Container.exec_run returns a namedtuple w/ attrs exit_code & output

Signed-off-by: Frank Sachsenheim <funkyfuture@riseup.net>

docker/models/containers.py

@@ -3,7 +3,7 @@ import copy
 from ..api import APIClient
 from ..errors import (ContainerError, ImageNotFound,
                       create_unexpected_kwargs_error)
-from ..types import HostConfig
+from ..types import ExecResult, HostConfig
 from ..utils import version_gte
 from .images import Image
 from .resource import Collection, Model
@@ -150,7 +150,7 @@ class Container(Model):
             workdir (str): Path to working directory for this exec session
 
         Returns:
-            (tuple): A tuple of (exit_code, output)
+            (ExecResult): A tuple of (exit_code, output)
                 exit_code: (int):
                     Exit code for the executed command or ``None`` if
                     either ``stream```or ``socket`` is ``True``.
@@ -172,10 +172,11 @@ class Container(Model):
             resp['Id'], detach=detach, tty=tty, stream=stream, socket=socket
         )
         if socket or stream:
-            return None, exec_output
+            return ExecResult(None, exec_output)
         else:
-            return (self.client.api.exec_inspect(resp['Id'])['ExitCode'],
-                    exec_output)
+            return ExecResult(
+                self.client.api.exec_inspect(resp['Id'])['ExitCode'],
+                exec_output)
 
     def export(self):
         """

docker/types/__init__.py

 # flake8: noqa
-from .containers import ContainerConfig, HostConfig, LogConfig, Ulimit
+from .containers import (ContainerConfig, ExecResult, HostConfig, LogConfig,
+                         Ulimit)
 from .healthcheck import Healthcheck
 from .networks import EndpointConfig, IPAMConfig, IPAMPool, NetworkingConfig
 from .services import (

docker/types/containers.py

+from collections import namedtuple
 import six
 import warnings
 
@@ -11,6 +12,11 @@ from .base import DictType
 from .healthcheck import Healthcheck
 
 
+ExecResult = namedtuple('ExecResult', 'exit_code,output')
+""" A result of Container.exec_run with the properties ``exit_code`` and
+    ``output``. """
+
+
 class LogConfigTypesEnum(object):
     _values = (
         'json-file',