Feature flag: allow disabling 'manage snapshot' tests

Manage/unmanage snapshots is an optional feature of Cinder, not every
backend supports it. Thus we should disable the related tests by
default, and enable them on supported backends.

Change-Id: I77be1cf85a946bf72e852f6378f0d7b43af8023a

tempest/api/volume/admin/v2/test_snapshot_manage.py

@@ -32,9 +32,8 @@ class SnapshotManageAdminV2Test(base.BaseVolumeAdminTest):
     """
 
     @test.idempotent_id('0132f42d-0147-4b45-8501-cc504bbf7810')
-    @testtools.skipIf(CONF.volume.storage_protocol == 'ceph',
-                      'Currently, Ceph does not support '
-                      'unmanage/manage snapshot')
+    @testtools.skipUnless(CONF.volume_feature_enabled.manage_snapshot,
+                          "Manage snapshot tests are disabled")
     def test_unmanage_manage_snapshot(self):
         # Create a volume
         volume = self.create_volume()

tempest/config.py

@@ -804,6 +804,9 @@ VolumeFeaturesGroup = [
     cfg.BoolOpt('clone',
                 default=True,
                 help='Runs Cinder volume clone test'),
+    cfg.BoolOpt('manage_snapshot',
+                default=False,
+                help='Runs Cinder manage snapshot tests'),
     cfg.ListOpt('api_extensions',
                 default=['all'],
                 help='A list of enabled volume extensions with a special '