diff --git a/ansible/library/kolla_docker.py b/ansible/library/kolla_docker.py
index a4d57f838a..6f5a940cd6 100644
--- a/ansible/library/kolla_docker.py
+++ b/ansible/library/kolla_docker.py
@@ -675,6 +675,8 @@ class DockerWorker(object):
 
 
 def generate_module():
+    # NOTE(jeffrey4l): add empty string '' to choices let us use
+    # pid_mode: "{{ service.pid_mode | default ('') }}" in yaml
     argument_spec = dict(
         common_options=dict(required=False, type='dict', default=dict()),
         action=dict(required=True, type='str',
@@ -695,10 +697,10 @@ def generate_module():
         name=dict(required=False, type='str'),
         environment=dict(required=False, type='dict'),
         image=dict(required=False, type='str'),
-        ipc_mode=dict(required=False, type='str', choices=['host']),
+        ipc_mode=dict(required=False, type='str', choices=['host', '']),
         cap_add=dict(required=False, type='list', default=list()),
         security_opt=dict(required=False, type='list', default=list()),
-        pid_mode=dict(required=False, type='str', choices=['host']),
+        pid_mode=dict(required=False, type='str', choices=['host', '']),
         privileged=dict(required=False, type='bool', default=False),
         remove_on_exit=dict(required=False, type='bool', default=True),
         restart_policy=dict(required=False, type='str', choices=[
diff --git a/tests/test_kolla_docker.py b/tests/test_kolla_docker.py
index 69e302765d..bc5e910e68 100644
--- a/tests/test_kolla_docker.py
+++ b/tests/test_kolla_docker.py
@@ -60,10 +60,10 @@ class ModuleArgsTest(base.BaseTestCase):
             name=dict(required=False, type='str'),
             environment=dict(required=False, type='dict'),
             image=dict(required=False, type='str'),
-            ipc_mode=dict(required=False, type='str', choices=['host']),
+            ipc_mode=dict(required=False, type='str', choices=['host', '']),
             cap_add=dict(required=False, type='list', default=list()),
             security_opt=dict(required=False, type='list', default=list()),
-            pid_mode=dict(required=False, type='str', choices=['host']),
+            pid_mode=dict(required=False, type='str', choices=['host', '']),
             privileged=dict(required=False, type='bool', default=False),
             remove_on_exit=dict(required=False, type='bool', default=True),
             restart_policy=dict(