Drop xenapi session.get_imported_xenapi()

Historically it was used to allow the xenapi fake module to be inserted
in place of the real XenAPI module. However, it was used inconsistently
and is unnecessary now that the session carries that information as well.

Remove it by using the session.XenAPI attribute consistently, and then
removing the stubs and ensuring that the fake module gets inserted
directly into sys.modules.

Change-Id: Id058e19eb7d932abf7b07a1e4324637a8d4b2ea6

nova/tests/test_xenapi.py

@@ -134,7 +134,7 @@ def stub_vm_utils_with_vdi_attached_here(function, should_return=True):
     return decorated_function
 
 
-class XenAPIVolumeTestCase(test.TestCase):
+class XenAPIVolumeTestCase(stubs.XenAPITestBase):
     """Unit tests for Volume operations."""
     def setUp(self):
         super(XenAPIVolumeTestCase, self).setUp()
@@ -147,7 +147,6 @@ class XenAPIVolumeTestCase(test.TestCase):
                 firewall_driver='nova.virt.xenapi.firewall.'
                                 'Dom0IptablesFirewallDriver')
         db_fakes.stub_out_db_instance_api(self.stubs)
-        xenapi_fake.reset()
         self.instance_values = {'id': 1,
                   'project_id': self.user_id,
                   'user_id': 'fake',
@@ -252,7 +251,7 @@ class XenAPIVolumeTestCase(test.TestCase):
                           '/dev/sdc')
 
 
-class XenAPIVMTestCase(test.TestCase):
+class XenAPIVMTestCase(stubs.XenAPITestBase):
     """Unit tests for VM operations."""
     def setUp(self):
         super(XenAPIVMTestCase, self).setUp()
@@ -262,7 +261,6 @@ class XenAPIVMTestCase(test.TestCase):
                    instance_name_template='%d',
                    firewall_driver='nova.virt.xenapi.firewall.'
                                    'Dom0IptablesFirewallDriver')
-        xenapi_fake.reset()
         xenapi_fake.create_local_srs()
         xenapi_fake.create_local_pifs()
         db_fakes.stub_out_db_instance_api(self.stubs)
@@ -868,7 +866,7 @@ class XenAPIDiffieHellmanTestCase(test.TestCase):
         self._test_encryption(''.join(['abcd' for i in xrange(1024)]))
 
 
-class XenAPIMigrateInstance(test.TestCase):
+class XenAPIMigrateInstance(stubs.XenAPITestBase):
     """Unit test for verifying migration-related actions."""
 
     def setUp(self):
@@ -880,7 +878,6 @@ class XenAPIMigrateInstance(test.TestCase):
                                 'Dom0IptablesFirewallDriver')
         stubs.stubout_session(self.stubs, stubs.FakeSessionForVMTests)
         db_fakes.stub_out_db_instance_api(self.stubs)
-        xenapi_fake.reset()
         xenapi_fake.create_network('fake', FLAGS.flat_network_bridge)
         self.user_id = 'fake'
         self.project_id = 'fake'
@@ -1122,7 +1119,7 @@ class CompareVersionTestCase(test.TestCase):
         self.assertTrue(vmops.cmp_version('1.2.3', '1.2.3.4') < 0)
 
 
-class XenAPIHostTestCase(test.TestCase):
+class XenAPIHostTestCase(stubs.XenAPITestBase):
     """Tests HostState, which holds metrics from XenServer that get
     reported back to the Schedulers."""
 
