fix(join): increase join_world timeout, log dedicated server stdout/stderr, null check multiplayer

backend/app/services/game_servers.py

@@ -50,6 +50,7 @@ class _WorldServer:
     proc: subprocess.Popen
     status_path: Path
     token: str
+    log_path: Path | None = None
     started_at: float = field(default_factory=time.time)
     last_join: float = field(default_factory=time.time)
 
@@ -150,6 +151,7 @@ class GameServerSupervisor:
         token = secrets.token_urlsafe(32)
         status_path = self._runtime_dir / f"world_{world_id}_{port}.json"
         status_path.unlink(missing_ok=True)
+        log_path = self._runtime_dir / f"world_{world_id}_{port}.log"
         cmd = [
             settings.GODOT_BIN, "--headless",
             "--path", settings.GAME_PROJECT_DIR,
@@ -160,9 +162,10 @@ class GameServerSupervisor:
             "--api-url", settings.GAME_SERVER_INTERNAL_API_URL,
             "--server-token", token,
         ]
-        proc = subprocess.Popen(cmd, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+        log_file = open(log_path, "w")
+        proc = subprocess.Popen(cmd, stdout=log_file, stderr=subprocess.STDOUT)
         return _WorldServer(
-            world_id=world_id, port=port, proc=proc, status_path=status_path, token=token
+            world_id=world_id, port=port, proc=proc, status_path=status_path, token=token, log_path=log_path
         )
 
     def _free_port(self) -> int:
@@ -199,13 +202,27 @@ class GameServerSupervisor:
             if srv.is_ready():
                 return
             if not srv.alive():
+                log_snippet = ""
+                if srv.log_path and srv.log_path.exists():
+                    try:
+                        log_snippet = srv.log_path.read_text()[-500:]
+                    except OSError:
+                        pass
                 raise TimeoutError(
                     f"server process for world {srv.world_id} exited before becoming ready"
+                    + (f": {log_snippet}" if log_snippet else "")
                 )
             await asyncio.sleep(0.25)
+        log_snippet = ""
+        if srv.log_path and srv.log_path.exists():
+            try:
+                log_snippet = srv.log_path.read_text()[-500:]
+            except OSError:
+                pass
         raise TimeoutError(
             f"server for world {srv.world_id} did not report ready within "
             f"{settings.GAME_SERVER_READY_TIMEOUT_SECONDS}s"
+            + (f": {log_snippet}" if log_snippet else "")
         )
 
     async def _reap_loop(self) -> None: