PDF Generation Server with Puppeteer

A node.js server to create a PDF from HTML using Puppeteer. It can be used by the TestArchiveCreator plugin for ILIAS.

Direct Installation on a Server

Create a user account that should be used for running the server:

useradd -rm -G audio,video tarc-pdf

Log in as that user and clone this repository. Go to the cloned directory and install puppeteer:

npm install puppeteer

To run the service go to the cloned directory an execute:

node service.js

It should show you this message:

Server running on port 8080

You should put this service behind a reverse proxy to call it with https from outside.

Installation as a Docker Container

Log in as a user that is able to build and run docker images. Clone this repository. Go to the cloned repository and build the container:

docker build -t tarc-pdf .

Run the container:

docker run -p 8080:8080 tarc-pdf

Ther service should then be avalilable on port 8080 of your docker host. You should put it behind a reverse proxy to call it with https from outside.

Usage in ILIAS

Open the configuration of the TestArchiveCreator in your ILIAS installation.

Choose "Puppeteer on Separate Server" at PDF generation and enter the URL of your PDF generation server, e.g. for a server running on your host:

http://localhost:8080

Create an archive of a test. Depending on what you configured as content, it should contain PDF files for the questions and answers of participants.

ILIAS Configuration

The server receives the pure HTML code of a page that should be rendered. It needs to load asset files (styles, scripts and images) from ILIAS afterwards.

• In a production environment make sure that the URL of your ILIAS installation can be accessed by the PDF generation server.

• A docker container on a local development machine will not be able to load the images from a URL with localhost. Look up the IP address of your local web server, e.g. with the ifconfig command and...

  • ... use it for your ILIAS address in the browser when you generate the archive interactively,
  • ... configure it as http_path the [server] section of your ilias.ini.php when you generate the archive in a cron hob.

Implementation

The service is called with a POST request and returns the generated PDF as inline content. The POST must be delivered as content-type: application/x-www-form-urlencoded.

POST Field	Content
html	The HTML content to be rendered
format	e.g. 'A4'
landscape	'0' or '1'
headerTemplate	html code of the template for the header
footerTemplate	html code of the template for the footer

see https://pptr.dev/api/puppeteer.pdfoptions for details.

Acknowledgements

The implementation adapts examples from:

• https://apitemplate.io/blog/tips-for-generating-pdfs-with-puppeteer/
• https://stackoverflow.com/questions/4295782/how-to-process-post-data-in-node-js
• https://blog.apify.com/puppeteer-docker/