Day 23 of #90DaysOfCloud: Deploying a Python App on AWS EC2

Today’s milestone was all about deploying a Python Flask web application on a live AWS EC2 instance using native tools — no Docker, no containers. This gives a deep dive into what happens under the hood when preparing apps for production.

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🧠 Why This Matters

Flask is one of the most widely used micro-frameworks for Python web development. Hosting it manually teaches essential DevOps skills:

• Linux server administration

• Python package management

• Reverse proxy configuration with NGINX

• Running apps in the background

• Production-grade practices with Gunicorn

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☁️ Infrastructure Overview

✅ Services & Tools Used:

• AWS EC2 instance (Amazon Linux 2)

• Python 3 and pip

• Flask web framework

• Gunicorn (WSGI production server)

• NGINX (as a reverse proxy)

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🚀 Step-by-Step Deployment

🔹 1. Launch EC2 Instance

• AMI: Amazon Linux 2

• Instance type: t2.micro (Free tier)

• Security Group Rules:

  • SSH (Port 22): Your IP

  • HTTP (Port 80): Anywhere

Assign a public IP and SSH into it:

ssh -i "your-key.pem" ec2-user@<your-ec2-public-ip>

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🔹 2. Install Python and pip

Amazon Linux 2 comes with Python 3 pre-installed. Confirm it:

python3 --version

If not installed:

sudo yum install python3 -y

Install pip:

sudo yum install python3-pip -y

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🔹 3. Create Flask Application

Create a new directory and Flask app:

mkdir flaskapp && cd flaskapp
vim app.py

Paste the following simple Flask code:

from flask import Flask
app = Flask(__name__)

@app.route('/')
def home():
    return "Hello from Flask on AWS EC2!"

if __name__ == '__main__':
    app.run(host='0.0.0.0')

Install Flask:

pip3 install flask

Test the app locally:

python3 app.py

Go to http://<your-ec2-public-ip>:5000 to see the app.

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🔹 4. Use Gunicorn for Production

Gunicorn allows serving Flask apps more reliably in production:

pip3 install gunicorn

Run app with Gunicorn:

gunicorn -w 3 -b 0.0.0.0:5000 app:app

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🔹 5. Install and Configure NGINX

Install NGINX:

sudo amazon-linux-extras enable nginx1
sudo yum install nginx -y
sudo systemctl start nginx
sudo systemctl enable nginx

Edit the default config:

sudo vim /etc/nginx/nginx.conf

Add this inside the server {} block:

location / {
    proxy_pass http://127.0.0.1:5000;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

Restart NGINX:

sudo systemctl restart nginx

Now visit http://<your-ec2-public-ip> and your Flask app will load!

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🔹 6. Run Flask in the Background

Use pm2 to keep app running:

sudo npm install -g pm2
pm2 start gunicorn --name flaskapp -- gunicorn -w 3 -b 0.0.0.0:5000 app:app

Optional: save process for reboot

pm2 startup
pm2 save

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✅ Summary of Key Commands

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🔐 Best Practices

• Always use Gunicorn or similar WSGI server in production

• NGINX helps handle static files and acts as a reverse proxy

• Use pm2 or systemd to manage processes

• Restrict inbound rules for safety

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📅 What’s Next?

Tomorrow is Day 24 → I’ll dive into AWS EBS & AMI fundamentals, including:

• Mounting and formatting EBS volumes

• Creating and managing custom AMIs

• Taking EBS snapshots

• Copying snapshots across regions for backup and recovery

This will strengthen my understanding of data durability, backup strategies, and image-based deployments in real-world cloud setups!

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Stay tuned and follow the journey! 💻☁️

#Flask #Python #AWS #EC2 #NGINX #Gunicorn #DevOps #Cloud #90DaysOfCloud