Add test for Nova list-versions API

This commit adds a test that does a GET on the raw endpoint to
ensure that the nova version GET does the right thing.

Co-Authored-By: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>

Related-Bug: #1491579
Change-Id: I5ee09891cd1b62a87d25284be961c2027cdbd82a
diff --git a/tempest/services/compute/json/versions_client.py b/tempest/services/compute/json/versions_client.py
new file mode 100644
index 0000000..cbad02c
--- /dev/null
+++ b/tempest/services/compute/json/versions_client.py
@@ -0,0 +1,37 @@
+# Copyright (c) 2015 Hewlett-Packard Development Company, L.P.
+#
+# 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 oslo_serialization import jsonutils as json
+from six.moves import urllib
+
+from tempest.api_schema.response.compute.v2_1 import versions as schema
+from tempest.common import service_client
+
+
+class VersionsClient(service_client.ServiceClient):
+
+    def list_versions(self):
+        # NOTE: The URL which is gotten from keystone's catalog contains
+        # API version and project-id like "v2/{project-id}", but we need
+        # to access the URL which doesn't contain them for getting API
+        # versions. For that, here should use raw_request() instead of
+        # get().
+        endpoint = self.base_url
+        url = urllib.parse.urlparse(endpoint)
+        version_url = '%s://%s/' % (url.scheme, url.netloc)
+
+        resp, body = self.raw_request(version_url, 'GET')
+        body = json.loads(body)
+        self.validate_response(schema.list_versions, resp, body)
+        return service_client.ResponseBody(resp, body)