Fix/server error handling (#212)

* chore: add venv/ to gitignore

* fix: add server error handling and graceful shutdown

* Fix linting issues in server.py

.gitignore

@@ -11,6 +11,7 @@ static/browser_history/*.gif
 
 # Virtual environments
 .venv
+venv/
 
 # Environment variables
 .env

server.py

@@ -7,7 +7,8 @@ Server script for running the DeerFlow API.
 
 import argparse
 import logging
-
+import signal
+import sys
 import uvicorn
 
 # Configure logging
@@ -18,6 +19,17 @@ logging.basicConfig(
 
 logger = logging.getLogger(__name__)
 
+
+def handle_shutdown(signum, frame):
+    """Handle graceful shutdown on SIGTERM/SIGINT"""
+    logger.info("Received shutdown signal. Starting graceful shutdown...")
+    sys.exit(0)
+
+
+# Register signal handlers
+signal.signal(signal.SIGTERM, handle_shutdown)
+signal.signal(signal.SIGINT, handle_shutdown)
+
 if __name__ == "__main__":
     # Parse command line arguments
     parser = argparse.ArgumentParser(description="Run the DeerFlow API server")
@@ -50,12 +62,11 @@ if __name__ == "__main__":
 
     # Determine reload setting
     reload = False
-
-    # Command line arguments override defaults
     if args.reload:
         reload = True
 
-    logger.info("Starting DeerFlow API server")
+    try:
+        logger.info(f"Starting DeerFlow API server on {args.host}:{args.port}")
         uvicorn.run(
             "src.server:app",
             host=args.host,
@@ -63,3 +74,6 @@ if __name__ == "__main__":
             reload=reload,
             log_level=args.log_level,
         )
+    except Exception as e:
+        logger.error(f"Failed to start server: {str(e)}")
+        sys.exit(1)