django-asgi-lifespan 0.4.0

Django ASGI handler with Lifespan Protocol support.

Django ASGI Handler with Lifespan protocol support

• Documentation: https://illagrenan.github.io/django-asgi-lifespan
• PyPI: https://pypi.org/project/django-asgi-lifespan/
• License: MIT

Main features

async def example_view(request) -> HttpResponse:
    # The client is instanciated just once when the application starts,
    # and closed when the server shuts down
    httpx_client: httpx.AsyncClient = request.state["httpx_client"]

• The package includes a Django ASGIHandler subclass that handles the ASGI Lifespan Protocol without affecting HTTP request handling.
• Startup and Shutdown Lifespan events are converted to Django signals.
• The package allows for awaiting on signal receivers. This means you can set up things like an aiohttp ClientSession or an HTTPX AsyncClient when your app starts, and close them properly when your app ends. This concept is similar to events in FastAPI.

Quickstart

1. Python ^3.10 || ^3.11 || ^3.12 || ^3.13 and Django ^4.2 || ^5.0.3 || ^5.1 are supported. To install this package run:

   poetry add django-asgi-lifespan@latest
   

   or

   pip install --upgrade django-asgi-lifespan
   

2. Modify asgi.py to use a ASGI Lifespan compatible handler.

   from django_asgi_lifespan.asgi import get_asgi_application
   
   django_application = get_asgi_application()
   
   
   async def application(scope, receive, send):
       if scope["type"] in {"http", "lifespan"}:
           await django_application(scope, receive, send)
       else:
           raise NotImplementedError(
               f"Unknown scope type {scope['type']}"
           )
   

3. Add state middleware:

   MIDDLEWARE = [
       # ...
       "django_asgi_lifespan.middleware.LifespanStateMiddleware",
       # ...
   ]
   

4. Register async context manager:

   from contextlib import asynccontextmanager
   
   import httpx
   
   from django_asgi_lifespan.types import LifespanManager
   
   
   @asynccontextmanager
   async def httpx_lifespan_manager() -> LifespanManager:
       state = {
           "httpx_client": httpx.AsyncClient()
       }
   
       try:
           yield state
       finally:
           await state["httpx_client"].aclose()
   

   from django.apps import AppConfig
   
   from django_asgi_lifespan.register import register_lifespan_manager
   from .context import (
       httpx_lifespan_manager,
   )
   
   
   class ExampleAppConfig(AppConfig):
   
       def ready(self):
           register_lifespan_manager(
               context_manager=httpx_lifespan_manager
           )
   

5. Use some resource (in this case the HTTPX client) in views.

   from http import HTTPStatus
   
   import httpx
   from django.http import HttpResponse
   
   
   async def example_view(request) -> HttpResponse:
       httpx_client: httpx.AsyncClient = request.state["httpx_client"]
   
       await httpx_client.head("https://www.example.com/")
   
       return HttpResponse(
           "OK",
           status=HTTPStatus.OK,
           content_type="text/plain; charset=utf-8",
       )
   

6. Run uvicorn:

   uvicorn asgi:application --lifespan=on --port=8080