fix /hub/stats

everware/spawner.py

@@ -45,7 +45,6 @@ def __init__(self, **kwargs):
         ContainerHandler.__init__(self, **kwargs)
         EmailNotificator.__init__(self)
 
-
     # We override the executor here to increase the number of threads
     @property
     def executor(self):
@@ -55,6 +54,9 @@ def executor(self):
             cls._executor = ThreadPoolExecutor(20)
         return cls._executor
 
+    @staticmethod
+    def get_global_client():
+        return CustomDockerSpawner._client
 
     def _docker(self, method, *args, **kwargs):
         """wrapper for calling docker methods

everware/stats_handler.py

@@ -38,5 +38,8 @@ def get(self, *args, **kwargs):
     @gen.coroutine
     def get_running_container_count(self):
         """Get the number of currently running containers."""
-        return len(Client().containers(
-            filters={'status': self.container_statuses['running']}))
+        client = self.spawner_class.get_global_client()
+        if client is None:
+            # None means that there were no launches
+            return 0
+        return len(client.containers(filters={'status': self.container_statuses['running']}))