Implement DiscordGateway503Filter for logging

src/fablabot/main.py

@@ -31,6 +31,31 @@
 with open(DISCORD_TOKEN_FILE) as f:
     DISCORD_TOKEN = f.read().strip()
 
+class DiscordGateway503Filter(logging.Filter):
+    """Filter Discord gateway 503 warnings into a cleaner message."""
+
+    def filter(self, record: logging.LogRecord) -> bool:
+        if not record.exc_info:
+            return True
+
+        exception = record.exc_info[1]
+
+        from aiohttp import WSServerHandshakeError
+
+        if (
+            isinstance(exception, WSServerHandshakeError)
+            and getattr(exception, "status", None) == 503
+        ):
+            retry_message = record.getMessage()
+
+            logger.warning(
+                "Discord Gateway indisponible (503). %s",
+                retry_message,
+            )
+
+            return False
+
+        return True
 
 class Fablabot(commands.Bot):
     """Discord bot implementation for the DeVinci Fablab server."""
@@ -99,6 +124,9 @@ async def on_command_error(self, ctx: commands.Context[Any], exception: Exceptio
 
 def main() -> None:
     """Run the bot using the token from the environment."""
+    discord_logger = logging.getLogger("discord.client")
+    discord_logger.addFilter(DiscordGateway503Filter())
+
     logger.info("Starting FablaBot.")
     bot = Fablabot()
     logger.info("Running bot.")