Use clearer middleware pattern and consistent app export name

api/api/utils/aiohttp.py

@@ -4,7 +4,7 @@
 
 import aiohttp
 
-from conf.asgi import application
+from conf.asgi import APPLICATION_LIFECYCLE
 
 
 logger = logging.getLogger(__name__)
@@ -56,7 +56,7 @@ async def get_aiohttp_session() -> aiohttp.ClientSession:
 
         if create_session:
             session = aiohttp.ClientSession()
-            application.register_shutdown_handler(session.close)
+            APPLICATION_LIFECYCLE.register_shutdown_handler(session.close)
             _SESSIONS[loop] = session
 
         return _SESSIONS[loop]

api/conf/asgi.py

@@ -1,25 +1,20 @@
 import os
 
-import django
 from django.conf import settings
 from django.contrib.staticfiles.handlers import ASGIStaticFilesHandler
+from django.core.asgi import get_asgi_application
 
-from conf.asgi_handler import OpenverseASGIHandler
+from conf.lifecycle_handler import ASGILifecycleHandler
 
 
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "conf.settings")
 
 
-def get_asgi_application():
-    django.setup(set_prefix=False)
-    return OpenverseASGIHandler()
-
-
-application = get_asgi_application()
+application = APPLICATION_LIFECYCLE = ASGILifecycleHandler(get_asgi_application())
 
 
 if settings.ENVIRONMENT == "local":
-    static_files_application = ASGIStaticFilesHandler(application)
+    application = ASGIStaticFilesHandler(application)
 
 
 if settings.GC_DEBUG_LOGGING:

api/conf/asgi_handler.py → api/conf/lifecycle_handler.py

@@ -6,28 +6,34 @@
 
 from django.core.handlers.asgi import ASGIHandler
 
+import sentry_sdk
+
 
 parent_logger = logging.getLogger(__name__)
 
 
-class OpenverseASGIHandler(ASGIHandler):
+class ASGILifecycleHandler:
     """
-    Extend default ASGIHandler to implement lifetime hooks.
+    Handle ASGI lifecycle messages.
+
+    Django's ASGIHandler does not handle these messages,
+    so we have to implement it ourselves. Only shutdown handlers
+    are currently supported.
 
-    Handlers are registered by calling `register_shutdown_handler`.
-    The class maintains only weak references to handler functions
+    Register shutdown handlers using the `register_shutdown_handler`
+    method. The class maintains only weak references to handler functions
     and methods to prevent memory leaks. This removes the need
     for explicit deregistration of handlers if, for example, their associated
-    objects (if a method) or contexts are garbage collected.
+    contexts are garbage collected.
 
     Asynchronous handlers are automatically supported via `async_to_sync`
     and do not need special consideration at registration time.
     """
 
-    logger = parent_logger.getChild("OpenverseASGIHandler")
+    logger = parent_logger.getChild("ASGILifecycleHandler")
 
-    def __init__(self):
-        super().__init__()
+    def __init__(self, app: ASGIHandler):
+        self.app = app
         self._on_shutdown: list[weakref.WeakMethod | weakref.ref] = []
         self.has_shutdown = False
 
@@ -59,7 +65,7 @@ async def __call__(self, scope, receive, send):
                     await send({"type": "lifespan.shutdown.complete"})
                     return
 
-        await super().__call__(scope, receive, send)
+        await self.app(scope, receive, send)
 
     async def shutdown(self):
         live_handlers = 0
@@ -72,10 +78,14 @@ async def shutdown(self):
 
             live_handlers += 1
 
-            if asyncio.iscoroutinefunction(handler):
-                await handler()
-            else:
-                handler()
+            try:
+                if asyncio.iscoroutinefunction(handler):
+                    await handler()
+                else:
+                    handler()
+            except Exception as exc:
+                sentry_sdk.capture_exception(exc)
+                self.logger.error(f"Handler {repr(handler)} raised exception.")
 
         self.logger.info(f"Executed {live_handlers} handler(s) before shutdown.")
         self.has_shutdown = True

api/run.py

@@ -6,10 +6,8 @@
 if __name__ == "__main__":
     is_local = os.getenv("ENVIRONMENT") == "local"
 
-    app = "conf.asgi:static_files_application" if is_local else "conf.asgi:application"
-
     uvicorn.run(
-        app,
+        "conf.asgi:application",
         host="0.0.0.0",
         port=8000,
         workers=1,

api/test/conftest.py

@@ -1,7 +1,7 @@
 import pytest
 from asgiref.sync import async_to_sync
 
-from conf.asgi import application
+from conf.asgi import APPLICATION_LIFECYCLE
 
 
 @pytest.fixture(scope="session", autouse=True)
@@ -16,4 +16,4 @@ def call_application_shutdown():
     fine here, so it's not a problem.
     """
     yield
-    async_to_sync(application.shutdown)()
+    async_to_sync(APPLICATION_LIFECYCLE.shutdown)()

api/test/unit/utils/test_aiohttp.py

@@ -4,7 +4,7 @@
 from asgiref.sync import async_to_sync
 
 from api.utils.aiohttp import get_aiohttp_session
-from conf.asgi import application
+from conf.asgi import APPLICATION_LIFECYCLE
 
 
 @pytest.fixture(autouse=True)
@@ -18,7 +18,7 @@ def _get_new_loop():
 
     yield _get_new_loop
 
-    async_to_sync(application.shutdown)()
+    async_to_sync(APPLICATION_LIFECYCLE.shutdown)()
     for loop in loops:
         loop.close()
 
@@ -56,9 +56,9 @@ def test_multiple_loops_reuse_separate_sessions(get_new_loop):
 
 
 def test_registers_shutdown_cleanup(get_new_loop):
-    assert len(application._on_shutdown) == 0
+    assert len(APPLICATION_LIFECYCLE._on_shutdown) == 0
 
     loop = get_new_loop()
     loop.run_until_complete(get_aiohttp_session())
 
-    assert len(application._on_shutdown) == 1
+    assert len(APPLICATION_LIFECYCLE._on_shutdown) == 1