Running Pyvirtualdisplay on WSGI

Question

I am trying to run pyvirtualdisplay as part of a WSGI app. I have Xfvb installed, my 000-default.conf file:

<VirtualHost *:80>
    # The ServerName directive sets the request scheme, hostname and port that
    # the server uses to identify itself. This is used when creating
    # redirection URLs. In the context of virtual hosts, the ServerName
    # specifies what hostname must appear in the request's Host: header to
    # match this virtual host. For the default virtual host (this file) this
    # value is not decisive as it is used as a last resort host regardless.
    # However, you must set it for any further virtual host explicitly.
    #ServerName www.example.com

    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html
    WSGIDaemonProcess flaskapp user=ubuntu threads=5
    WSGIScriptAlias / /var/www/html/flaskapp/flaskapp.wsgi
    <Directory flaskapp>
        WSGIProcessGroup flaskapp
        WSGIApplicationGroup %{GLOBAL}
        Require all granted
    </Directory>
    # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
    # error, crit, alert, emerg.
    # It is also possible to configure the loglevel for particular
    # modules, e.g.
    #LogLevel info ssl:warn

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    # For most configuration files from conf-available/, which are
    # enabled or disabled at a global level, it is possible to
    # include a line for only one particular virtual host. For example the
    # following line enables the CGI configuration for this host only
    # after it has been globally disabled with "a2disconf".
    #Include conf-available/serve-cgi-bin.conf
</VirtualHost>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet

my code :

from flask import Flask
from pyvirtualdisplay import Display

app = Flask(__name__)

@app.route('/')
def crawl_sc():
    display = Display(visible=0, size=(1920, 999))
    display.start()
    display.stop()
    return 'ran'
if __name__ == '__main__':
    app.run(debug=True)

when I run this through the WSGI it just continually loads, but there are no errors in the error.log. I am using an AWS EC2 with Ubuntu 16.04 and Apache 2.4.18, mod_wsgi 4.6.4 & Python 3.6.

Answer 1

So after reaching out to the owner of the git repo for mod_wsgi I figured out that i had been running it in embedded mode with the above 000-default.conf. In embedded it does not use the main interpretor. To solve this I changed the above to:

 <Directory /var/www/html/flaskapp>
    WSGIProcessGroup flaskapp
    WSGIApplicationGroup %{GLOBAL}
    Require all granted
 </Directory>

This used the main interpreter and now the script runs :)