feat(ocpp-server): add graceful shutdown with signal handling

Handle SIGINT/SIGTERM for clean WebSocket close (code 1001) to all
connected charge points. Includes shutdown drain timeout, double-signal
force quit, and cross-platform Windows fallback via call_soon_threadsafe.

diff --git a/tests/ocpp-server/server.py b/tests/ocpp-server/server.py
index 63fba3e5d9c795d34587283b54e449c1e41a500d..b9772e9e4edbc084c6cea3782b1df84f69c942e8 100644 (file)
--- a/tests/ocpp-server/server.py
+++ b/tests/ocpp-server/server.py
@@ -4,6 +4,8 @@ import argparse
 import asyncio
 import logging
 import math
+import signal
+import sys
 from dataclasses import dataclass
 from datetime import datetime, timezone
 from enum import StrEnum
@@ -58,6 +60,7 @@ DEFAULT_PORT = 9000
 DEFAULT_HEARTBEAT_INTERVAL = 60
 DEFAULT_TOTAL_COST = 10.0
 MAX_REQUEST_ID = 2**31 - 1
+SHUTDOWN_TIMEOUT = 30.0
 SUBPROTOCOLS: list[websockets.Subprotocol] = [
     websockets.Subprotocol("ocpp2.0"),
     websockets.Subprotocol("ocpp2.0.1"),
@@ -769,7 +772,11 @@ async def main():
         auth_config.offline,
     )
 
-    server = await websockets.serve(
+    loop = asyncio.get_running_loop()
+    shutdown_count = 0
+    shutdown_event = asyncio.Event()
+
+    async with websockets.serve(
         partial(
             on_connect,
             config=config,
@@ -777,12 +784,55 @@ async def main():
         args.host,
         args.port,
         subprotocols=SUBPROTOCOLS,
-    )
-    logger.info("WebSocket Server Started on %s:%d", args.host, args.port)
+    ) as server:
+        logger.info("WebSocket Server Started on %s:%d", args.host, args.port)
+
+        def _on_signal(sig: signal.Signals) -> None:
+            nonlocal shutdown_count
+            shutdown_count += 1
+            if shutdown_count == 1:
+                logger.info("Received %s, initiating graceful shutdown...", sig.name)
+                server.close()
+                shutdown_event.set()
+            else:
+                logger.warning("Received %s again, forcing exit", sig.name)
+                sys.exit(128 + sig.value)
+
+        for sig in (signal.SIGINT, signal.SIGTERM):
+            try:
+                loop.add_signal_handler(sig, _on_signal, sig)
+            except NotImplementedError:
+                # Windows: ProactorEventLoop doesn't support add_signal_handler.
+                # signal.signal() fires outside the event loop, so schedule
+                # _on_signal into the loop via call_soon_threadsafe.
+                def _signal_handler(
+                    _signum: int,
+                    _frame: object,
+                    s: signal.Signals = sig,
+                ) -> None:
+                    loop.call_soon_threadsafe(_on_signal, s)
+
+                signal.signal(sig, _signal_handler)
+
+        await shutdown_event.wait()
+
+        try:
+            async with asyncio.timeout(SHUTDOWN_TIMEOUT):
+                await server.wait_closed()
+        except TimeoutError:
+            logger.warning(
+                "Shutdown timed out after %.0fs"
+                " — connections may not have closed cleanly",
+                SHUTDOWN_TIMEOUT,
+            )
 
-    await server.wait_closed()
+    logger.info("Server shutdown complete")
 
 
 if __name__ == "__main__":
     logging.basicConfig(level=logging.DEBUG)
-    asyncio.run(main())
+    try:
+        asyncio.run(main())
+    except KeyboardInterrupt:
+        pass
+    sys.exit(0)