Python FastAPI Demo

A colorful FastAPI server with rich logging, background traffic generation, and comprehensive endpoint examples for testing HTTP methods and error scenarios.

Features

• Rich Console Logging: Colorized, formatted access logs with response times, status codes, and request IDs
• Background Traffic Generator: Simulates realistic traffic patterns to test your server
• HTTP Method Examples: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS
• Error Simulation: Built-in endpoints for testing 400, 404, 500, and 503 responses
• Request Correlation: X-Request-ID headers for request tracing
• Performance Metrics: Response time tracking with visual indicators (green/yellow/red)

Prerequisites

• Python 3.14 or higher
• uv - Modern Python package manager

Setup

1. Clone the Repository

git clone https://github.com/jaredthivener/python-demo.git
cd python-demo

2. Create a Virtual Environment and Install Dependencies

uv sync
source .venv/bin/activate  # On Windows: .venv\Scripts\activate

This command will create a virtual environment and install all dependencies from pyproject.toml. The .venv/bin/activate step activates the environment so you can use the installed packages.

Running the Server

Activate the virtual environment first (if not already activated):

source .venv/bin/activate  # On Windows: .venv\Scripts\activate

Then start the development server with auto-reload:

uvicorn main:app --reload --no-access-log

The server will be available at http://127.0.0.1:8000

API Documentation:

• Swagger UI: http://127.0.0.1:8000/docs - Interactive API explorer
• ReDoc: http://127.0.0.1:8000/redoc - Alternative API documentation

Server Features

• Auto-reload: The server automatically restarts when you modify main.py
• Background Traffic: Once running, the server generates simulated traffic to itself
• Rich Logging: All requests are logged with color-coded formatting

API Endpoints

Basic Endpoints

• GET / - Returns a simple hello message
• GET /api/tags - Returns a list of tags
• GET /api/ps - Health check endpoint

Data Operations

• POST /api/pull - Simulates a pull operation
• PUT /api/items/{id} - Updates an item
• PATCH /api/items/{id} - Partially updates an item
• DELETE /api/items/{id} - Deletes an item

HTTP Method Tests

• HEAD /api/status - Returns headers only
• OPTIONS /api/options - Returns allowed methods

Error Simulation Endpoints

• GET /api/error/400 - Returns 400 Bad Request
• GET /api/error/404 - Returns 404 Not Found
• GET /api/error/500 - Returns 500 Internal Server Error
• GET /api/error/503 - Returns 503 Service Unavailable

Example Usage

# Test GET endpoint
curl http://127.0.0.1:8000/api/tags

# Test POST endpoint
curl -X POST http://127.0.0.1:8000/api/pull

# Test error endpoint
curl http://127.0.0.1:8000/api/error/404

Development

Project Structure

python-demo/
├── main.py              # Main application file
├── requirements.txt     # Python dependencies
├── README.md           # This file
└── .venv/              # Virtual environment (ignored by git)

Configuration

Key settings in main.py:

• WARN_MS: Response time threshold for yellow warning (default: 100ms)
• SLOW_MS: Response time threshold for red slow indicator (default: 500ms)
• SERVER_PORT: Port for background traffic generation (default: 8000)

Logging

The application uses Rich for beautiful console logging. Each request line includes:

• Timestamp
• Status code (color-coded: green 2xx, cyan 3xx, yellow 4xx, red 5xx)
• Response time in milliseconds
• Response size
• Client IP
• HTTP method (color-coded by method type)
• Request path
• Request ID for correlation

Stopping the Server

Press CTRL+C to stop the development server.

Dependencies

• fastapi: Modern web framework for building APIs
• uvicorn: ASGI server for running FastAPI
• httpx: Async HTTP client for background traffic generation
• rich: Beautiful terminal rendering and logging

License

MIT

Support

For issues or questions, please open an issue on the GitHub repository.