Update from the maintainer: Unless you have a good reason to use Webpack with AWS lambda, you should use the default CDK construct (https://docs.aws.amazon.com/cdk/api/latest/docs/aws-lambda-nodejs-readme.html). It works really well and is even faster than this Webpack based project, thanks to esbuild. I initially wrote this Webpack based construct because, at the time, the official Node.js construct was very slow. Since September 2021 I now use the default Node.js construct.

Consider this package deprecated as I won't be maintaining it, but it works.

CDK Construct to build Node.js AWS lambdas using webpack

Table of contents:

• Usage example
• Features
• Why?
• Roadmap
• How to make changes and test locally
• WTF happened to the rollup version?
• Thanks

yarn add aws-lambda-nodejs-webpack

// infra/super-app-stack.js
const sns = require("@aws-cdk/aws-sns");
const subscriptions = require("@aws-cdk/aws-sns-subscriptions");
const core = require("@aws-cdk/core");
const { NodejsFunction } = require("aws-lambda-nodejs-webpack");

module.exports = class SuperAppProductionStack extends core.Stack {
  constructor(scope, id, props) {
    super(scope, id, props);

    const slackNotificationsLambda = new NodejsFunction(
      this,
      "slack-notifications-lambda",
      {
        entry: "events/slack-notifications.js", // required
      },
    );
  }
};

// events/slack-notifications.js
import { WebClient as SlackWebClient } from "@slack/web-api";

export function handler(event) {
  const message = event.Records[0].Sns.Message;
  // do something with message
}

• webpack 5
• compiles and deploys to Node.js 14.x by default
• fast, no-docker CDK construct
• lambda output only contains the necessary files, no README, tests, ...
• bundling happens in temporary directories, it never writes in your project directory
• source map support
• TypeScript support
• Babel support (preset-env)
• babel & webpack caching
• node_modules are split into a single vendor.js file. Allowing you to debug your own code in AWS console most of the time

There's already a dedicated aws-lambda-nodejs module for CDK but I had two major issues with it:

1. CDK uses docker for anything lambda build related. This means it mounts your whole Node.js project (not just the lambda code) inside Docker before running a bundler like Parcel. This is perfectly fine and performant on Linux and Windows, but this is extremely slow on macOS: a single cdk synth would take 2 minutes for a 3 lines lambda. Since it might take a very long time for Docker on macOS to get as fast as on Linux. Even their latest update (mutagen), while significantly faster, still takes 20s just to mount a Node.js project.
2. aws-lambda-nodejs generates a single file bundle with every local and external module inlined. Which makes it very hard to debug and read on the AWS console. I wanted a lambda output that mimicks my project file organization.

I want to be clear: I respect a LOT the work of the CDK team, and especially @jogold, author of aws-lambda-nodejs) that helped me a lot into debugging performance issues and explaining to me how everything works.

⚠️ the only configuration file from your project that we will read is tsconfig.json (not including compilerOptions, which are overwritten using https://www.npmjs.com/package/@tsconfig/node12).

Other files won't be used (example: .babelrc). If you need to reuse part of your babel configuration, please open an issue with details on your usecase so we can build the best API for how to do this.

// fork and clone
cd aws-lambda-nodejs-webpack
yarn
yarn link
yarn start

# in another terminal and project where you want to test changes
yarn link aws-lambda-nodejs-webpack
# cdk commands will now use your local aws-lambda-nodejs-webpack

• the CDK team for this awesome project
• @jogold for his time while helping me debugging performance issues on Docker