Flask Containerization Demo
This project showcases the fundamentals of containerization using a simple Python Flask web application. It’s a lightweight example built to demonstrate how a basic web service can be packaged, deployed, and executed consistently across different environments using Docker.
📦 What Is Containerization?
Containerization is the technique of packaging an application along with its dependencies, configurations, and runtime into a single executable unit called a container. Unlike virtual machines, containers share the host system’s kernel, making them much faster and more efficient.
In short: “It works on my machine” now truly means “it works everywhere.”
Docker is the tool that makes this possible. It allows you to:
Package and distribute applications seamlessly
Run the same image on any system with Docker installed
Simplify updates, scaling, and deployment pipelines
🚀 Project Overview
This repository includes:
A simple Flask app (app.py) that returns a friendly greeting
A requirements.txt file listing dependencies
A Dockerfile with image build instructions
This README providing an overview and usage guide
Once containerized, the Flask app can run anywhere — on local machines, servers, or cloud platforms — without worrying about environment setup.
🧱 Folder Structure flask-container-demo/ │ ├── app.py ├── requirements.txt ├── Dockerfile └── README.md
🐳 Building and Running the Container
Build the Docker image
docker build -t flask-container-demo .
Run the container
docker run -p 5000:5000 flask-container-demo
Access the app
Open your browser and go to http://localhost:5000
Expected output:
Hello from a Docker container!
⚙️ How It Works
The Dockerfile specifies how the image is constructed:
Starts from a minimal Python base image (python:3.11-slim)
Installs Flask and dependencies
Copies the application code into the container
Exposes port 5000 and runs the app
docker build creates a self-contained image.
docker run launches a new container instance, isolated yet lightweight.
🧩 Why It’s Useful
Containerization provides major advantages for developers and teams:
Eliminates dependency and environment conflicts
Ensures consistent behavior across systems
Speeds up deployment and scaling
Enables smoother transitions between development, staging, and production
This small Flask app serves as a clear, minimal example of how Docker streamlines software delivery and environment management.
🪴 Optional Improvements
You can extend this demo by:
Adding a docker-compose.yml for multi-service setups (e.g., Flask + Database)
Publishing your image to Docker Hub
Automating builds with GitHub Actions
Trying containerization with another framework or language
License: MIT Author: Keshava A K
Purpose: Educational project to demonstrate Docker-based containerization in action