bug 929462: compile_diagnostics in xenapi erronously catch XenAPI.Failure

ensure we catch the right exception. Plus turn test_diagnostics into a
more thorough unit test.

Change-Id: I1aae28b9b3b942f08e419cd9cfa48dea003e96d9

MANIFEST.in

@@ -38,6 +38,7 @@ include nova/tests/api/ec2/public_key/*
 include nova/tests/db/nova.austin.sqlite
 include nova/tests/image/*.tar.gz
 include nova/tests/policy.json
+include nova/tests/xenapi/vm_rrd.xml
 include plugins/xenapi/README
 include plugins/xenapi/etc/xapi.d/plugins/objectstore
 include plugins/xenapi/etc/xapi.d/plugins/pluginlib_nova.py

nova/tests/test_xenapi.py

@@ -243,8 +243,25 @@ class XenAPIVMTestCase(test.TestCase):
         self.assertEqual(server_info[1], 'myaddress')
 
     def test_get_diagnostics(self):
+        def fake_get_rrd(host, vm_uuid):
+            with open('xenapi/vm_rrd.xml') as f:
+                return re.sub(r'\s', '', f.read())
+        self.stubs.Set(vm_utils, 'get_rrd', fake_get_rrd)
+
+        fake_diagnostics = {
+            'vbd_xvdb_write': '0.0',
+            'memory_target': '10961792000.0000',
+            'memory_internal_free': '3612860.6020',
+            'memory': '10961792000.0000',
+            'vbd_xvda_write': '0.0',
+            'cpu0': '0.0110',
+            'vif_0_tx': '752.4007',
+            'vbd_xvda_read': '0.0',
+            'vif_0_rx': '4837.8805'
+        }
         instance = self._create_instance()
-        self.conn.get_diagnostics(instance)
+        expected = self.conn.get_diagnostics(instance)
+        self.assertDictMatch(fake_diagnostics, expected)
 
     def test_instance_snapshot_fails_with_no_primary_vdi(self):
         def create_bad_vbd(vm_ref, vdi_ref):

nova/virt/xenapi/fake.py

@@ -98,9 +98,11 @@ def create_pool(name_label):
                           {'name_label': name_label})
 
 
-def create_host(name_label):
+def create_host(name_label, hostname='fake_name', address='fake_addr'):
     return _create_object('host',
-                          {'name_label': name_label})
+                          {'name_label': name_label,
+                           'hostname': hostname,
+                           'address': address})
 
 
 def create_network(name_label, bridge):

nova/virt/xenapi/vm_utils.py

@@ -1037,7 +1037,8 @@ class VMHelper(HelperBase):
         """Compile VM diagnostics data"""
         try:
             diags = {}
-            xml = get_rrd(get_rrd_server(), record["uuid"])
+            vm_uuid = record["uuid"]
+            xml = get_rrd(get_rrd_server(), vm_uuid)
             if xml:
                 rrd = minidom.parseString(xml)
                 for i, node in enumerate(rrd.firstChild.childNodes):
@@ -1049,7 +1050,8 @@ class VMHelper(HelperBase):
                             _ref_zero = ref[0].firstChild.data
                             diags[_ref_zero] = ref[6].firstChild.data
             return diags
-        except cls.XenAPI.Failure as e:
+        except expat.ExpatError as e:
+            LOG.exception(_('Unable to parse rrd of %(vm_uuid)s') % locals())
             return {"Unable to retrieve diagnostics": e}
 
     @classmethod