Fix static file handling on localhost

Note: this does not apply to production because we serve static files from Nginx there: those static file requests never make it to the Django application and, indeed, it is not configured to serve static files. This change uses the ASGI static file handler that the Django `runserver` management command uses and correctly handles streaming responses. The only consequence of not doing this is that warnings will appear locally and, if for some reason local interactions are bypassing the static file cache on the browser, you could get a memory leak. Again, that only applies to local environments. Python code never interacts with, considers, or is configured for static files in production, so this is not an issue for production. The correct behaviour for production, which you can test by setting ENVIRONMENT to something other than `local` in `api/.env`, is to 404 on static files.

api/conf/asgi.py

@@ -1,6 +1,8 @@
 import os
 
 import django
+from django.conf import settings
+from django.contrib.staticfiles.handlers import ASGIStaticFilesHandler
 
 from conf.asgi_handler import OpenverseASGIHandler
 
@@ -14,3 +16,7 @@ def get_asgi_application():
 
 
 application = get_asgi_application()
+
+
+if settings.ENVIRONMENT == "local":
+    static_files_application = ASGIStaticFilesHandler(application)

api/conf/urls/__init__.py

@@ -43,6 +43,3 @@
         ),
     ),
 ]
-
-if settings.ENVIRONMENT == "local":
-    urlpatterns += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)

api/run.py

@@ -4,12 +4,16 @@
 
 
 if __name__ == "__main__":
+    is_local = os.getenv("ENVIRONMENT") == "local"
+
+    app = "conf.asgi:static_files_application" if is_local else "conf.asgi:application"
+
     uvicorn.run(
-        "conf.asgi:application",
+        app,
         host="0.0.0.0",
         port=8000,
         workers=1,
-        reload=os.getenv("ENVIRONMENT") == "local",
+        reload=is_local,
         log_level="debug",
         log_config={
             "version": 1,