Server-side rendering (SSR) offers numerous benefits such as improved performance and better SEO. Webpack 5 introduces a powerful feature called Module Federation, which allows you to share JavaScript modules across multiple applications. In this blog post, we will explore how to integrate Module Federation with server-side rendered applications in Webpack 5.

What is JavaScript Module Federation?

JavaScript Module Federation is a feature in Webpack 5 that enables you to dynamically share JavaScript modules across multiple projects at runtime. It allows you to build microfrontends, where each application can be developed and deployed independently.

Integrating Module Federation with SSR

To integrate Module Federation with server-side rendered applications, you need to follow these steps:

1. Set up a server-side rendered application using a framework like React, Next.js, or Express.

2. Create a separate Webpack configuration for your server bundle.

   const path = require('path');
   
   module.exports = {
     mode: 'production',
     entry: './src/server.js',
     output: {
       filename: 'server.bundle.js',
       path: path.resolve(__dirname, 'dist'),
     },
     target: 'node',
     // Add necessary loaders and plugins for SSR
     module: {
       rules: [
         // ... server-side rendering loaders
       ],
     },
     // Add necessary plugins for SSR
     plugins: [
       // ... server-side rendering plugins
     ],
   };
   

3. Create a separate Webpack configuration for your client bundle.

   const path = require('path');
   
   module.exports = {
     mode: 'production',
     entry: './src/client.js',
     output: {
       filename: 'client.bundle.js',
       path: path.resolve(__dirname, 'dist'),
     },
     // Add necessary loaders and plugins for client-side rendering
     module: {
       rules: [
         // ... client-side rendering loaders
       ],
     },
     // Add necessary plugins for client-side rendering
     plugins: [
       // ... client-side rendering plugins
     ],
   };
   

4. Configure Module Federation in your client bundle Webpack configuration.

   const { ModuleFederationPlugin } = require('webpack').container;
   
   module.exports = {
     // ...
     plugins: [
       // ...
       new ModuleFederationPlugin({
         name: 'client',
         filename: 'remoteEntry.js',
         exposes: {
           './Button': './src/components/Button',
         },
       }),
     ],
   };
   

5. In your server bundle, import the remote module using the Module Federation remote loader.

   const React = require('react');
   const { renderToString } = require('react-dom/server');
   const { default: Button } = require('client/Button');
   
   const App = () => (
     <div>
       <Button />
     </div>
   );
   
   const markup = renderToString(<App />);
   

6. Build both the server and client bundles.

   webpack --config server.config.js
   webpack --config client.config.js
   

7. Start your server.

   node dist/server.bundle.js
   

With these steps, you have successfully integrated JavaScript Module Federation with your server-side rendered application.

Conclusion

JavaScript Module Federation in Webpack 5 provides a powerful way to share JavaScript modules across multiple applications. By integrating Module Federation with server-side rendered applications, you can build scalable and modular microfrontends. Follow the steps outlined in this blog post to seamlessly integrate Module Federation with your SSR application in Webpack 5.

#techblog #modfederation