A Simple PhantomJS Screenshot Server

This is a simple screenshot server running over http. You append a url (a urlencoded url) to the server and it returns a PNG image of the screenshot. It’s a simple implementation and not very scalable because of threading limits in phantomjs. But it could be modified to be much more robust and is a great starting point if you’re interested in improving.

Here are some example urls how it works.

http://yourserver:8001/http%3A%2F%2Fphantomjs.org%2Fapi%2Fwebpage%2Fproperty%2Fclip-rect.html
http://yourserver:8001/https%3A%2F%2Fbitbook.io%2F

First step is to install

Install NodeJS and PhantomJS on Ubuntu

apt-get install npm nodejs-legacy nodejs
npm -g install phantomjs-prebuilt
npm -g update phantomjs-prebuilt

Save the code out to a file named server.js, then you can run it with

phantomjs server.js 8001

The Code

"use strict";
var port,
	server,
	service,
	system = require('system'),
	page,
	address,
	output,
	width;


if (system.args.length !== 2) {

	console.log('Usage: server.js <portnumber>');
	phantom.exit(1);

} else {
	port = system.args[1];
	server = require('webserver').create();

	service = server.listen(port, function (request, response) {

		// logging, comment out if you dont want any
		console.log('Request at ' + new Date());
		console.log(JSON.stringify(request, null, 4));

		//url request comes in like this - url encoded url after the 8001/
		//curl http://127.0.0.1:8001/URL_ENCODED_URL_HERE;
		//curl http://127.0.0.1:8001/http%3A%2F%2Fbitbook.io/;

		//remove 1st slash on url
		var url = request.url.substring(1, request.url.length);

		page = require('webpage').create();
		page.viewportSize = {width: 1200, height: 900};//max ever canvas
		page.settings.userAgent = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.120 Safari/537.36';

		page.open(url, function (status) {

			if (status !== 'success') {

				page.close();
				response.statusCode = 500;
				response.write('error: url no load');
				response.close();
				console.log('Unable to load the address');

			} else {
//				removed timeout
//				window.setTimeout(function () {
					// phantomjs doesnt set a background if page has none, so force it if none
					page.evaluate(function() {
						var style = document.createElement('style'),
							text = document.createTextNode('body { background: #fff }');
						style.setAttribute('type', 'text/css');
						style.appendChild(text);
						document.head.insertBefore(style, document.head.firstChild);
					});

					var base64 = page.renderBase64('PNG');

					response.statusCode = 200;
					response.setHeader("Content-Type", "image/png");
					response.setEncoding('binary');
					response.write(atob(base64));
					response.close();

//				}, 21500);

			}
		});

	});


	if (service) {
		console.log('Web server running on port ' + port);
	} else {
		console.log('Error: Could not create web server listening on port ' + port);
		phantom.exit();
	}


}

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