🐳 Scalable Docker API (Flask + NGINX + Compose)

This is a simple horizontally-scalable API demo using Docker Compose, Flask, and NGINX.

Each API container responds with its own hostname, so you can see which container handled each request — perfect for understanding how container scaling and load balancing works locally.

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📁 Project Structure

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├── app.py              # Flask API returning hostname
├── Dockerfile          # Containerizes the app
├── nginx.conf          # Load balances across API containers
└── docker-compose.yml  # Defines and scales services

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🚀 Quick Start

1. Clone or create this project

   git clone https://github.com/your-username/scalable-api.git
   cd scalable-api

2. Start it up and scale

   docker compose up --build --scale api=3 -d

3. Visit your API Open your browser at: http://localhost:8080
   Refresh a few times — each response should show a different container hostname.

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🧠 How It Works

• The Flask api service runs in multiple containers.
• NGINX receives all incoming traffic and forwards it to a randomly selected container.
• Docker Compose handles building, scaling, and networking between services.

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⚙️ Commands

Scale up/down the number of containers:

docker compose up --scale api=5 -d

Stop and remove everything:

docker compose down

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🚧 Possible Next Steps

• Add automatic CPU-based scaling
• Add monitoring with Prometheus + Grafana
• Deploy on Kubernetes for production-ready orchestration

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Made with 🧠 & 🐳 by RobinsonLaw