AWS Lambda NodeJS Custom Runtime

AWS Lambda runtime API implemented in Node.js.

This library can be used to implement

• a custom runtime Lambda layer for any Node.js version
• a container runtime with Node.js as the execution environment
• to test your Node.js lambda functions locally

Goals

• Provide a robust custom Node.js execution environment
• Make sure that it's compatible with the official node12.x and node14.x environments

How to install?

npm install aws-lambda-node-runtime --save

How to use it?

The following examples assume that

• your lambda function code is in the /var/task folder.
• There's /var/task/index.js file that exports the Lambda handler function

You need to set the following environment variables

export LAMBDA_TASK_ROOT=/var/task

export AWS_LAMBDA_FUNCTION_NAME=my-function-name
export AWS_LAMBDA_FUNCTION_VERSION=v1
export AWS_LAMBDA_FUNCTION_MEMORY_SIZE=128
export AWS_LAMBDA_LOG_GROUP_NAME=test-log-group-name
export AWS_LAMBDA_LOG_STREAM_NAME=test-log-stream-name

Use it from your JS code

const runtime = require('aws-lambda-node-runtime');

const done = (err) => {
  if (err) {
    console.warn('Runtime exiting due to an error', err)
  }
}

process.env._HANDLER = 'index.handler';

console.warn('Runtime starting...')
runtime(done);

Execute it directly from a script or command line

# The follow command assumes that there's /path/to/your/app/index.js file that exports the `handler` functions
npx aws-lambda-node-runtime index.handler

Integration tests

Execute the Lambda API test server

npx ts-node runtime-api/server

In another terminal execute the runtime with hello.js as the Lambda source

npx ts-node integration/test