Setting up Flask and Apache on Ubuntu 18.04 Server

Setup Python3 Environment

First, update apt-get.

$ sudo apt-get update

Python3 installed.

$ sudo apt-get install python3-pip

Get virtualenv.

$ pip3 install virtualenv

Create the project folder.

$ mkdir flaskproject

Set up the virtual environment.

$ cd flaskproject
$ virtualenv venv

Activate the environment (use deactivate to exit the environment).

$ . venv/bin/activate

Setup Flask

Install Flask

$ pip install Flask

Create the Flask file. For now, we will use a basic sample file and call it app.py

$ vi app.py

Paste the following code in.

from flask import Flask
app = Flask(__name__)

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

if __name__ == "__main__":
    app.run()

Setup Apache

Install mod_wsgi, make sure to have '-py3' at the end of libapache2-mod-wsgi-py3 or the runtime will default to Python2.7

$ sudo apt-get install apache2 libapache2-mod-wsgi-py3

Create a wsgi file.

$ vi app.wsgi

Paste the following code in.

activate_this = '/home/ubuntu/flaskproject/venv/bin/activate_this.py'
with open(activate_this) as f:
 exec(f.read(), dict(__file__=activate_this))

import sys
import logging

logging.basicConfig(stream=sys.stderr)
sys.path.insert(0,"/var/www/html/flaskproject/")

from app import app as application

Create a symlink so that the project directory appears in /var/www/html

$ sudo ln -sT ~/flaskproject /var/www/html/flaskproject

Enable wsgi.

$ sudo a2enmod wsgi

Configure apache (you will need to sudo to edit the file)

$ sudo vi /etc/apache2/sites-enabled/000-default.conf

Paste this in right after the line with DocumentRoot /var/www/html

WSGIDaemonProcess flaskproject threads=5
WSGIScriptAlias / /var/www/html/flaskproject/app.wsgi

<Directory flaskproject>
 WSGIProcessGroup flaskproject
 WSGIApplicationGroup %{GLOBAL}
 Order deny,allow
 Allow from all
</Directory>

Restart the Server
 service apache2 restart