Add timeout for web_channel in trial_runner (#2710)

tools/nni_trial_tool/web_channel.py

@@ -2,7 +2,7 @@
 # Licensed under the MIT license.
 
 import asyncio
-
+import os
 import websockets
 
 from .base_channel import BaseChannel
@@ -16,6 +16,7 @@ class WebChannel(BaseChannel):
         self.args = args
         self.client = None
         self.in_cache = b""
+        self.timeout = 10
 
         super(WebChannel, self).__init__(args)
 
@@ -23,12 +24,15 @@ class WebChannel(BaseChannel):
 
     def _inner_open(self):
         url = "ws://{}:{}".format(self.args.nnimanager_ip, self.args.nnimanager_port)
-        nni_log(LogType.Info, 'WebChannel: connected with info %s' % url)
-
-        connect = websockets.connect(url)
+        try:
+            connect = asyncio.wait_for(websockets.connect(url), self.timeout)
             self._event_loop = asyncio.get_event_loop()
             client = self._event_loop.run_until_complete(connect)
             self.client = client
+            nni_log(LogType.Info, 'WebChannel: connected with info %s' % url)
+        except asyncio.TimeoutError:
+            nni_log(LogType.Error, 'connect to %s timeout! Please make sure NNIManagerIP configured correctly, and accessable.' % url)
+            os._exit(1)
 
     def _inner_close(self):
         if self.client is not None: