Driverless Printing and Scanning REST API

A simple REST API for scanning (eSCL) to JPEG or PDF and printing (with IPP or CUPS) a PDF from anywhere (eg. via a webbrowser) with ease

Motivation

I could not find a simple web app running on a server that could initiate a printing and scanning process from other machines without installing anything on the client machines. So I had to write my own on top of almost 10 years old standards (IPP and eSCL)... Et voilà!

Motto:

"So tonight I'm gonna print and scan like it's nineteen ninety-nine!" (refering to Prince)

Requirements

• Python 3
• A server (ipptool in PATH or CUPS with the printer driver properly installed)
• An IPP capable printer and/or an eSCL capable scanner
• A WSGI server

Example setup

1. Setup your printer in CUPS on the server (if the CUPS option is chosen)
2. Make a virtual environment: sudo virtualenv -p python3 /var/www/driverless_print_and_scan_venv
3. Clone the repository: sudo git clone https://github.com/dlazesz/driverless_print_and_scan_venv/driverless-print-and-scan
4. Modify the PRINTER variable in printrest.py to the appropriate name and SCANNER_IP variable in scanrest.py
5. Install requirements in the virtual environment source /var/www/driverless_print_and_scan_venv/bin/activate; pip install -r requirements.txt
6. Set user permissions: sudo chown -R user:www-data /var/www/driverless_print_and_scan_venv
7. Create the WSGI file:

   from printrest import app
   
   if __name__ == '__main__':
       app.run()

8. Setup a WSGI server. I do not recommend uwsgi because of its numerous quirks
   • Example in apache:

     <VirtualHost *:80>
     
         WSGIDaemonProcess printrest threads=5 python-path=/var/www/printrest_venv/lib/python3.5/site-packages
         WSGIScriptAlias /print /var/www/printrest_venv/printREST/print.wsgi
     
         <Directory /var/www/printrest_venv/printREST>
             WSGIProcessGroup printrest
             WSGIApplicationGroup %{GLOBAL}
             Order deny,allow
             Allow from all
         </Directory>
     </VirtualHost>

   • Example in Gunicorn + Nginx + Systemd:
     • Create Systemd unit sudo mcedit /etc/systemd/system/printREST.service with the following content:

       [Unit]
       Description=Gunicorn instance to serve printREST
       After=network.target
       
       [Service]
       User=sammy
       Group=www-data
       WorkingDirectory=/var/www/driverless_print_and_scan_venv/driverless-print-and-scan
       Environment="PATH=/var/www/driverless_print_and_scan_venv/bin"
       ExecStart=/var/www/driverless_print_and_scan_venv/bin/gunicorn --workers 2 --bind unix:printREST.sock -m 007 wsgi:app
       
       [Install]
       WantedBy=multi-user.target

     • Start and enable the Systemd service sudo systemctl start printREST && sudo systemctl enable printREST
     • Add location to Nginx:

       location /print {
           # Do not forget to add password protection!
           include proxy_params;
           proxy_pass http://unix:/var/www/driverless_print_and_scan_venv/driverless-print-and-scan/printREST.sock;
           client_max_body_size 100M;  # 1MB is the default upload limit! 
       }
       

     • Restart Nginx sudo systemctl restart nginx
9. Navigate to http://yourserver.com/print
10. Print from anywhere to your printer without installing drivers
11. Profit!

The same goes for the scanner setup

License

This program is licensed under the LGPL 3.0 license.