@@ -1131,7 +1128,6 @@ class XenAPIHostTestCase(test.TestCase):
         self.flags(xenapi_connection_url='test_url',
                    xenapi_connection_password='test_pass')
         stubs.stubout_session(self.stubs, stubs.FakeSessionForVMTests)
-        xenapi_fake.reset()
         xenapi_fake.create_local_srs()
         self.conn = xenapi_conn.XenAPIDriver(False)
 
@@ -1175,7 +1171,7 @@ class XenAPIHostTestCase(test.TestCase):
         self._test_host_action(self.conn.set_host_enabled, False, 'disabled')
 
 
-class XenAPIAutoDiskConfigTestCase(test.TestCase):
+class XenAPIAutoDiskConfigTestCase(stubs.XenAPITestBase):
     def setUp(self):
         super(XenAPIAutoDiskConfigTestCase, self).setUp()
         self.flags(target_host='127.0.0.1',
@@ -1184,7 +1180,6 @@ class XenAPIAutoDiskConfigTestCase(test.TestCase):
                    firewall_driver='nova.virt.xenapi.firewall.'
                                    'Dom0IptablesFirewallDriver')
         stubs.stubout_session(self.stubs, stubs.FakeSessionForVMTests)
-        xenapi_fake.reset()
         self.conn = xenapi_conn.XenAPIDriver(False)
 
         self.user_id = 'fake'
@@ -1266,7 +1261,7 @@ class XenAPIAutoDiskConfigTestCase(test.TestCase):
         self.assertIsPartitionCalled(True)
 
 
-class XenAPIGenerateLocal(test.TestCase):
+class XenAPIGenerateLocal(stubs.XenAPITestBase):
     """Test generating of local disks, like swap and ephemeral"""
     def setUp(self):
         super(XenAPIGenerateLocal, self).setUp()
@@ -1278,7 +1273,6 @@ class XenAPIGenerateLocal(test.TestCase):
                                    'Dom0IptablesFirewallDriver')
         stubs.stubout_session(self.stubs, stubs.FakeSessionForVMTests)
         db_fakes.stub_out_db_instance_api(self.stubs)
-        xenapi_fake.reset()
         self.conn = xenapi_conn.XenAPIDriver(False)
 
         self.user_id = 'fake'
@@ -1343,7 +1337,7 @@ class XenAPIGenerateLocal(test.TestCase):
         self.assertCalled(instance)
 
 
-class XenAPIBWUsageTestCase(test.TestCase):
+class XenAPIBWUsageTestCase(stubs.XenAPITestBase):
     def setUp(self):
         super(XenAPIBWUsageTestCase, self).setUp()
         self.stubs.Set(vm_utils, 'compile_metrics',
@@ -1354,7 +1348,6 @@ class XenAPIBWUsageTestCase(test.TestCase):
                    firewall_driver='nova.virt.xenapi.firewall.'
                                    'Dom0IptablesFirewallDriver')
         stubs.stubout_session(self.stubs, stubs.FakeSessionForVMTests)
-        xenapi_fake.reset()
         self.conn = xenapi_conn.XenAPIDriver(False)
 
     @classmethod
@@ -1378,7 +1371,7 @@ class XenAPIBWUsageTestCase(test.TestCase):
 # TODO(salvatore-orlando): this class and
 # nova.tests.test_libvirt.IPTablesFirewallDriverTestCase share a lot of code.
 # Consider abstracting common code in a base class for firewall driver testing.
-class XenAPIDom0IptablesFirewallTestCase(test.TestCase):
+class XenAPIDom0IptablesFirewallTestCase(stubs.XenAPITestBase):
 
     _in_nat_rules = [
       '# Generated by iptables-save v1.4.10 on Sat Feb 19 00:03:19 2011',
@@ -1424,7 +1417,6 @@ class XenAPIDom0IptablesFirewallTestCase(test.TestCase):
                    instance_name_template='%d',
                    firewall_driver='nova.virt.xenapi.firewall.'
                                    'Dom0IptablesFirewallDriver')
-        xenapi_fake.reset()
         xenapi_fake.create_local_srs()
         xenapi_fake.create_local_pifs()
         self.user_id = 'mappin'
@@ -1679,12 +1671,8 @@ class XenAPIDom0IptablesFirewallTestCase(test.TestCase):
         self.assertEqual(1, len(rules))
 
