Change database clients to return one value and update tests

Partially implements: blueprint clients-return-one-value

Change-Id: I132115b8e9ec3859469a2b502f862c9270b17884
diff --git a/tempest/api/database/flavors/test_flavors.py b/tempest/api/database/flavors/test_flavors.py
index bb7035b..db8939e 100644
--- a/tempest/api/database/flavors/test_flavors.py
+++ b/tempest/api/database/flavors/test_flavors.py
@@ -27,7 +27,7 @@
     @test.attr(type='smoke')
     def test_get_db_flavor(self):
         # The expected flavor details should be returned
-        _, flavor = self.client.get_db_flavor_details(self.db_flavor_ref)
+        flavor = self.client.get_db_flavor_details(self.db_flavor_ref)
         self.assertEqual(self.db_flavor_ref, str(flavor['id']))
         self.assertIn('ram', flavor)
         self.assertIn('links', flavor)
@@ -35,9 +35,9 @@
 
     @test.attr(type='smoke')
     def test_list_db_flavors(self):
-        _, flavor = self.client.get_db_flavor_details(self.db_flavor_ref)
+        flavor = self.client.get_db_flavor_details(self.db_flavor_ref)
         # List of all flavors should contain the expected flavor
-        _, flavors = self.client.list_db_flavors()
+        flavors = self.client.list_db_flavors()
         self.assertIn(flavor, flavors)
 
     def _check_values(self, names, db_flavor, os_flavor, in_db=True):
@@ -54,13 +54,13 @@
     @test.attr(type='smoke')
     @test.services('compute')
     def test_compare_db_flavors_with_os(self):
-        _, db_flavors = self.client.list_db_flavors()
+        db_flavors = self.client.list_db_flavors()
         os_flavors = self.os_flavors_client.list_flavors_with_detail()
         self.assertEqual(len(os_flavors), len(db_flavors),
                          "OS flavors %s do not match DB flavors %s" %
                          (os_flavors, db_flavors))
         for os_flavor in os_flavors:
-            _, db_flavor =\
+            db_flavor =\
                 self.client.get_db_flavor_details(os_flavor['id'])
             self._check_values(['id', 'name', 'ram'], db_flavor, os_flavor)
             self._check_values(['disk', 'vcpus', 'swap'], db_flavor, os_flavor,
diff --git a/tempest/api/database/limits/test_limits.py b/tempest/api/database/limits/test_limits.py
index 68a3884..d1c9baf 100644
--- a/tempest/api/database/limits/test_limits.py
+++ b/tempest/api/database/limits/test_limits.py
@@ -28,7 +28,7 @@
     def test_absolute_limits(self):
         # Test to verify if all absolute limit paramaters are
         # present when verb is ABSOLUTE
-        _, limits = self.client.list_db_limits()
+        limits = self.client.list_db_limits()
         expected_abs_limits = ['max_backups', 'max_volumes',
                                'max_instances', 'verb']
         absolute_limit = [l for l in limits
diff --git a/tempest/api/database/versions/test_versions.py b/tempest/api/database/versions/test_versions.py
index 37a7407..8960437 100644
--- a/tempest/api/database/versions/test_versions.py
+++ b/tempest/api/database/versions/test_versions.py
@@ -26,7 +26,7 @@
 
     @test.attr(type='smoke')
     def test_list_db_versions(self):
-        _, versions = self.client.list_db_versions()
+        versions = self.client.list_db_versions()
         self.assertTrue(len(versions) > 0, "No database versions found")
         # List of all versions should contain the current version, and there
         # should only be one 'current' version
diff --git a/tempest/services/database/json/flavors_client.py b/tempest/services/database/json/flavors_client.py
index dfb2eb3..c956e27 100644
--- a/tempest/services/database/json/flavors_client.py
+++ b/tempest/services/database/json/flavors_client.py
@@ -27,9 +27,9 @@
 
         resp, body = self.get(url)
         self.expected_success(200, resp.status)
-        return resp, self._parse_resp(body)
+        return service_client.ResponseBodyList(resp, self._parse_resp(body))
 
     def get_db_flavor_details(self, db_flavor_id):
         resp, body = self.get("flavors/%s" % str(db_flavor_id))
         self.expected_success(200, resp.status)
-        return resp, self._parse_resp(body)
+        return service_client.ResponseBody(resp, self._parse_resp(body))
diff --git a/tempest/services/database/json/limits_client.py b/tempest/services/database/json/limits_client.py
index 6168bfd..ae758bc 100644
--- a/tempest/services/database/json/limits_client.py
+++ b/tempest/services/database/json/limits_client.py
@@ -15,10 +15,10 @@
 
 import urllib
 
-from tempest_lib.common import rest_client
+from tempest.common import service_client
 
 
-class DatabaseLimitsClientJSON(rest_client.RestClient):
+class DatabaseLimitsClientJSON(service_client.ServiceClient):
 
     def list_db_limits(self, params=None):
         """List all limits."""
@@ -27,4 +27,4 @@
             url += '?%s' % urllib.urlencode(params)
         resp, body = self.get(url)
         self.expected_success(200, resp.status)
-        return resp, self._parse_resp(body)
+        return service_client.ResponseBodyList(resp, self._parse_resp(body))
diff --git a/tempest/services/database/json/versions_client.py b/tempest/services/database/json/versions_client.py
index c3388bb..aa2fef7 100644
--- a/tempest/services/database/json/versions_client.py
+++ b/tempest/services/database/json/versions_client.py
@@ -43,4 +43,4 @@
 
         resp, body = self.get(url)
         self.expected_success(200, resp.status)
-        return resp, self._parse_resp(body)
+        return service_client.ResponseBodyList(resp, self._parse_resp(body))