FlaskAppDeployment

First runthrough based on: https://www.rosehosting.com/blog/how-to-install-flask-on-ubuntu-22-04-with-apache-and-wsgi/

Install Apache

sudo systemctl status apache2

Already installed - skipping this section.

Install Python / PIP

$ python --version
$ pip --version

Already installed, skipping this section.

Create Python Virtual Enviroment (Venv) for Flask

$ cd /opt/cryptopunk
$ mkdir -p flask/reddit-oauth2/
$ cd flask/reddit-oauth2/
$ python3 -m venv flask-venv

Install Flask

$ cd /opt/cryptopunk/flask/reddit-oauth2
$ source flask-venv/bin/activate

After sourcing the venv activate script, your pip and python ops will occur within the virtual environment, without wrecking up the system-wide Python environment.

Shell prompt should look like:

(flask-venv) user@host:/opt/cryptopunk/flask/reddit-oauth2$

$ pip install flask

Test Install

/opt/cryptopunk/flask/reddit-oauth2/app.py

from flask import Flask
app = Flask(__name__)

@app.route('/')
def index():
    return 'Hello World'

CLI

$ export FLASK_APP=app.py
$ flask run --host=0.0.0.0

Then hit it with a browser: http://localhost:5000/

Control-C to quit the app, then

$ deactivate

to exit the venv.

Configure Apache

Install WSGI

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

Create WSGI File

$ cd /opt/cryptopunk/flask/reddit-oauth2/
$ emacs -nw flask-app.wsgi

/opt/cryptopunk/flask/reddit-oauth2/flask-app.wsgi

import sys
sys.path.insert(0,'/opt/cryptopunk/flask/reddit-oauth2')

from app import app as application

Apache Virtual Host

/etc/hosts

127.0.0.1 localhost foobar.com

/etc/apache2/sites-available/100-cryptopunk-reddit-oauth2.conf

<VirtualHost *:80>
ServerName foobar.com
DocumentRoot /opt/cryptopunk/flask/reddit-oauth2/

WSGIDaemonProcess app user=www-data group=www-data threads=5 python-home=/opt/cryptopunk/flask/reddit-oauth2/flask-venv
WSGIScriptAlias / /opt/cryptopunk/flask/reddit-oauth2/flask-app.wsgi

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

<Directory /opt/cryptopunk/flask/reddit-oauth2>
WSGIProcessGroup app
WSGIApplicationGroup %{GLOBAL}
Order deny,allow
Require all granted
</Directory>
</VirtualHost>

$ sudo a2ensite 100-cryptopunk-reddit-oauth2.conf
$ apachectl -t
$ sudo systemctl restart apache2

Deploy Hello World

$ ssh -i deadclone admin@www.iterativechaos.com

/etc/apache2/sites-enabled/100-default-le-ssl.conf

    WSGIScriptAlias /prompt /var/www/prompt_api/flaskapp.wsgi
    <Directory /var/www/prompt_api/FlaskApp/>
      Order allow,deny
      Allow from all
    </Directory>