XenAPI: Unit tests must mock os_xenapi calls

To prevent internal changes in os_xenapi from breaking nova unit
tests, we must mock os_xenapi calls (particular around session
management) rather than attempting to mock the internals of os_xenapi.
This issue was introduced when os_xenapi was split out from nova,
but the UT were not similarly abstracted

Change-Id: Ifdcddb63f64d5759640a62e8ddd3c276fa4fc743

nova/tests/unit/virt/xenapi/test_vmops.py

@@ -13,7 +13,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import base64
 import uuid
+import zlib
 
 try:
     import xmlrpclib
@@ -23,7 +25,6 @@ except ImportError:
 from eventlet import greenthread
 import mock
 from os_xenapi.client import host_xenstore
-from os_xenapi.client import session as xenapi_session
 import six
 
 from nova.compute import power_state
@@ -56,7 +57,7 @@ class VMOpsTestBase(stubs.XenAPITestBaseNoDB):
 
     def _setup_mock_vmops(self, product_brand=None, product_version=None):
         stubs.stubout_session(self.stubs, xenapi_fake.SessionBase)
-        self._session = xenapi_session.XenAPISession(
+        self._session = xenapi_fake.SessionBase(
             'http://localhost', 'root', 'test_pass')
         self.vmops = vmops.VMOps(self._session, fake.FakeVirtAPI())
 
@@ -235,8 +236,15 @@ class InjectAutoDiskConfigTestCase(VMOpsTestBase):
 
 
 class GetConsoleOutputTestCase(VMOpsTestBase):
-    def test_get_console_output_works(self):
+    def _mock_console_log(self, session, domid):
+        if domid == 0:
+            raise session.XenAPI.Failure('No console')
+        return base64.b64encode(zlib.compress(six.b('dom_id: %s' % domid)))
+
+    @mock.patch.object(vmops.vm_management, 'get_console_log')
+    def test_get_console_output_works(self, mock_console_log):
         ctxt = context.RequestContext('user', 'project')
+        mock_console_log.side_effect = self._mock_console_log
         instance = fake_instance.fake_instance_obj(ctxt)
         with mock.patch.object(self.vmops, '_get_last_dom_id',
                                return_value=42) as mock_last_dom:
@@ -244,7 +252,9 @@ class GetConsoleOutputTestCase(VMOpsTestBase):
                              self.vmops.get_console_output(instance))
             mock_last_dom.assert_called_once_with(instance, check_rescue=True)
 
-    def test_get_console_output_not_available(self):
+    @mock.patch.object(vmops.vm_management, 'get_console_log')
+    def test_get_console_output_not_available(self, mock_console_log):
+        mock_console_log.side_effect = self._mock_console_log
         ctxt = context.RequestContext('user', 'project')
         instance = fake_instance.fake_instance_obj(ctxt)
         # dom_id=0 used to trigger exception in fake XenAPI

nova/tests/unit/virt/xenapi/test_xenapi.py

@@ -25,7 +25,6 @@ import re
 import mock
 from mox3 import mox
 from os_xenapi.client import host_management
-from os_xenapi.client import session as xenapi_session
 from os_xenapi.client import XenAPI
 from oslo_concurrency import lockutils
 from oslo_config import fixture as config_fixture
@@ -143,8 +142,7 @@ IMAGE_FIXTURES = {
 
 
 def get_session():
-    return xenapi_session.XenAPISession(
-        'http://localhost', 'root', 'test_pass')
+    return xenapi_fake.SessionBase('http://localhost', 'root', 'test_pass')
 
 
 def set_image_fixtures():

nova/virt/xenapi/fake.py

@@ -360,6 +360,7 @@ def _create_local_pif(host_ref):
 def _create_object(table, obj):
     ref = uuidutils.generate_uuid()
     obj['uuid'] = uuidutils.generate_uuid()
+    obj['ref'] = ref
     _db_content[table][ref] = obj
     return ref
 
@@ -503,9 +504,11 @@ class Failure(Exception):
 class SessionBase(object):
     """Base class for Fake Sessions."""
 
-    def __init__(self, uri):
+    def __init__(self, uri, user=None, passwd=None):
         self._session = None
         xenapi_session.apply_session_helpers(self)
+        if user is not None:
+            self.xenapi.login_with_password(user, passwd)
 
     def pool_get_default_SR(self, _1, pool_ref):
         return list(_db_content['pool'].values())[0]['default-SR']
@@ -897,11 +900,21 @@ class SessionBase(object):
                     methodname)
             return meth(*full_params)
 
+    def call_xenapi(self, *args):
+        return self.xenapi_request(args[0], args[1:])
+
+    def get_all_refs_and_recs(self, cls):
+        return get_all_records(cls).items()
+
+    def get_rec(self, cls, ref):
+        return _db_content[cls].get(ref, None)
+
     def _login(self, method, params):
         self._session = uuidutils.generate_uuid()
         _session_info = {'uuid': uuidutils.generate_uuid(),
                          'this_host': list(_db_content['host'])[0]}
         _db_content['session'][self._session] = _session_info
+        self.host_ref = list(_db_content['host'])[0]
 
     def _logout(self):
         s = self._session