feat(websockets): run the WS server as a django management command.

This allows to handle the loading of the settings in a consistant way,
and aditionnaly to provide a way to override the `WEBSOCKET_BACK_HOST`
and `WEBSOCKET_BACK_PORT` settings with arg commands `--host` and
`--port`.

Without this change, because of how we are currently loading our
settings, we would require the settings the be exposed by the
`umap.settings.__init__` file.

Previous implementations were exposing these settings, with the
following code:

```python
settings_as_dict = {k: v for k, v in globals().items() if k.isupper()}
  ```

docs/config/settings.md

@@ -279,12 +279,15 @@ Setting `WEBSOCKET_ENABLED` to `True` will **not** enable real-time
 collaboration on all the maps served by the server. Instead, a switch will be
 available in the "advanced properties" of the map.
 
-The websocket server can be run with the following command:
+The websocket server can be started with the following command:
 
 ```bash
-python -m umap.ws
+umap run_websocket_server
 ```
 
+And can take optional settings `--host` and `--port` (default values are defined in
+the settings).
+
 Configuration example:
 
 ```python

umap/management/commands/run_websocket_server.py

@@ -0,0 +1,23 @@
+from django.conf import settings
+from django.core.management.base import BaseCommand
+
+from umap import ws
+
+
+class Command(BaseCommand):
+    help = "Run the websocket server"
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--host",
+            help="The server host to bind to.",
+            default=settings.WEBSOCKET_BACK_HOST,
+        )
+        parser.add_argument(
+            "--port",
+            help="The server port to bind to.",
+            default=settings.WEBSOCKET_BACK_PORT,
+        )
+
+    def handle(self, *args, **options):
+        ws.run(options["host"], options["port"])

umap/settings/__init__.py

@@ -43,6 +43,3 @@ if path:
                     globals()["STATICFILES_DIRS"].insert(0, value)
                 else:
                     globals()[key] = value
-
-# Expose these settings for consumption by e.g. django.settings.configure.
-settings_as_dict = {k: v for k, v in globals().items() if k.isupper()}

umap/ws.py

@@ -4,7 +4,6 @@ import asyncio
 from collections import defaultdict
 from typing import Literal, Optional
 
-import django
 import websockets
 from django.conf import settings
 from django.core.signing import TimestampSigner
@@ -12,13 +11,6 @@ from pydantic import BaseModel, ValidationError
 from websockets import WebSocketClientProtocol
 from websockets.server import serve
 
-# This needs to run before the django-specific imports
-# See https://docs.djangoproject.com/en/5.0/topics/settings/#calling-django-setup-is-required-for-standalone-django-usage
-from umap.settings import settings_as_dict
-
-settings.configure(**settings_as_dict)
-django.setup()
-
 from umap.models import Map, User  # NOQA
 
 # Contains the list of websocket connections handled by this process.
@@ -81,7 +73,7 @@ async def handler(websocket):
         await join_and_listen(map_id, permissions, user, websocket)
 
 
-async def main():
+def run(host, port):
     if not settings.WEBSOCKET_ENABLED:
         msg = (
             "WEBSOCKET_ENABLED should be set to True to run the WebSocket Server. "
@@ -92,12 +84,9 @@ async def main():
         print(msg)
         exit(1)
 
-    host = settings.WEBSOCKET_BACK_HOST
-    port = settings.WEBSOCKET_BACK_PORT
+    async def _serve():
+        async with serve(handler, host, port):
+            print(f"Waiting for connections on {host}:{port}")
+            await asyncio.Future()  # run forever
 
-    async with serve(handler, host, port):
-        print(f"Waiting for connections on {host}:{port}")
-        await asyncio.Future()  # run forever
-
-
-asyncio.run(main())
+    asyncio.run(_serve())