Multi-Tier Flask Web Application on AWS

A full-stack, cloud-deployed web application built with a proper 3-tier architecture — frontend, backend, and database — all running on AWS.

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The Problem

Most beginners deploy apps locally and call it done. Real cloud engineering means separating concerns — your frontend, backend, and database should be independent, scalable, and properly secured. This project replicates that pattern on AWS.

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Architecture

 User Browser
      │
      ▼
 AWS EC2 (Ubuntu)
 └── Flask App (port 5000)
      ├── Jinja2 HTML Templates (Frontend)
      ├── Flask Routes (Backend Logic)
      └── PyMySQL ──────────────────▶ Amazon RDS (MySQL)
                                          └── sneha_db.users table

3 Tiers:

Tier	Technology	Where
Frontend	HTML + Jinja2 Templates	EC2
Backend	Python + Flask	EC2
Database	MySQL via PyMySQL	Amazon RDS

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Tech Stack

Tool	Purpose
Python & Flask	Backend web framework
Jinja2	Server-side HTML templating
Amazon EC2 (Ubuntu)	App server in the cloud
Amazon RDS (MySQL)	Managed relational database
PyMySQL	Python → MySQL connector
AWS Security Groups	Network access control

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Features

• Submit a user form (name + email) via a web page
• Flask backend processes and validates the input
• Data is stored in an Amazon RDS MySQL database
• View all submitted users at /users
• Successfully deployed and tested on AWS EC2 — EC2 instance stopped after testing to avoid Free Tier charges

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📸 Screenshots

Web Form (running on EC2)

Users Stored in RDS Database

AWS EC2 Instance (Running)

Amazon RDS Database (Available)

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How to Run It Yourself

Prerequisites

• AWS account (Free Tier works)
• EC2 instance (Ubuntu 22.04)
• Amazon RDS MySQL instance

Step 1 — Set Up RDS (MySQL)

Create a MySQL DB instance in Amazon RDS, then run:

CREATE DATABASE sneha_db;
USE sneha_db;
CREATE TABLE users (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(100),
  email VARCHAR(100)
);

Step 2 — Set Up EC2

ssh -i your-key.pem ubuntu@your-ec2-public-ip
sudo apt update && sudo apt install -y python3 python3-pip git
pip3 install flask pymysql

Step 3 — Configure the App

Edit config.py with your RDS credentials:

DB_HOST = 'your-rds-endpoint'
DB_USER = 'your-username'
DB_PASSWORD = 'your-password'
DB_NAME = 'sneha_db'

Never push real credentials to GitHub. Use environment variables or AWS Secrets Manager in production.

Step 4 — Run the App

git clone https://github.com/sneha020902/multi-tier-flask-aws-app.git
cd multi-tier-flask-aws-app
python3 app.py

Step 5 — Access the App

Open your browser at http://your-ec2-public-ip:5000 Make sure port 5000 is open in your EC2 Security Group.

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What I Learned

• How to design and deploy a proper 3-tier architecture on AWS
• Configuring and connecting to Amazon RDS from an EC2 instance
• Using PyMySQL to run queries from Python
• Managing AWS Security Groups to allow specific port traffic
• Debugging real cloud issues: DB connection timeouts, port conflicts, IAM permissions
• Why never to hardcode credentials and how to use config files safely

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Future Improvements

• Dockerize the Flask app for consistent deployments
• Replace raw SQL with SQLAlchemy ORM
• Add form validation and error handling
• Set up HTTPS with AWS ACM + Load Balancer
• Use AWS Secrets Manager for credential management
• Add a CI/CD pipeline with GitHub Actions

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Author

Sneha Agrawal — Aspiring Cloud & DevOps Engineer 🔗 LinkedIn · GitHub · Portfolio