Deploying Flask Applications on AWS EC2

Deploying a Flask application properly is crucial for ensuring your web application runs efficiently and securely in a production environment. This guide will walk you through the process of deploying a Flask application on AWS EC2 using Gunicorn as the WSGI server and Nginx as the reverse proxy.

Prerequisites

• An AWS account
• Basic knowledge of command line and SSH
• A Flask application ready for deployment
• Understanding of Python virtual environments

1. Launch an EC2 Instance

First, we'll need to set up our EC2 instance:

• Sign in to AWS Management Console & Navigate to EC2 Dashboard
• Click "Launch Instance" & Choose Ubuntu Server 20.04 LTS (or newer)
• Select t2.micro (free tier eligible)
• Configure security group to allow HTTP (80), HTTPS (443), and SSH (22)

2. Connect to Your Instance

ssh -i /path/to/your-key.pem ubuntu@your-public-ip

3. Install Required Packages

sudo apt update
sudo apt upgrade -y
sudo apt install python3 python3-pip python3-venv nginx git -y

4. Set Up Your Application

Clone your application repository and set up a virtual environment:

git clone https://github.com/yourusername/your-repo.git
cd your-repo
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
pip install gunicorn

5. Configure Gunicorn

Create a systemd service file: `sudo nano /etc/systemd/system/myflaskapp.service`

[Unit]
Description=Gunicorn instance for myflaskapp
After=network.target

[Service]
User=ubuntu
Group=www-data
WorkingDirectory=/home/ubuntu/your-repo
Environment="PATH=/home/ubuntu/your-repo/.venv/bin"
ExecStart=/home/ubuntu/your-repo/.venv/bin/gunicorn --workers 3 --bind unix:myflaskapp.sock -m 007 app:app

[Install]
WantedBy=multi-user.target

6. Configure Nginx

Create configuration: `sudo nano /etc/nginx/sites-available/myflaskapp`

server {
  listen 80;
  server_name your-public-ip;

  location / {
    proxy_pass http://unix:/home/ubuntu/your-repo/myflaskapp.sock;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
  }
}

7. Conclusion

Your Flask application is now running on EC2 with Gunicorn and Nginx! Don't forget to set up HTTPS next.