 
-class XenAPISRSelectionTestCase(test.TestCase):
+class XenAPISRSelectionTestCase(stubs.XenAPITestBase):
     """Unit tests for testing we find the right SR."""
-    def setUp(self):
-        super(XenAPISRSelectionTestCase, self).setUp()
-        xenapi_fake.reset()
-
     def test_safe_find_sr_raise_exception(self):
         """Ensure StorageRepositoryNotFound is raise when wrong filter."""
         self.flags(sr_matching_filter='yadayadayada')
@@ -1733,7 +1721,7 @@ class XenAPISRSelectionTestCase(test.TestCase):
                          expected)
 
 
-class XenAPIAggregateTestCase(test.TestCase):
+class XenAPIAggregateTestCase(stubs.XenAPITestBase):
     """Unit tests for aggregate operations."""
     def setUp(self):
         super(XenAPIAggregateTestCase, self).setUp()
@@ -1744,7 +1732,6 @@ class XenAPIAggregateTestCase(test.TestCase):
                    firewall_driver='nova.virt.xenapi.firewall.'
                                    'Dom0IptablesFirewallDriver',
                    host='host')
-        xenapi_fake.reset()
         host_ref = xenapi_fake.get_all('host')[0]
         stubs.stubout_session(self.stubs, stubs.FakeSessionForVMTests)
         self.context = context.get_admin_context()

nova/tests/test_xensm.py

@@ -35,7 +35,7 @@ LOG = logging.getLogger(__name__)
 FLAGS = flags.FLAGS
 
 
-class XenSMTestCase(test.TestCase):
+class XenSMTestCase(stubs.XenAPITestBase):
     """Unit tests for Xen Storage Manager Volume operations."""
 
     def _get_sm_backend_params(self):

nova/tests/xenapi/stubs.py

@@ -16,8 +16,10 @@
 """Stubouts, mocks and fixtures for the test suite"""
 
 import random
+import sys
 
 from nova.openstack.common import jsonutils
+from nova import test
 import nova.tests.image.fake
 from nova.virt.xenapi import connection as xenapi_conn
 from nova.virt.xenapi import fake
@@ -51,17 +53,9 @@ def stubout_instance_snapshot(stubs):
 
 
 def stubout_session(stubs, cls, product_version=(5, 6, 2), **opt_args):
-    """Stubs out three methods from XenAPISession"""
+    """Stubs out methods from XenAPISession"""
-    def fake_import(self):
-        """Stubs out get_imported_xenapi of XenAPISession"""
-        fake_module = 'nova.virt.xenapi.fake'
-        from_list = ['fake']
-        return __import__(fake_module, globals(), locals(), from_list, -1)
-
     stubs.Set(xenapi_conn.XenAPISession, '_create_session',
               lambda s, url: cls(url, **opt_args))
-    stubs.Set(xenapi_conn.XenAPISession, 'get_imported_xenapi',
-              fake_import)
     stubs.Set(xenapi_conn.XenAPISession, '_get_product_version',
               lambda s: product_version)
 
@@ -363,3 +357,22 @@ def stub_out_migration_methods(stubs):
     stubs.Set(vm_utils, 'get_vdi_for_vm_safely', fake_get_vdi)
     stubs.Set(vm_utils, 'get_sr_path', fake_get_sr_path)
     stubs.Set(vm_utils, 'generate_ephemeral', fake_generate_ephemeral)
+
+
+class XenAPITestBase(test.TestCase):
+    def setUp(self):
+        super(XenAPITestBase, self).setUp()
+
+        self.orig_XenAPI = sys.modules.get('XenAPI')
+        sys.modules['XenAPI'] = fake
+
+        fake.reset()
+
+    def tearDown(self):
+        if self.orig_XenAPI is not None:
+            sys.modules['XenAPI'] = self.orig_XenAPI
+            self.orig_XenAPI = None
+        else:
+            sys.modules.pop('XenAPI')
+
+        super(XenAPITestBase, self).tearDown()