How to Deploying Flask Application on Ubuntu (Apache+WSGI)

Deploying a Flask application on Ubuntu using Apache and mod_wsgi involves several steps. Here’s a step-by-step guide:

Step 1: Install Apache and mod_wsgi

First, you need to install Apache and mod_wsgi. You can do this using the following commands:

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

Step 2: Install Flask

Next, you need to install Flask. You can do this using pip:

sudo apt-get install python3-pip
pip3 install flask

Step 3: Create Your Flask Application

Now you can create your Flask application. For example, you might create a directory for your application and a simple “Hello, World!” application like this:

mkdir ~/myflaskapp
nano ~/myflaskapp/app.py

In the app.py file, you might write something like this:

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello, World!"

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

Step 4: Configure Apache

Next, you need to configure Apache to serve your Flask application. You can do this by creating a new configuration file in the /etc/apache2/sites-available/ directory:

sudo nano /etc/apache2/sites-available/myflaskapp.conf

In this file, you might write something like this:

<VirtualHost *:80>
    ServerName mydomain.com
    ServerAdmin admin@mydomain.com
    WSGIScriptAlias / /var/www/myflaskapp/myflaskapp.wsgi
    <Directory /var/www/myflaskapp/>
        Order allow,deny
        Allow from all
    </Directory>
    ErrorLog ${APACHE_LOG_DIR}/error.log
    LogLevel warn
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

Step 5: Create the WSGI File

Next, you need to create the WSGI file that Apache will use to serve your Flask application. You can do this with the following commands:

mkdir /var/www/myflaskapp
nano /var/www/myflaskapp/myflaskapp.wsgi

In the myflaskapp.wsgi file, you might write something like this:

import sys
sys.path.insert(0, '/home/username/myflaskapp')

from app import app as application

Step 6: Enable the Site

Finally, you can enable the site and restart Apache to start serving your Flask application:

sudo a2ensite myflaskapp
sudo service apache2 restart

Now, if you navigate to your server’s IP address or domain name in a web browser, you should see your Flask application running.

Please replace mydomain.com, admin@mydomain.com, and /home/username/myflaskapp with your actual domain name, admin email, and the actual path to your Flask application respectively.

Also, ensure that the user under which Apache is running has the necessary permissions to access the directories and files of your Flask application.