Add attach_encrypted_volume to compute-feature-enabled

Change-Id: I491564fbe8c3be73a1475d99db25f7bcd7a13e3e
diff --git a/_modules/runtest/tempest_sections/compute_feature_enabled.py b/_modules/runtest/tempest_sections/compute_feature_enabled.py
index 6f787f9..3f53c01 100644
--- a/_modules/runtest/tempest_sections/compute_feature_enabled.py
+++ b/_modules/runtest/tempest_sections/compute_feature_enabled.py
@@ -44,7 +44,11 @@
 
     @property
     def attach_encrypted_volume(self):
-        pass
+        compute_check = conditions.BaseRule('*.nova.compute.enabled', 'eq', True)
+        cinder_check = conditions.BaseRule('*.cinder.controller.enabled', 'eq', True)
+        if compute_check.check(self.pillar) and cinder_check.check(self.pillar):
+            c = conditions.BaseRule('nova.controller.enabled', 'eq', True)
+            return self.get_item_when_condition_match('nova.controller.barbican.enabled', c)
 
     @property
     def block_migrate_cinder_iscsi(self):