Getting Flask to use Python3 (Apache/mod_wsgi)

Question

I\'ve got a basic \"hello world\" Flask app running.

I\'m on Ubuntu 14.04, using Apache 2.4. I\'ve installed mod_wsgi.

I\'ve created a ~/web/piFlask/

Answer 1

I started running python3.5.2 with flask 0.12 in a venv on a Ubuntu 16.04 (virtual machine).

@Graham pointed out activating the the venv from the WSGI script file is not the preferred way. More info here: http://modwsgi.readthedocs.io/en/develop/user-guides/virtual-environments.html

Just for anyone else looking for info on this I'm putting all your steps together:
Note: my app name is blazing, path ~/jan/blazing. Replace them with your own.

sudo apt install python3-pip

sudo apt-get install python3-venv
python3 -m venv ~/blazing/venv
source /home/jan/blazing/venv/bin/activate

pip3 install --upgrade pip    
pip3 install Flask

sudo apt-get install apache2-dev
(venv) pip3 install mod_wsgi
(venv) sudo venv3/bin/mod_wsgi-express install-module

OUTPUT:
LoadModule wsgi_module "/usr/lib/apache2/modules/mod_wsgi-py35.cpython-35m-x86_64-linux-gnu.so"
WSGIPythonHome "/home/jan/blazing/venv"

sudo vim /etc/apache2/mods-available/wsgi_express.load

ADD: LoadModule wsgi_module "/usr/lib/apache2/modules/mod_wsgi-py35.cpython-35m-x86_64-linux-gnu.so"

sudo vim /etc/apache2/mods-available/wsgi_express.conf

ADD:

WSGIPythonHome "/home/jan/blazing/venv"
WSGIPythonPath /home/jan/blazing/venv/lib/python3.x/site-packages

then

sudo a2enmod wsgi_express

vim /home/jan/blazing/project/flaskapp.wsgi

ADD:

import os, sys

PROJECT_DIR = '/home/jan/blazing' sys.path.insert(0, PROJECT_DIR)

activate_this = os.path.join( PROJECT_DIR, 'venv/bin', 'activate_this.py' )
with open(activate_this) as file_:
    exec(file_.read(), dict(__file__=activate_this)


from piFlask import app as application application.debug = True

and

vim /etc/apache2/sites-available/flask.conf

ADD:

WSGIDaemonProcess flaskProcess user=www-data group=www-data threads=5
WSGIScriptAlias /flask /home/jan/blazing/project/flaskapp.wsgi

ErrorLog ${APACHE_LOG_DIR}/error_flask.log #you can see the errors here..
CustomLog ${APACHE_LOG_DIR}/access_flask.log combined


    WSGIProcessGroup flaskProcess
    WSGIApplicationGroup %{GLOBAL}
    Require all granted

Or if you have other sites running and would like to have flask as one of the Virtual hosts, you can use this conf file:

    ServerName flask.ubuntuws
    ErrorLog ${APACHE_LOG_DIR}/error_flask.log
    CustomLog ${APACHE_LOG_DIR}/access_flask.log combined

    WSGIDaemonProcess flaskProcess user=www-data group=www-data threads=5
    WSGIScriptAlias / /home/jan/blazing/project/flaskapp.wsgi

    
        WSGIProcessGroup flaskProcess
        WSGIApplicationGroup %{GLOBAL}
        Require all granted
    

and make sure your PROJECT_DIR in flaskapp.wsgi points to your PROJECT_NAME.py.
enable the virtual site and reload apache:

lastly:

sudo a2ensite flask.conf
sudo service apache2 reload