(aws-lambda-nodejs): export esbuild asset code bundler

Can’t use aws-lambda-nodejs’ capabilities in Lambda@Edge.

Use Case

If you want to use a NodeJS lambda in edge, you need to bundle the code by yourself. It’d be ideal to export the esbuild bundling functionality so anybody can create the AssetCode with esbuild and use it on any other lambda functions such as Lambda@Edge.

Proposed Solution

Just exporting the class Bundling in @aws-cdk/aws-lambda-nodejs would be enough. As a workaround, I did this, which is heavily based on the current implementation but uses esbuild’s JS API:

import * as lambda from "@aws-cdk/aws-lambda";
import * as cdk from "@aws-cdk/core";
import * as esbuild from "esbuild";
import findUp from "find-up";
import * as path from "path";

const findDepsLockFilePath = (input: string) => {
  const lockFilePath = findUp.sync(["package-lock.json", "yarn.lock"], {
    cwd: input,
  });

  if (!lockFilePath) {
    throw new Error("Couldn't find a lock file (package-lock.json or yarn.lock)");
  }

  return lockFilePath;
};

/**
 * Converts a Lambda runtime to an esbuild node target.
 */
function toTarget(runtime: lambda.Runtime): string {
  const match = runtime.name.match(/nodejs(\d+)/);

  if (!match) throw new Error("Cannot extract version from runtime.");

  return `node${match[1]}`;
}

export interface EsbuildBundlingProps {
  input: string;
  runtime: lambda.Runtime;
  external?: string[];
  define?: {
    [key: string]: string;
  };
}

export class EsbuildBundling {
  public static bundle(options: EsbuildBundlingProps): lambda.AssetCode {
    const depsLockFilePath = findDepsLockFilePath(options.input);

    return lambda.Code.fromAsset(path.dirname(depsLockFilePath), {
      assetHashType: cdk.AssetHashType.OUTPUT,
      bundling: new EsbuildBundling(options),
    });
  }

  public readonly image: cdk.DockerImage;

  public readonly local: cdk.ILocalBundling;

  constructor(private readonly props: EsbuildBundlingProps) {
    this.image = cdk.DockerImage.fromRegistry("dummy");
    this.local = {
      tryBundle(outputDir) {
        console.log({ outputDir, input: props.input });
        esbuild.buildSync({
          entryPoints: [props.input],
          bundle: true,
          platform: "node",
          target: toTarget(props.runtime),
          outfile: `${outputDir}/index.js`,
          external: ["aws-sdk", ...(props.external || [])],
          define: props.define,
          // minify: true,
        });
        return true;
      },
    };
  }
}

Other

• 👋 I may be able to implement this feature request
• ⚠️ This feature might incur a breaking change

---

This is a 🚀 Feature Request

[eladb]

I am unassigning and marking this issue as p2, which means that we are unable to work on this immediately.

We use +1s to help prioritize our work, and are happy to revaluate this issue based on community feedback. You can reach out to the cdk.dev community on Slack to solicit support for reprioritization.

[hugomallet]

I don’t really understand why it’s low priority. How do you guys do with v2 ? Any workaround ? In the meantime can you at least fix this please ? https://github.com/aws/aws-cdk/issues/15661#issuecomment-1020356712 Thanks