Fix problem of RBAC command arguments

Add default value '*' to argument 'target_tenant'

Change-Id: I61c35ee4def53bc141a9ce562c01fe7422663a0e
Closes-Bug: #1596750

neutronclient/neutron/v2_0/rbac.py

@@ -69,6 +69,7 @@ class CreateRBACPolicy(neutronV20.CreateCommand):
             help=_('Type of the object that RBAC policy affects.'))
         parser.add_argument(
             '--target-tenant',
+            default='*',
             help=_('ID of the tenant to which the RBAC '
                    'policy will be enforced.'))
         parser.add_argument(

neutronclient/tests/unit/test_cli20_rbac.py

@@ -44,7 +44,7 @@ class CLITestV20RBACBaseJSON(test_cli20.CLITestV20Base):
                 '--action', 'access_as_shared']
         position_names = ['object_id', 'object_type',
                           'target_tenant', 'action']
-        position_values = [name, self.object_type_val, None,
+        position_values = [name, self.object_type_val, '*',
                            'access_as_shared']
         self._test_create_resource(resource, cmd, name, myid, args,
                                    position_names, position_values)

releasenotes/notes/fix-rbac-create-command-dd40a474f0f092db.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - Fix 'bug 1596750 <https://bugs.launchpad.net/neutron/+bug/1596750>'
+    that using 'rbac-create' without specifying 'target-tenant' will
+    return 'Request Failed internal server error while processing your
+    request'.
+    Update the default value of the argument '--target-tenant' to '*'