Add quota delete test to cinder

This submission is to validate delete quota set in
volumes quota set test case. Hence added delete quota
set method in both XMl and JSON interfaces.

Change-Id: I217355bfc7696b93bc1f1388635cbb9bf8850199
diff --git a/tempest/api/volume/admin/test_volume_quotas.py b/tempest/api/volume/admin/test_volume_quotas.py
index 531e145..ecd8836 100644
--- a/tempest/api/volume/admin/test_volume_quotas.py
+++ b/tempest/api/volume/admin/test_volume_quotas.py
@@ -15,6 +15,7 @@
 #    under the License.
 
 from tempest.api.volume import base
+from tempest.common.utils import data_utils
 from tempest import test
 
 QUOTA_KEYS = ['gigabytes', 'snapshots', 'volumes']
@@ -99,6 +100,27 @@
         self.assertEqual(quota_usage['gigabytes']['in_use'] + 1,
                          new_quota_usage['gigabytes']['in_use'])
 
+    @test.attr(type='gate')
+    def test_delete_quota(self):
+        # Admin can delete the resource quota set for a tenant
+        tenant_name = data_utils.rand_name('quota_tenant_')
+        identity_client = self.os_adm.identity_client
+        tenant = identity_client.create_tenant(tenant_name)[1]
+        tenant_id = tenant['id']
+        self.addCleanup(identity_client.delete_tenant, tenant_id)
+        _, quota_set_default = self.quotas_client.get_default_quota_set(
+            tenant_id)
+        volume_default = quota_set_default['volumes']
+
+        self.quotas_client.update_quota_set(tenant_id,
+                                            volumes=(int(volume_default) + 5))
+
+        resp, _ = self.quotas_client.delete_quota_set(tenant_id)
+        self.assertEqual(200, resp.status)
+
+        _, quota_set_new = self.quotas_client.get_quota_set(tenant_id)
+        self.assertEqual(volume_default, quota_set_new['volumes'])
+
 
 class VolumeQuotasAdminTestXML(VolumeQuotasAdminTestJSON):
     _interface = "xml"
diff --git a/tempest/services/volume/json/admin/volume_quotas_client.py b/tempest/services/volume/json/admin/volume_quotas_client.py
index ea9c92e..961c7da 100644
--- a/tempest/services/volume/json/admin/volume_quotas_client.py
+++ b/tempest/services/volume/json/admin/volume_quotas_client.py
@@ -77,3 +77,7 @@
         post_body = jsonutils.dumps({'quota_set': post_body})
         resp, body = self.put('os-quota-sets/%s' % tenant_id, post_body)
         return resp, self._parse_resp(body)
+
+    def delete_quota_set(self, tenant_id):
+        """Delete the tenant's quota set."""
+        return self.delete('os-quota-sets/%s' % tenant_id)
diff --git a/tempest/services/volume/xml/admin/volume_quotas_client.py b/tempest/services/volume/xml/admin/volume_quotas_client.py
index dd1423f..a38410b 100644
--- a/tempest/services/volume/xml/admin/volume_quotas_client.py
+++ b/tempest/services/volume/xml/admin/volume_quotas_client.py
@@ -68,3 +68,7 @@
                               str(xml.Document(element)))
         body = xml.xml_to_json(etree.fromstring(body))
         return resp, self._format_quota(body)
+
+    def delete_quota_set(self, tenant_id):
+        """Delete the tenant's quota set."""
+        return self.delete('os-quota-sets/%s' % tenant_id)