How I run and host my Flask servers on Ubuntu

First you'll need some dependencies:

pip install supervisor virtualenv

Next you need to make a directory for your application:

cd ~
git clone [email protected]:Username/flask-app flask-app
cd flask-app

# Setup Virtualenv
virtualenv .flaskapp

Assume flask-app hierarchy is like so:

flask-app/
  app/
    __init__.py
    resources/
    controllers/
    models/
    views/
  app.py

app.py should have:

from app import app

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

Next you will want to make your source the virtualenv:

source .flaskapp/bin/activate

Make sure you have a requirements.txt file in your project

pip install -r requirements.txt

# Install uwsgi for serving the app
pip install uwsgi

Next we need to make a supervisor config file, below is an example config file:

[program:flask-app]
directory=/home/user/flask-app
command=/home/user/flask-app/.flaskapp/bin/uwsgi --http :9230 --file ./app.py --callable app
autostart=true
autorestart=true
stderr_logfile=/home/user/flask-app/flask-app.err.log
stdout_logfile=/home/user/flask-app/flask-app.out.log

Save this at /etc/supervisor/conf.d/flask-app.conf

Lets go through this config line by line:

[program:flask-app]: Registers this app as flask-app with supervisor. Allows for commands like supervisorctl restart flask-app

directory=/home/user/flask-app: Home directory of app

command=/home/user/flask...: This will run the uwsgi command with the port 9320 and file being the app.py file in our flask-app project. --callable is for the application folder of the app. If it's not called flask-app/app then rename it to whatever folder is inside flask-app

The rest is just for supervisor and debug logs. They are selfexplainatory.

Now we need to setup an nginx config file:

Run:

sudo nano /etc/nginx/conf.d/virtual.conf

Add:

server {
  listen 80;
  
  server_name sub.domain.com;
  
  location / {
    proxy_pass http://127.0.0.1:9230
  }
}

Next run nginx -t to confirm config file is okay.

Then run

supervisorctl reread
systemctl restart supervisor
systemctl restart nginx

Now try to go to your domain set in server_name you should see your flask app running! If you get a 500 or something check the ~/flask-app/flask-app.*.log files.

M4cs/Flask Server Setup Unix.md