log2fast-fastapi

🚀 Advanced logging module for FastAPI with file rotation, colored output, and environment-based auto-configuration

📖 Conventions reference: this package follows the 2fast-handbook for ecosystem conventions (structure, versioning, README, commits, release).

[!WARNING] Internal Use Notice

This package is designed and maintained by the Solautyc Team for internal use. While it is publicly available, it may not work as expected in all environments or use cases outside of our specific infrastructure. We do not provide support or guarantees for external usage, and we are not responsible for any issues that may arise from using this package in other contexts.

Use at your own risk. Contributions and feedback are welcome, but compatibility with external environments is not guaranteed.

Features

• 🎨 Multiple Output Formats: JSON (production), Colored (development), Structured (debugging), Simple (testing)
• 🌍 Environment-Based Configuration: Automatic setup for dev, test, prod, and debug
• 📦 Module-Based Loggers: Each module gets its own logger instance
• 🔄 File Rotation: Automatic log file rotation with configurable size
• 🔄 Environment-Specific Logging: Control which logs appear in which environments (prevent sensitive data leaks)
• 🚀 FastAPI Integration: Middleware for automatic request/response logging with unique request IDs
• 📊 Structured Logging: Add context data to any log message
• 📊 Context Injection: Support for request_id, user_id, and custom context data
• 🎯 Zero Configuration: Works out of the box with sensible defaults

📚 Documentation

• Usage Guide - Comprehensive usage guide with examples
• File Management - Complete guide on log rotation and storage (English)
• Gestión de Archivos - Guía completa de rotación y almacenamiento (Español)
• Logger Best Practices - Best practices for creating and naming loggers

Installation

From PyPI (Recommended)

pip install log2fast-fastapi

From Source

# Clone the repository
git clone https://github.com/AngelDanielSanchezCastillo/log2fast-fastapi.git
cd log2fast-fastapi

# Install in development mode
pip install -e .

# Or install with dev dependencies
pip install -e ".[dev]"

Quick Start

Basic Usage

from log2fast_fastapi import get_logger

logger = get_logger(__name__)

logger.info("Application started")
logger.warning("This is a warning")
logger.error("An error occurred")

FastAPI Integration

from fastapi import FastAPI
from log2fast_fastapi import RequestLoggingMiddleware, get_logger

app = FastAPI()
app.add_middleware(RequestLoggingMiddleware)

logger = get_logger(__name__)

@app.get("/")
async def root():
    logger.info("Root endpoint accessed")
    return {"message": "Hello World"}

Logging with Context

from log2fast_fastapi import get_logger

logger = get_logger(__name__)

logger.info(
    "User logged in",
    extra_data={
        "user_id": "12345",
        "ip_address": "192.168.1.1"
    }
)

Environment-Specific Logging (Prevent Sensitive Data Leaks!)

# Logs ONLY in development/debug (NOT in production)
logger.debug(
    "Sensitive debug info",
    extra_data={"password_hash": "...", "token": "..."},
    only_in=["development", "debug"]
)

# Logs ONLY in production
logger.info(
    "Performance metrics",
    extra_data={"response_time": 120},
    only_in=["production"]
)

Configuration

Simple: Just set the environment in .env

# That's it! Format and level auto-configure
LOG_ENVIRONMENT=production

Auto-configuration by environment:

Environment	Auto Level	Auto Format
development	INFO	colored
production	WARNING	json
testing	INFO	simple
debug	DEBUG	colored

Optional: Override defaults

# Optional: Override auto-configuration
LOG_LEVEL=DEBUG
LOG_FORMAT=json
LOG_FILE_SETTINGS__ENABLED=true

Environment Presets

Development

• Format: Colored console output
• Level: INFO
• Perfect for local development

Production

• Format: JSON (structured)
• Level: WARNING
• Optimized for log aggregation tools

Testing

• Format: Simple
• Level: INFO
• Minimal output for tests

Debug

• Format: Colored
• Level: DEBUG
• Maximum verbosity

Documentation

See docs/usage.md for complete documentation including:

• Advanced configuration
• Custom formatters
• Best practices
• Integration examples

Example

Run the example application:

python log2fast_fastapi/example.py

Then visit:

• http://localhost:8000/ - Root endpoint
• http://localhost:8000/users/123 - User endpoint
• http://localhost:8000/docs - API documentation

Testing

Run the test suite:

python log2fast_fastapi/tests/test_logging.py

Module Structure

log2fast-fastapi/
├── pyproject.toml       # Package configuration
├── MANIFEST.in          # Additional files to include
├── README.md            # This file
├── LICENSE              # License file
├── src/
│   └── log2fast_fastapi/
│       ├── __init__.py          # Main exports
│       ├── __version__.py       # Version information
│       ├── base.py              # Core FastLogger class
│       ├── settings.py          # Configuration with Pydantic
│       ├── formatters.py        # Custom log formatters
│       └── middleware.py        # FastAPI middleware
├── docs/
│   ├── usage.md                 # Complete documentation
│   ├── file_management.md       # File rotation guide (EN)
│   ├── file_management_es.md    # File rotation guide (ES)
│   ├── logger_best_practices.md # Best practices
│   └── publishing.md            # PyPI publishing guide
├── examples/
│   ├── example.py               # Basic example
│   ├── demo_features.py         # Feature demonstrations
│   └── demo_rotation.py         # Rotation examples
└── tests/
    ├── test_logging.py          # Test suite
    └── test_new_features.py     # Feature tests

Acknowledgments

This project uses the following open-source packages:

• FastAPI - Modern, fast web framework for building APIs (MIT License)
• Pydantic - Data validation using Python type annotations (MIT License)
• Pydantic Settings - Settings management using Pydantic (MIT License)

We are grateful to the maintainers and contributors of these projects for their excellent work.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Copyright (c) 2026 Angel Daniel Sanchez Castillo

Note: This package is designed and maintained by the Solautyc Team for internal use. While publicly available under MIT license, use at your own risk.