Support /credits API

Currently, Distil supports getting credits of current user. This
patch adds the support for Distil client and test cases are added
together.

Change-Id: Ibbfd4858d205f78de7a3cda8748b130151a1e266

distilclient/tests/unit/v2/test_credits.py

@@ -0,0 +1,43 @@
+# Copyright (c) 2017 Catalyst IT Ltd.
+#
+# 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 mock
+import uuid
+
+import distilclient
+from distilclient import base
+from distilclient.tests.unit import utils
+from distilclient.v2 import client
+
+
+class InvoicesTest(utils.TestCase):
+
+    def setUp(self):
+        super(InvoicesTest, self).setUp()
+        self.client = client.Client(session=client.session.Session(),
+                                    api_version=distilclient.API_MAX_VERSION,
+                                    distil_url=uuid.uuid4().hex, retries=3,
+                                    input_auth_token='token')
+
+    @mock.patch.object(base.Manager, '_list')
+    def test_list_with_project_id(self, mock_list):
+        self.client.credits.list('project_id')
+        mock_list.assert_called_with('/v2/credits?project_id=project_id',
+                                     'credits')
+
+    @mock.patch.object(base.Manager, '_list')
+    def test_list_without_project_id(self, mock_list):
+        self.client.credits.list()
+        mock_list.assert_called_with('/v2/credits', 'credits')

distilclient/v2/client.py

@@ -20,6 +20,7 @@ import six
 
 from distilclient.common import httpclient
 from distilclient import exceptions
+from distilclient.v2 import credits
 from distilclient.v2 import invoices
 from distilclient.v2 import measurements
 from distilclient.v2 import quotations
@@ -190,6 +191,7 @@ class Client(object):
         self.measurements = measurements.MeasurementManager(self)
         self.invoices = invoices.InvoiceManager(self)
         self.quotations = quotations.QuotationManager(self)
+        self.credits = credits.CreditManager(self)
 
         self._load_extensions(extensions)
 

distilclient/v2/credits.py

@@ -0,0 +1,32 @@
+# Copyright 2017 Catalyst IT Ltd.
+#
+#    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.
+
+from distilclient import base
+
+
+class CreditManager(base.Manager):
+
+    def list(self, project_id=None):
+        """Retrieve a list of credits.
+
+        :param project_id: Project ID, there there is no project id given,
+                           Distil will use the project ID from token.
+        :returns: A list of credits.
+        """
+
+        url = "/v2/credits"
+        if project_id:
+            url = url + "?project_id=" + project_id
+
+        return self._list(url, "credits")