Serverless HTML to PDF with AWS Lambda + Chrome

payload.json

{
  "html": "<p>Hello, world!</p>"
}

web2pdf.js

const chromium = require('chrome-aws-lambda');
const fs = require('fs');

exports.handler = async (event, context, callback) => {
  let result = null;
  let browser = null;

  try {
    browser = await chromium.puppeteer.launch({
      args: chromium.args,
      defaultViewport: chromium.defaultViewport,
      executablePath: await chromium.executablePath,
      headless: chromium.headless,
      ignoreHTTPSErrors: true,
    });
    
    // this guarantees that the file won't conflict with other files
    // that could possibly be generated at the same time
    //
    // this is assuming of course that the file system in lambda
    // is shared and that we don't want name conflicts to occur
    // if the function is invoked at the same time
    let fileName = Date.now(); 
    
    fs.writeFileSync(`/tmp/${fileName}.html`, event.html);

    const page = await browser.newPage();

    await page.goto(`file:///tmp/${fileName}.html`);
    
    const pdf = await page.pdf({
      displayHeaderFooter: false,
      printBackground: true,
      margin: {
        'top': '0.4in',
        'bottom': '0.4in',
        'left': '0.4in',
        'right': '0.4in'
      }
    });

    result = pdf.toString('base64');
  } catch (error) {
    return callback(error);
  } finally {
    if (browser !== null) {
      await browser.close();
    }
  }

  return callback(null, result);
};