feat: Improve graceful shutdown handling and enhance application initialization logging

jira-webhook-llm.py

@@ -11,7 +11,7 @@ import sys
 from typing import Optional
 from datetime import datetime
 import asyncio
-from functools import wraps
+from functools import wraps, partial
 
 from config import settings
 from webhooks.handlers import JiraWebhookHandler
@@ -23,40 +23,104 @@ configure_logging(log_level="DEBUG")
 
 import signal
 
-try:
+from contextlib import asynccontextmanager
-    app = FastAPI()
-    logger.info("FastAPI application initialized")
 
-    @app.on_event("shutdown")
+
-    async def shutdown_event():
+
-        """Handle application shutdown"""
+# Setup async-compatible signal handling
+def handle_shutdown_signal(signum, loop):
+    """Graceful shutdown signal handler"""
+    logger.info(f"Received signal {signum}, initiating shutdown...")
+    # Set shutdown flag and remove signal handlers to prevent reentrancy
+    if not hasattr(loop, '_shutdown'):
+        loop._shutdown = True
+
+        # Prevent further signal handling
+        for sig in (signal.SIGTERM, signal.SIGINT):
+            loop.remove_signal_handler(sig)
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """Handle startup and shutdown events"""
+    # Startup
+    try:
+        logger.info("Initializing application...")
+        
+        # Initialize event loop
+        loop = asyncio.get_running_loop()
+        logger.debug("Event loop initialized")
+        
+        # Setup signal handlers
+        for sig in (signal.SIGTERM, signal.SIGINT):
+            loop.add_signal_handler(sig, partial(handle_shutdown_signal, sig, loop))
+        logger.info("Signal handlers configured successfully")
+        
+        # Verify critical components
+        if not hasattr(settings, 'langfuse_handler'):
+            logger.error("Langfuse handler not found in settings")
+            raise RuntimeError("Langfuse handler not initialized")
+            
+        logger.info("Application initialized successfully")
+        yield
+        
+        # Check shutdown flag before cleanup
+        loop = asyncio.get_running_loop()
+        if hasattr(loop, '_shutdown'):
+            logger.info("Shutdown initiated, starting cleanup...")
+    except Exception as e:
+        logger.critical(f"Application initialization failed: {str(e)}")
+        raise
+    finally:
+        # Shutdown
         logger.info("Shutting down application...")
         try:
-            # Cleanup Langfuse client if exists
+            # Cleanup sequence with async safety
+            cleanup_tasks = []
+            shutdown_success = True
+            
+            # Close langfuse with retry
             if hasattr(settings, 'langfuse_handler') and hasattr(settings.langfuse_handler, 'close'):
+                async def close_langfuse():
+                    try:
+                        await asyncio.wait_for(settings.langfuse_handler.close(), timeout=5.0)
+                        logger.info("Langfuse client closed successfully")
+                    except asyncio.TimeoutError:
+                        logger.warning("Timeout while closing Langfuse client")
+                    except Exception as e:
+                        logger.error(f"Error closing Langfuse client: {str(e)}")
+                cleanup_tasks.append(close_langfuse())
+            
+            # Remove confirm_shutdown entirely
+            # Execute all cleanup tasks with timeout
+            try:
+                await asyncio.wait_for(asyncio.gather(*cleanup_tasks), timeout=10.0)
+            except asyncio.TimeoutError:
+                logger.warning("Timeout during cleanup sequence")
+            loop.stop()  # Explicit loop stop after cleanup
+            # Cancel all pending tasks
+            async def cancel_pending_tasks():
                 try:
-                    await settings.langfuse_handler.close()
+                    pending = [t for t in asyncio.all_tasks() if t is not asyncio.current_task()]
+                    for task in pending:
+                        task.cancel()
+                    await asyncio.gather(*pending, return_exceptions=True)
+                    logger.info("Pending tasks cancelled successfully")
                 except Exception as e:
-                    logger.warning(f"Error closing handler: {str(e)}")
+                    logger.error(f"Error cancelling pending tasks: {str(e)}")
-            logger.info("Cleanup completed successfully")
+            cleanup_tasks.append(cancel_pending_tasks())
+            
+            # Execute all cleanup tasks with timeout
+            try:
+                await asyncio.wait_for(asyncio.gather(*cleanup_tasks), timeout=10.0)
+            except asyncio.TimeoutError:
+                logger.warning("Timeout during cleanup sequence")
+            loop.stop()  # Add explicit loop stop after cleanup
+            
         except Exception as e:
             logger.error(f"Error during shutdown: {str(e)}")
             raise
 
-    def handle_shutdown_signal(signum, frame):
+# Initialize FastAPI app after lifespan definition
-        """Handle OS signals for graceful shutdown"""
+app = FastAPI(lifespan=lifespan)
-        logger.info(f"Received signal {signum}, initiating shutdown...")
-        # Exit immediately after cleanup is complete
-        os._exit(0)
-
-    # Register signal handlers
-    signal.signal(signal.SIGTERM, handle_shutdown_signal)
-    signal.signal(signal.SIGINT, handle_shutdown_signal)
-
-except Exception as e:
-    logger.critical(f"Failed to initialize FastAPI: {str(e)}")
-    logger.warning("Application cannot continue without FastAPI initialization")
-    sys.exit(1)
 
 def retry(max_retries: int = 3, delay: float = 1.0):
     """Decorator for retrying failed operations"""
@@ -138,7 +202,3 @@ async def test_llm():
         updated="2025-07-04T21:40:00Z"
     )
     return await webhook_handler.handle_webhook(test_payload)
-
-# if __name__ == "__main__":
-#     import uvicorn
-#     uvicorn.run(app, host="0.0.0.0", port=8000)

requirements.txt

@@ -1,6 +1,6 @@
 fastapi==0.111.0
-pydantic==2.9.0 # Changed from 2.7.4 to meet ollama's requirement
+pydantic>=2.9.0
-pydantic-settings==2.0.0
+pydantic-settings>=2.0.0
 langchain==0.3.26
 langchain-ollama==0.3.3
 langchain-openai==0.3.27
@@ -16,4 +16,4 @@ pytest==8.2.0
 pytest-asyncio==0.23.5
 pytest-cov==4.1.0
 httpx==0.27.0
-PyYAML
+PyYAML>=6.0.2