Lighthouse-lambda NPM

joytocode/lighthouse-lambda

Run Google Chrome Lighthouse on AWS Lambda.

Versions

Since version 2.x, lighthouse-lambda has the same major version of lighthouse. For example, lighthouse-lambda 3.x will use lighthouse 3.x.

This README is for version 3.x. To see older versions, visit:

2.x: https://github.com/joytocode/lighthouse-lambda/tree/archived-v2

Installation

$ npm install lighthouse-lambda --save

Lambda function

// index.js

const createLighthouse = require('lighthouse-lambda')

exports.handler = function (event, context, callback) {
  Promise.resolve()
    .then(() => createLighthouse('https://example.com', { logLevel: 'info' }))
    .then(({ chrome, start }) => {
      return start()
        .then((results) => {
          // Do something with `results`
          return chrome.kill().then(() => callback(null))
        })
        .catch((error) => {
          // Handle errors when running Lighthouse
          return chrome.kill().then(() => callback(error))
        })
    })
    // Handle other errors
    .catch(callback)
}

Testing locally

You can use docker-lambda to test your Lambda function locally.

$ docker run --rm -v "$PWD":/var/task lambci/lambda:nodejs8.10 index.handler

Deployment

You can use docker-lambda to install dependencies and pack your Lambda function.

$ docker run --rm -v "$PWD":/var/task lambci/lambda:build-nodejs8.10 bash -c "rm -rf node_modules && npm install"

$ docker run --rm -v "$PWD":/var/task lambci/lambda:build-nodejs8.10 bash -c "rm -f *.zip && zip lambda.zip -r node_modules index.js package.json"

The file will be big (at least 75MB), so you need to upload it to S3 then deploy to Lambda from S3.
You should allocate at least 512 MB memory and 15 seconds timeout to the function.

API

createLighthouse(url, options, config)

Same parameters as Using Lighthouse programmatically.

Returns a Promise of an Object with the following fields:

chrome: an instance of chromeLauncher.launch(), remember to call chrome.kill() in the end.
log: an instance of lighthouse-logger (only if you set options.logLevel).
start(): a function to start the scan which returns a Promise of Lighthouse results.