fix: Fix server startup issue with PipelineNotInitializedError

- Add allow_create parameter to get_namespace_data() to permit internal initialization
- initialize_pipeline_status() now uses allow_create=True to create the namespace
- External calls still get the error if pipeline_status is not initialized
- This maintains the improved error messages while allowing proper server startup

Fixes server startup failure reported in PR #1978

lightrag/kg/shared_storage.py

@@ -1059,7 +1059,7 @@ async def initialize_pipeline_status():
     Initialize pipeline namespace with default values.
     This function is called during FASTAPI lifespan for each worker.
     """
-    pipeline_namespace = await get_namespace_data("pipeline_status")
+    pipeline_namespace = await get_namespace_data("pipeline_status", allow_create=True)
 
     async with get_internal_lock():
         # Check if already initialized by checking for required fields
@@ -1194,8 +1194,14 @@ async def try_initialize_namespace(namespace: str) -> bool:
     return False
 
 
-async def get_namespace_data(namespace: str) -> Dict[str, Any]:
+async def get_namespace_data(namespace: str, allow_create: bool = False) -> Dict[str, Any]:
-    """get the shared data reference for specific namespace"""
+    """get the shared data reference for specific namespace
+    
+    Args:
+        namespace: The namespace to retrieve
+        allow_create: If True, allows creation of the namespace if it doesn't exist.
+                     Used internally by initialize_pipeline_status().
+    """
     if _shared_dicts is None:
         direct_log(
             f"Error: try to getnanmespace before it is initialized, pid={os.getpid()}",
@@ -1206,12 +1212,12 @@ async def get_namespace_data(namespace: str) -> Dict[str, Any]:
     async with get_internal_lock():
         if namespace not in _shared_dicts:
             # Special handling for pipeline_status namespace
-            if namespace == "pipeline_status":
+            if namespace == "pipeline_status" and not allow_create:
                 # Check if pipeline_status should have been initialized but wasn't
                 # This helps users understand they need to call initialize_pipeline_status()
                 raise PipelineNotInitializedError(namespace)
             
-            # For other namespaces, create them dynamically as before
+            # For other namespaces or when allow_create=True, create them dynamically
             if _is_multiprocess and _manager is not None:
                 _shared_dicts[namespace] = _manager.dict()
             else: