Generate a PDF in AWS Lambda with NodeJS and Puppeteer

"dependencies": {
  "chrome-aws-lambda": "1.18.1",
  "knex": "0.18.3",
  "pg": "7.11.0",
  "pg-hstore": "2.3.2",
  "pug": "2.0.4",
  "puppeteer-core": "1.18.1",
}
"devDependencies": {
    "serverless": "1.40.0",
    "serverless-apigw-binary": "0.4.4",
    "serverless-offline": "4.9.4",
  }

'use strict'
const chromium = require('chrome-aws-lambda')
const pug = require('pug')
const fs = require('fs')
const path = require('path')

const knex = require('./src/db')

module.exports.pdf = async (event, context) => {
  const yearMonth = ((event || {}).pathParameters || {}).yearMonth || ''
  const year = yearMonth.length == 7 && yearMonth.substring(0, 4)
  const month = yearMonth.length == 7 && yearMonth.substring(5, 6)

  // Select a date
  const selDate = new Date(year, month)
  const filter = {
    month: selDate.toLocaleString('en', { month: 'long' }),
    year: selDate.getFullYear()
  }


  // 1. Load database data wiht Knex TODO
  const result = await knex
    .select()
    .from('sales')
    .where({
      year: filter.year,
      month: selDate.getMonth() + 1
    })

  // 2. Create html
  const template = pug.compileFile('./src/template.pug')
  const html = template({ ...filter, result })

  // 3. Open puppeteer
  let browser = null
  try {
    browser = await chromium.puppeteer.launch({
      args: chromium.args,
      defaultViewport: chromium.defaultViewport,
      executablePath: await chromium.executablePath,
      headless: chromium.headless
    })

    const page = await browser.newPage()
    page.setContent(html)

    // 4. Create pdf file with puppeteer
    const pdf = await page.pdf({
      format: 'A4',
      printBackground: true,
      margin: { top: '1cm', right: '1cm', bottom: '1cm', left: '1cm' }
    })

    // 5. Return PDf as base64 string
    const response = {
      headers: {
        'Content-type': 'application/pdf',
        'content-disposition': 'attachment; filename=test.pdf'
      },
      statusCode: 200,
      body: pdf.toString('base64'),
      isBase64Encoded: true
    }
    context.succeed(response)
  } catch (error) {
    return context.fail(error)
  } finally {
    if (browser !== null) {
      await browser.close()
    }
  }
}

service:
  name: PDF

plugins:
  - serverless-offline
  - serverless-apigw-binary

provider:
  name: aws
  runtime: nodejs8.10
  region: eu-central-1
  stage: ${opt:stage, 'development'}
  environment:
    ENV: ${self:provider.stage}

custom:
  apigwBinary:
    types:
      - '*/*'

functions:
  pdf:
    handler: pdf.pdf
    events:
      - http:
          path: pdf
          method: get
          cors: true