Fix ovn_present for ovn-dedicated-chassis

Add missing unit test.

unit_tests/utilities/test_zaza_utilities_openstack.py

@@ -1202,4 +1202,10 @@ class TestOpenStackUtils(ut_utils.BaseTestCase):
             'neutron-api', 'enable-dvr')
 
     def test_ovn_present(self):
-        pass
+        self.patch_object(openstack_utils.model, 'get_application')
+        self.get_application.side_effect = [None, KeyError]
+        self.assertTrue(openstack_utils.ovn_present())
+        self.get_application.side_effect = [KeyError, None]
+        self.assertTrue(openstack_utils.ovn_present())
+        self.get_application.side_effect = [KeyError, KeyError]
+        self.assertFalse(openstack_utils.ovn_present())

zaza/openstack/utilities/openstack.py

@@ -477,15 +477,14 @@ def ovn_present():
     :returns: True when OVN is present, False otherwise
     :rtype: bool
     """
-    try:
-        for name in ('ovn-chassis', 'ovn-dedicated-chassis'):
+    app_presence = []
+    for name in ('ovn-chassis', 'ovn-dedicated-chassis'):
+        try:
             model.get_application(name)
-            return True
-    except KeyError:
-        return False
-    else:
-        raise RuntimeError('Unable to determine whether or not OVN is present '
-                           'in deployment')
+            app_presence.append(True)
+        except KeyError:
+            app_presence.append(False)
+    return any(app_presence)
 
 
 BRIDGE_MAPPINGS = 'bridge-mappings'