node_modules/tunnel-agent/index.js 3:10-24
 @ ./node_modules/request/lib/tunnel.js
 @ ./node_modules/request/request.js
 @ ./node_modules/request/index.js

So clearly, webpack is crawling node modules, that's something I don't want. It also clearly tries to load modules like net and fs.

How to stop this, and only pack and transpile my own code?

My config:

const path = require('path');
module.exports = {
    entry: './serverless_function.js',
    output: {
        path: path.resolve('dist'),
        filename: 'serverless_packed.js'
    },
    module: {
        loaders: [
            { test: /\.js$/, loader: 'babel-loader', exclude: /node_modules/ },
            { test: /\.jsx$/, loader: 'babel-loader', exclude: /node_modules/ }
        ]
    }
}

I need to pack my serverless function to be compatible with Node.js 6, which runs on Amazon AWS. It looks like this:

const Library = require("./MyLibrary");
const fs = require("fs");

async function serverlessFunction(event, context, callback) {
    const response = {
        statusCode: 200,
        headers: {

            "Content-Type": "image/png",
            "Content-Disposition": "inline; filename=\"something.png\""
        },
        body: await Library.createImage().asBase64String("param1", "param2"),
        isBase64Encoded: true
    };
    return callback(null, response);
}

module.exports = { serverlessFunction };

Answer 1

You can use the module webpack-node-externals to do exactly this:

const path = require('path');
const nodeExternals = require('webpack-node-externals');

module.exports = {
    entry: './serverless_function.js',
    output: {
        path: path.resolve('dist'),
        filename: 'serverless_packed.js'
    },

    // in order to ignore built-in modules like path, fs, 
    target: 'node',

    // in order to ignore all modules in node_modules folder 
    externals: [nodeExternals()],

    module: {
        loaders: [
            { test: /\.js$/, loader: 'babel-loader', exclude: /node_modules/ },
            { test: /\.jsx$/, loader: 'babel-loader', exclude: /node_modules/ }
        ]
    }
}