Running a Flask App under Apache with Plesk

Having no end of problems running Flask under Apache using Plesk. Really been scratching my head with this one.

As I am using Plesk, I realise that I need to use the vhosts conf files under /var/www/vhosts instead of the virtualhost config (sitting under the typical "sites-available" directory in Apache).

When I attempt to run my Flask App, I receive the error within my Apache error log:

Timeout when reading response headers from daemon process 'unifica': /apps/start.wsgi

My wsgi application file lives here:

/apps/start.wsgi

and reads as follows:

activate_this = '/apps/unifica/venv/bin/activate_this.py'
execfile(activate_this, dict(__file__=activate_this))
from unifica import app as application

As you will notice. I am using a Virtual Environment. Subsequently, my actual application lives here:

apps/unifica/main.py

and reads as follows:

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return 'Hello, World!'

if __name__ == "__main__":
    app.run(host='0.0.0.0')

As my site is secured over ssl; I have the following two vhost configurations:

vhost.conf and vhost_ssl.conf

My vhost.conf contains:

RewriteEngine On
RewriteCond %{HTTPS} !on
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

(to redirect insecure requests)

My vhost_ssl.conf contains:

WSGIDaemonProcess unifica user=flaskuser group=flaskgroup threads=5
WSGIScriptAlias / /apps/start.wsgi

<Directory /apps >
    WSGIProcessGroup unifica
    WSGIApplicationGroup %{GLOBAL}
    Require all granted
    WSGIScriptReloading On
</Directory>

flaskuser exists and belongs to flaskgroup. I have assigned 0755 rights to flaskuser (as the owner) on the /apps/ folder.

Any idea where I am going wrong here? I presume I have made a fairly obvious mistake somewhere...