AWS Lambda HTML to PDF

The Nightmare is Over

Rendering PDF in Lambda took longer than expected. Tutorials exist in both AWS Lambda and the Serverless Framework. Most do not work, though. The wktohtml and phantomJS libraries in nodeJS are problematic. They don't fully support NodeJS 12.X. So fear no more, some people have figured it out.

Headless Chromium to the Rescue

The key is to use the chrome-aws-lambda tooling. The catch is you must install a Lambda layer (instructions exist in the Readme). Serverless provides an easy way to apply layers. You can always manually add one in the Lambda AWS dashboard. Once there, you can write a Lambda function to load a headless browser to perform work.

	const chromium = require('chrome-aws-lambda');
	module.exports.handler = async (event) => {
	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();
	await page.goto('https://google.com');
	const pdf = await page.pdf({format: 'A4'});
	return {
	statusCode: 200,
	headers: {
	"Content-type": "application/pdf",
	"accept-ranges": "bytes",
	'Access-Control-Allow-Origin': '*',
	},
	body: pdf.toString('base64'),
	isBase64Encoded : true
	}
	} finally {
	if (browser !== null) {
	await browser.close();
	}
	}
	};

view raw serverless_print_api.js hosted with ❤ by GitHub

I hope this is helpful to you! Share your thoughts in the comments!