Allow custom PID mode for the container

Docker added support for sharing PID namespaces with other containers
since version 1.12 (see https://github.com/docker/docker/pull/22481).

Signed-off-by: Stepan Stipl <stepan@stipl.net>

docker/utils/utils.py

@@ -735,9 +735,7 @@ def create_host_config(binds=None, port_bindings=None, lxc_conf=None,
 
         host_config['ShmSize'] = shm_size
 
-    if pid_mode not in (None, 'host'):
-        raise host_config_value_error('pid_mode', pid_mode)
-    elif pid_mode:
+    if pid_mode:
         host_config['PidMode'] = pid_mode
 
     if ipc_mode:

tests/integration/api_container_test.py

@@ -365,9 +365,6 @@ class CreateContainerTest(BaseAPIIntegrationTest):
         self.assertRaises(TypeError,
                           self.client.create_host_config, mem_swappiness='40')
 
-        self.assertRaises(ValueError,
-                          self.client.create_host_config, pid_mode='40')
-
     def test_create_with_environment_variable_no_value(self):
         container = self.client.create_container(
             BUSYBOX,