How to run Headless Chrome in Azure Cloud Service or Azure Functions?

Question

I am trying to use Headless Chrome to generate a PDF file from a complex HTML file (contains images, SVGs, etc.). I am able to use wkhtmltopdf.exe on Cloud Service (Windows) to generate simple PDF file, but I really need Chrome to produce PDFs as close as possible to the HTML + SVG + Image.

I was hoping to be able to run Headless Chrome in Azure Cloud Service or Azure Functions, but I cannot get it to work. I suppose this is due to restrictions on GDI. I was able to run my code and Headless Chrome in the Azure Emulator on my own machine, but once it is deployed nothing works.

Below is the code I am currently running in Azure Functions (for Windows). I am using Puppeteer to take a screenshot of example.com. If I can get this to work, I suppose that generating PDF will become easy.

const fs = require('fs');
const path = require('path');
const puppeteer = require('puppeteer');
const os = require('os');

module.exports = function (context, req) {
    function failureCallback(error) {
        context.log("--> Failure = '" + error + "'");
    }

    const chromeDir = path.normalize(__dirname + "/../node_modules/puppeteer/.local-chromium/win64-508693/chrome-win32/chrome.exe");
    context.log("--> Chrome Path = " + chromeDir);

    const dir = path.join(os.tmpdir(), '/screenshots');

    if (!fs.existsSync(dir)){
        fs.mkdirSync(dir);
    }

    const screenshotPath = path.join(dir, "example.png");
    context.log("--> Path = " + screenshotPath);

    let browser, page;
    puppeteer.launch({ executablePath: chromeDir, headless: true, args: [ '--no-sandbox', '--single-process', '--disable-gpu' ] })
        .then(b => {
            context.log("----> 1");
            browser = b;
            return browser.newPage();
        }, failureCallback)
        .then(p => {
            context.log("----> 2");
            page = p;
            return p.goto('https://www.example.com');
        }, failureCallback)
        .then(response => {
            context.log("----> 3");
            return page.screenshot({path: screenshotPath, fullPage: true});  
        }, failureCallback)
        .then(r => {
            browser.close();

            context.res = {
                body: "Done!"
            };

            context.done();            
        }, failureCallback);
};

Below is the log when trying to execute the script.

2017-12-18T04:32:05  Welcome, you are now connected to log-streaming service.
2017-12-18T04:33:05  No new trace in the past 1 min(s).
2017-12-18T04:33:11.400 Function started (Id=89b31468-8a5d-43cd-832f-b641216dffc0)
2017-12-18T04:33:20.578 JavaScript HTTP trigger function processed a request.
2017-12-18T04:33:20.578 --> Chrome Path D:\home\site\wwwroot\node_modules\puppeteer\.local-chromium\win64-508693\chrome-win32\chrome.exe
2017-12-18T04:33:20.578 --> Path = D:\local\Temp\screenshots\example.png
2017-12-18T04:33:20.965 --> Failure = 'Error: spawn UNKNOWN'
2017-12-18T04:33:20.965 ----> 2

The error "Failure = 'Error: spawn UNKNOWN'" is not clear. I made sure that the path I am using is correct using Kudu and PowerShell.

I am looking for a way to run Chrome on Azure Cloud Service and/or Azure Functions (for Windows - in order to use my existing App Service plan). Anybody has also attempted to run Headless Chrome in Azure? I am open to any ideas which would help me to get this script to work?

Answer 1

I would recommend to use https://www.browserless.io/ so you don't have to run the chrome.exe in the app service.

Replace puppeteer.launch with puppeteer.connect

const browser = await puppeteer.connect({
  browserWSEndpoint: 'wss://chrome.browserless.io/'
});