gracefully terminate server on sigint

server/alloc/main.py

@@ -3,6 +3,7 @@
 from websockets import serve
 import asyncio
 import os
+import signal
 
 import auth
 import stream
@@ -29,6 +30,10 @@ protocol = {
     'shutdown': shutdown_server
 }
 
+def kill_server(number, frame):
+    loop = asyncio.get_running_loop()
+    loop.run_in_executor( None, lambda: terminate['object'].set_result(True))
+signal.signal(signal.SIGINT, kill_server)
 
 async def main():
     wsServer = stream.SocketServer(protocol)