Node.js 10.x and 12.x for AWS Lambda

A custom runtime for AWS Lambda to execute functions in Node.js 10.x or 12.x

Getting Started

Save as index.js:

exports.handler = async(event, context) => {
  console.log(`Hi from Node.js ${process.version} on Lambda!`)
  console.log(`There is ${context.getRemainingTimeInMillis()}ms remaining`)
  return event
}

Then bundle up into a zipfile – this is your function bundle:

zip -yr lambda.zip index.js  # add node_modules too if you have any

Create a new Lambda function and choose the custom runtime option.

Select your lambda.zip as the "Function code" and make the handler "index.handler".

Then click on Layers and choose "Add a layer", and "Provide a layer version ARN" and enter the following ARN:

arn:aws:lambda:us-east-1:553035198032:layer:nodejs12:41

Or use this link and pick your function from the "Function name" auto-suggest.

Then save your lambda and test it with a test event!

Current Version ARNs

Previous Version ARNs

Things to be aware of

• This is a no-batteries-included runtime – you'll need to zip up any node_modules dependencies, including aws-sdk with your lambda function
• It does not monkeypatch console.log, console.error, etc functions to add extra timestamps and request IDs to each line you log as the official runtimes do. I believe this leads to fewer surprises and cleaner logs that are easier to parse by various tools – but if you're relying on this behaviour you'll need to add these fields yourself.
• Cold start overhead of ~240ms for Node.js 10.x and ~260ms for 12.x – this is due to Node.js' increasingly slow startup time, but they're working on it!