Linglong Web

Linglong Web is a FastAPI toolkit for microservice scenarios, focusing on "simple startup, flexible extension, and complete observability".

中文文档：see README.zh-CN.md

Links

• GitHub: https://github.com/10000ms/linglong_web
• Issues: https://github.com/10000ms/linglong_web/issues
• Changelog: https://github.com/10000ms/linglong_web/blob/master/CHANGELOG.md

Why this library

When building microservices with FastAPI, you often need:

• Service lifecycle management - startup, shutdown, health checks, graceful termination
• Resource orchestration - database connections, cache, message queues, schedulers
• Observability - request-id propagation, structured logging, rate limiting
• Extensibility - plugin hooks for service registration, remote config, etc.

Linglong Web provides all these out of the box as modular components.

Features

• AppServer lifecycle - Built-in middleware, error handling, health checks, and signal handling
• Extension hooks - on_config_ready, on_app_created, on_startup, on_shutdown for custom logic injection
• Thread-safe config - LinglongConfig with hot reload support
• Resource management - Unified initialization for PostgreSQL, Redis, MongoDB, RabbitMQ, Celery
• HTTP client - aiohttp wrapper with request-id propagation and unified error handling
• Decorators - Redis cache, rate limit, and distributed lock decorators
• Scheduler - aioclock integration for periodic tasks
• Bilingual comments - Chinese and English comments throughout the codebase

Installation

# Core: FastAPI bootstrapper + HTTP client + scheduler + Redis-backed decorators
pip install linglong-web

# Add resource backends on demand
pip install "linglong-web[postgres]"   # PostgreSQL (asyncpg + SQLAlchemy)
pip install "linglong-web[mongo]"      # MongoDB (PyMongo async)
pip install "linglong-web[rabbitmq]"   # RabbitMQ (aio-pika)
pip install "linglong-web[celery]"     # Celery
pip install "linglong-web[all]"        # everything

import linglong_web always works with just the core install; a backend you haven't installed only raises a clear error if you actually initialize it.

Quick Start

import asyncio

from linglong_web import LinglongConfigBase, init_config
from linglong_web import build_success_response
from linglong_web import BaseRoute, ServerRouter
from linglong_web import LinglongAppServer


class DevConfig(LinglongConfigBase):
    """Development configuration"""
    DEBUG = True
    SERVICE_NAME = "demo-service"


router = ServerRouter()
router.initialize([
    BaseRoute(
        path="/ping",
        method="GET",
        handler=lambda: build_success_response({"pong": True}),
    )
])

init_config({"dev": DevConfig}, mode_name="dev")


async def main():
    app_server = LinglongAppServer()
    await app_server.initialize(
        service_name="demo-service",
        router=router.get_router(),
        config_dict={"dev": DevConfig},
    )
    await app_server.start(host="0.0.0.0", port=8080)


if __name__ == "__main__":
    asyncio.run(main())

Module Overview

Extension Example

from linglong_web.server_extensions import BaseServerExtension


class RegistryExtension(BaseServerExtension):
    """Example: custom service registration logic"""

    def __init__(self, client):
        self._client = client

    async def on_startup(self, server):
        payload = {"service": server.service_name, "instance": server.instance_id}
        await self._client.register(payload)
        server.register_shutdown_callback(lambda: self._client.deregister(payload))


extensions = [RegistryExtension(client)]
await app_server.initialize(
    service_name="demo",
    router=router.get_router(),
    config_dict={"dev": DevConfig},
    extensions=extensions,
)

Linglong no longer bundles service registration or remote config capabilities. Implement them in your business repository using extension hooks.

Testing & Coverage

# Run tests with coverage
pytest tests/ -v --cov=linglong_web --cov-report=term-missing

# Or with PYTHONPATH
PYTHONPATH=. pytest tests/ -v --cov=linglong_web --cov-report=term-missing

• All new modules should maintain 80%+ test coverage.
• Use pytest-asyncio and pytest-mock for fine-grained mocking of resources, rate limiters, and signal handlers.

Project Layout

linglong_web/
├── linglong_web/
│   ├── core/               # Core modules
│   │   ├── server.py       # FastAPI bootstrapper
│   │   ├── config.py       # Config proxy
│   │   ├── resource.py     # Resource manager
│   │   ├── http.py         # HTTP client
│   │   ├── cacher.py       # Cache decorator
│   │   ├── limiter.py      # Rate limit decorator
│   │   └── ...
│   └── utils/              # Utilities
├── tests/                  # Test suite
└── docs/                   # Documentation

Versioning

The package version is sourced from linglong_web/__version__.py.

License

MIT License. See LICENSE.