Flask VPS Hosting – Deploy Flask Apps on High-Performance Servers

How to Deploy Flask on Ubuntu 24.04 – Production-Ready Setup

Deploying Flask in a production environment requires more than just running python app.py. This guide shows you how to install Flask, configure a Flask production server, and serve your app reliably with Gunicorn and Nginx on Ubuntu 24.04.

Assumptions

• You have a Ubuntu 24.04 VPS
• SSH access with root or sudo privileges
• Domain name pointed to your VPS (A record → VPS IP)
• Goal: deploy Flask in a stable, production-ready environment

Step 1 – Connect to Your VPS via SSH

Open a terminal and run:

ssh root@your-vps-ip

If using a private key:

ssh -i /path/to/private-key.pem root@your-vps-ip

Once logged in, switch to root if needed:

sudo -i

You’re now operating as root and can run system-level commands.

Step 2 – Update System Packages

sudo apt update
sudo apt upgrade -y

Keeping your system updated ensures a stable Flask production server.

Step 3 – Install Dependencies and Flask

Install Python, pip, virtual environment support, and Nginx:

sudo apt install python3 python3-pip python3-venv nginx ufw -y

Create a dedicated user for Flask:

sudo useradd -m -s /bin/bash flaskuser
sudo mkdir /home/flaskuser/flaskapp
sudo chown flaskuser:flaskuser /home/flaskuser/flaskapp

Switch to the new user:

su - flaskuser
cd /home/flaskuser/flaskapp
python3 -m venv venv
source venv/bin/activate
pip install --upgrade pip
pip install flask gunicorn

Now you have installed Flask and Gunicorn for production.

Step 4 – Create Your Flask Application

Create app.py:

from flask import Flask
app = Flask(__name__)

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

Create wsgi.py:

from app import app

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

This sets up the WSGI entry point for your Flask production server.

Step 5 – Configure Gunicorn for Production

Create systemd service /etc/systemd/system/flaskapp.service:

[Unit]
Description=Gunicorn instance to serve Flask app
After=network.target

[Service]
User=flaskuser
Group=www-data
WorkingDirectory=/home/flaskuser/flaskapp
Environment="PATH=/home/flaskuser/flaskapp/venv/bin"
ExecStart=/home/flaskuser/flaskapp/venv/bin/gunicorn --workers 4 --bind unix:/home/flaskuser/flaskapp/flaskapp.sock -m 007 wsgi:app

[Install]
WantedBy=multi-user.target

Enable and start the service:

sudo systemctl daemon-reload
sudo systemctl enable flaskapp
sudo systemctl start flaskapp
sudo systemctl status flaskapp

Step 6 – Configure Nginx as Reverse Proxy

Create /etc/nginx/sites-available/flaskapp:

server {
    listen 80;
    server_name your_domain.com www.your_domain.com;

    location / {
        include proxy_params;
        proxy_pass http://unix:/home/flaskuser/flaskapp/flaskapp.sock;
    }
}

Enable site and restart Nginx:

sudo ln -s /etc/nginx/sites-available/flaskapp /etc/nginx/sites-enabled
sudo nginx -t
sudo systemctl restart nginx
sudo ufw allow 'Nginx Full'

Your Flask production server is now live.

Production Optimizations

1. Workers Count – Start with 3–4 Gunicorn workers. Adjust based on RAM and traffic.
2. Background Jobs – Use Celery or RQ in separate services to avoid blocking Gunicorn.
3. HTTPS – Use Certbot to secure your Flask production server.
4. Logging – Separate Gunicorn and Nginx logs for monitoring.
5. Firewall & Security – Allow only HTTP, HTTPS, and SSH. Use fail2ban if needed.
6. Scaling – Move to dedicated servers or increase workers for high traffic.

By following this workflow, you can perform a Flask setup, deploy Flask applications, and run a stable Flask production server on Ubuntu 24.04. This setup ensures your app is ready for real-world traffic.