add `KernelManager.client()`

IPython/kernel/manager.py

@@ -23,9 +23,10 b' import zmq'
 
 # Local imports
 from IPython.config.configurable import LoggingConfigurable
+from IPython.utils.importstring import import_item
 from IPython.utils.localinterfaces import LOCAL_IPS
 from IPython.utils.traitlets import (
-    Any, Instance, Unicode, List, Bool,
+    Any, Instance, Unicode, List, Bool, Type, DottedObjectName
 )
 from IPython.kernel import (
     make_ipkernel_cmd,
@@ -65,6 +66,12 b' class KernelManager(LoggingConfigurable, ConnectionFileMixin):'
     def _session_default(self):
         return Session(config=self.config)
 
+    # the class to create with our `client` method
+    client_class = DottedObjectName('IPython.kernel.client.KernelClient')
+    client_factory = Type()
+    def _client_class_changed(self, name, old, new):
+        self.client_factory = import_item(str(new))
+
     # The kernel process with which the KernelManager is communicating.
     # generally a Popen instance
     kernel = Any()
@@ -103,6 +110,23 b' class KernelManager(LoggingConfigurable, ConnectionFileMixin):'
         pass
 
     #--------------------------------------------------------------------------
+    # create a Client connected to our Kernel
+    #--------------------------------------------------------------------------
+
+    def client(self, **kwargs):
+        """Create a client configured to connect to our kernel"""
+        if self.client_factory is None:
+            self.client_factory = import_item(self.client_class)
+
+        kw = {}
+        kw.update(self.get_connection_info())
+        kw['connection_file'] = self.connection_file
+
+        # add kwargs last, for manual overrides
+        kw.update(kwargs)
+        return self.client_factory(**kw)
+
+    #--------------------------------------------------------------------------
     # Connection info
     #--------------------------------------------------------------------------
 
@@ -174,18 +198,19 b' class KernelManager(LoggingConfigurable, ConnectionFileMixin):'
         """
         return launch_kernel(kernel_cmd, **kw)
 
+    # Control socket used for polite kernel shutdown
+
     def _connect_control_socket(self):
         if self._control_socket is None:
             self._control_socket = self.connect_control()
+            self._control_socket.linger = 100
 
     def _close_control_socket(self):
         if self._control_socket is None:
             return
-        self._control_socket.linger = 100
         self._control_socket.close()
         self._control_socket = None
 
-
     def start_kernel(self, **kw):
         """Starts a kernel on this host in a separate process.
 

IPython/kernel/tests/test_message_spec.py

@@ -31,14 +31,14 b' from IPython.utils.traitlets import ('
 def setup():
     global KM, KC
     KM = KernelManager()
+    KM.client_factory = BlockingKernelClient
     KM.start_kernel(stdout=PIPE, stderr=PIPE)
-    KC = BlockingKernelClient(connection_file=KM.connection_file)
-    KC.load_connection_file()
+    KC = KM.client()
     KC.start_channels()
     
     # wait for kernel to be ready
-    KC.shell_channel.execute("pass")
-    KC.shell_channel.get_msg(block=True, timeout=5)
+    KC.execute("pass")
+    KC.get_shell_msg(block=True, timeout=5)
     flush_channels()