Wkhtmltopdf (pdfkit) - QXcbConnection: Could not connect to display

Question

I'm working on a Django project where we generate PDF files from HTML template. I use django-pdfkit to render PDF.

On my Ubuntu 16.04 everything works correctly but when I deploy the project on DigitalOcean Ubuntu 16.04 server, it raises error:

IOError at /render/doklad/ wkhtmltopdf exited with non-zero code -6. error:

QXcbConnection: Could not connect to display

I tried to install

sudo apt-get install libxrender1 fontconfig xvfb

Set WKHTMLTOPDF_BIN variable to correct path.

Changed gunicorn user to root.

pip install wkhtmltopdf

Nothing helped, do you know what I can do to solve this?

EDIT:

I've found out that if I do this command as a root, it works correctly:

wkhtmltopdf http://www.google.com google.pdf

But the problem is if I run the command using django user. It returns the same thing:

QXcbConnection: Could not connect to display 
Aborted (core dumped)

So I tried to change gunicorn.service so gunicorn is running under root instead of django but it didn't help.

http://mypage/render/doklad/?id=1 

returns the same error.

The error seems to be raised in this file:

https://github.com/JazzCore/python-pdfkit/blob/master/pdfkit/pdfkit.py

And this is a traceback:

Aug 25 04:42:46 homeit-generator-faktur-beta gunicorn[29032]:  - - [25/Aug/2017:04:42:46 +0000] "GET / HTTP/1.0" 302 - "-" "Mozilla/5.0"
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]: Internal Server Error: /render/doklad/
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]: Traceback (most recent call last):
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/django/cor
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     response = get_response(request)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/django/cor
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     response = self.process_exception_by_middleware(e, request)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/django/cor
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     response = wrapped_callback(request, *callback_args, **callback_kwargs)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/django/vie
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     return self.dispatch(request, *args, **kwargs)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/django/vie
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     return handler(request, *args, **kwargs)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/dashboard/views.py", line 186, in get
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     return super(DokladToPdf, self).get(*args, **kwargs)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/django_pd
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     content = self.render_pdf(*args, **kwargs)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/django_pd
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     pdf = pdfkit.from_string(html, False, options, **kwargs)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/pdfkit/ap
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     return r.to_pdf(output_path)
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:   File "/home/django/homeit/homeitvenv/local/lib/python2.7/site-packages/pdfkit/pd
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:     raise IOError("wkhtmltopdf exited with non-zero code {0}. error:\n{1}".format(
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]: IOError: wkhtmltopdf exited with non-zero code -6. error:
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]: QXcbConnection: Could not connect to display
Aug 25 06:05:55 homeit-generator-faktur-beta gunicorn[29032]:  - - [25/Aug/2017:06:05:55 +0000] "GET /render/doklad/?id=1 HTTP/1.0" 500 108058 "

Answer 1

Are you running your commmand through xvfb-run?

In your calling code you may need to replace straight-up calls to wkhtmltopdf with something more like this:

xvfb-run -a -s "-screen 0 1024x768x16" /path/to/bin/wkhtmltopdf