Improve exception handling, comments and naming

zaza/openstack/charm_tests/ceph/rbd_mirror/tests.py

@@ -184,14 +184,14 @@ class CephRBDMirrorBase(test_utils.BaseCharmTest):
         # get ready for multi-model Zaza
         cls.site_a_model = cls.site_b_model = zaza.model.get_juju_model()
         cls.site_b_app_suffix = '-b'
-        # Test if we have the needed Openstack applications.
+        # Test if we have the cinder-ceph application.
         try:
             zaza.model.get_application(cls.cinder_ceph_app_name)
             cls.with_cinder = True
-        except Exception:
+        except KeyError:
             cls.with_cinder = False
 
-    def check_cinder_present(self, caller):
+    def skip_test_if_cinder_not_present(self, caller):
         """Skip a test if Cinder isn't present."""
         if not self.with_cinder:
             raise unittest.SkipTest('Skipping %s due to lack of Cinder'
@@ -425,7 +425,7 @@ class CephRBDMirrorTest(CephRBDMirrorBase):
         site B and subsequently comparing the contents we get a full end to end
         test.
         """
-        self.check_cinder_present('test_cinder_volume_mirrored')
+        self.skip_test_if_cinder_not_present('test_cinder_volume_mirrored')
         volume = self.setup_test_cinder_volume()
         site_a_hash = zaza.openstack.utilities.ceph.get_rbd_hash(
             zaza.model.get_lead_unit_name('ceph-mon',
@@ -567,7 +567,7 @@ class CephRBDMirrorControlledFailoverTest(CephRBDMirrorBase):
         This test only makes sense if Cinder RBD mirroring mode is 'image'.
         It will return early, if this is not the case.
         """
-        self.check_cinder_present('test_100_cinder_failover')
+        self.skip_test_if_cinder_not_present('test_100_cinder_failover')
         cinder_rbd_mirroring_mode = get_cinder_rbd_mirroring_mode(
             self.cinder_ceph_app_name)
         if cinder_rbd_mirroring_mode != 'image':
@@ -617,7 +617,7 @@ class CephRBDMirrorControlledFailoverTest(CephRBDMirrorBase):
         The test needs to be executed when the Cinder volume host is already
         failed-over with the test volume on it.
         """
-        self.check_cinder_present('test_101_cinder_failback')
+        self.skip_test_if_cinder_not_present('test_101_cinder_failback')
         cinder_rbd_mirroring_mode = get_cinder_rbd_mirroring_mode(
             self.cinder_ceph_app_name)
         if cinder_rbd_mirroring_mode != 'image':
@@ -827,7 +827,7 @@ class CephRBDMirrorDisasterFailoverTest(CephRBDMirrorBase):
 
         This assumes that the primary site is already killed.
         """
-        self.check_cinder_present('test_200_forced_cinder_failover')
+        self.skip_test_if_cinder_not_present('test_200_forced_cinder_failover')
         cinder_rbd_mirroring_mode = get_cinder_rbd_mirroring_mode(
             self.cinder_ceph_app_name)
         if cinder_rbd_mirroring_mode != 'image':