Added support for cgroup parent

Clean up cgroup_parent usage

docker/utils/utils.py

@@ -395,7 +395,7 @@ def create_host_config(
     restart_policy=None, cap_add=None, cap_drop=None, devices=None,
     extra_hosts=None, read_only=None, pid_mode=None, ipc_mode=None,
     security_opt=None, ulimits=None, log_config=None, mem_limit=None,
-    memswap_limit=None
+    memswap_limit=None, cgroup_parent=None
 ):
     host_config = {}
 
@@ -500,6 +500,9 @@ def create_host_config(
     if lxc_conf is not None:
         host_config['LxcConf'] = lxc_conf
 
+    if cgroup_parent is not None:
+        host_config['CgroupParent'] = cgroup_parent
+
     if ulimits is not None:
         if not isinstance(ulimits, list):
             raise errors.DockerException(

tests/test.py

@@ -492,6 +492,24 @@ class DockerClientTest(Cleanup, base.BaseTestCase):
         self.assertEqual(args[1]['headers'],
                          {'Content-Type': 'application/json'})
 
+    def test_create_container_with_cgroup_parent(self):
+        try:
+            self.client.create_container(
+                'busybox', 'ls', host_config=create_host_config(
+                    cgroup_parent='test'
+                )
+            )
+        except Exception as e:
+            self.fail('Command should not raise exception: {0}'.format(e))
+
+        args = fake_request.call_args
+        self.assertEqual(args[0][0],
+                         url_prefix + 'containers/create')
+        data = json.loads(args[1]['data'])
+        self.assertIn('HostConfig', data)
+        self.assertIn('CgroupParent', data['HostConfig'])
+        self.assertEqual(data['HostConfig']['CgroupParent'], 'test')
+
     def test_create_container_with_working_dir(self):
         try:
             self.client.create_container('busybox', 'ls',