Fix AttributeError in `get_config`

Change-Id: I52bdc44800da6c1393a69c4faf96375235ef98bb
Closes-Bug: #1627690

os_client_config/__init__.py

@@ -26,7 +26,7 @@ __version__ = pbr.version.VersionInfo('os_client_config').version_string()
 def get_config(service_key=None, options=None, **kwargs):
     config = OpenStackConfig()
     if options:
-        config.register_argparse_options(options, sys.argv, service_key)
+        config.register_argparse_arguments(options, sys.argv, service_key)
         parsed_options = options.parse_known_args(sys.argv)
     else:
         parsed_options = None

os_client_config/config.py

@@ -641,7 +641,7 @@ class OpenStackConfig(object):
         # completely broken
         return cloud
 
-    def register_argparse_arguments(self, parser, argv, service_keys=[]):
+    def register_argparse_arguments(self, parser, argv, service_keys=None):
         """Register all of the common argparse options needed.
 
         Given an argparse parser, register the keystoneauth Session arguments,
@@ -660,6 +660,9 @@ class OpenStackConfig(object):
                                                     is requested
         """
 
+        if service_keys is None:
+            service_keys = []
+
         # Fix argv in place - mapping any keys with embedded _ in them to -
         _fix_argv(argv)
 

os_client_config/tests/test_init.py

@@ -0,0 +1,33 @@
+#  Licensed under the Apache License, Version 2.0 (the "License"); you may
+#  not use this file except in compliance with the License. You may obtain
+#  a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#  License for the specific language governing permissions and limitations
+#  under the License.
+
+import argparse
+
+import os_client_config
+from os_client_config.tests import base
+
+
+class TestInit(base.TestCase):
+    def test_get_config_without_arg_parser(self):
+        cloud_config = os_client_config.get_config(options=None)
+        self.assertIsInstance(
+            cloud_config,
+            os_client_config.cloud_config.CloudConfig
+        )
+
+    def test_get_config_with_arg_parser(self):
+        cloud_config = os_client_config.get_config(
+            options=argparse.ArgumentParser())
+        self.assertIsInstance(
+            cloud_config,
+            os_client_config.cloud_config.CloudConfig
+        )