A small command-line Node module that allows Angular CLI's Webpack config file to be customized

npm install @angular/cli -g
npm install angular-cli-customizer -g

1. Define a webpack.config.js file at the root of your project containing the Webpack configuration settings you wish modify/add to the Angular CLI's build:

const path = require('path');

module.exports = {
    resolve: {
        alias: {

            // all upgraded AngularJS modules will now be forced to
            // use the same version of AngularJS, removing the
            // "Tried to load angular more than once." warning.
            angular: path.resolve(__dirname, 'node_modules/angular')
        }
    }
};

2. Use the command line interface exposed by this module - cng (think "customized" ng) - exactly as you would with the @angular/cli module (ng):

cng serve --open

The cng command is simply a wrapper for the ng command, so its API is identical to the standard ng command!

Angular's CLI is a fantastic tool for generating and developing Angular applications. Unfortunately, it has one major flaw - at the time of writing, there is no way to customize or extend the CLI's stock functionality. Even though the Angular CLI is built on top of the infinitely configurable Webpack, the CLI doesn't allow its internal Webpack configuration to be altered.

This module does some acrobatics (modifying the require function) to surgically replace the internal function (buildConfig()) that is responsible for generating the CLI's Webpack configuration object. The replacement function takes the result of the original buildConfig() call, merges in any changes defined in the custom webpack.config.js file, and returns the merged result.

Other than that, the cng command is simply a wrapper for the ng command.

If you run ng eject, the Angular CLI will create a webpack.config.js file at the root of your project's directory that contains the configuration it uses at runtime. You can use this file as a reference when designing your own webpack.config.js file that will augment this configuration.

Note that running ng eject prevents the usage of some CLI features; to "uneject", delete the generated webpack.config.js and flip the ejected property to false in your project's .angular.cli.json.

Yep. It depends on internal implementation details of the CLI, which could change during any update of the @angular/cli package. Hopefully a better customization solution will be eventually be built into the CLI.