Use unittest.mock instead of third party mock

Now that we no longer support py27, we can use the standard library
unittest.mock module instead of the third party mock lib. Most of this
is autogenerated, as described below, but there is one manual change
necessary:

nova/tests/functional/regressions/test_bug_1781286.py
  We need to avoid using 'fixtures.MockPatch' since fixtures is using
  'mock' (the library) under the hood and a call to 'mock.patch.stop'
  found in that test will now "stop" mocks from the wrong library. We
  have discussed making this configurable but the option proposed isn't
  that pretty [1] so this is better.

The remainder was auto-generated with the following (hacky) script, with
one or two manual tweaks after the fact:

  import glob

  for path in glob.glob('nova/tests/**/*.py', recursive=True):
      with open(path) as fh:
          lines = fh.readlines()
      if 'import mock\n' not in lines:
          continue
      import_group_found = False
      create_first_party_group = False
      for num, line in enumerate(lines):
          line = line.strip()
          if line.startswith('import ') or line.startswith('from '):
              tokens = line.split()
              for lib in (
                  'ddt', 'six', 'webob', 'fixtures', 'testtools'
                  'neutron', 'cinder', 'ironic', 'keystone', 'oslo',
              ):
                  if lib in tokens[1]:
                      create_first_party_group = True
                      break
              if create_first_party_group:
                  break
              import_group_found = True
          if not import_group_found:
              continue
          if line.startswith('import ') or line.startswith('from '):
              tokens = line.split()
              if tokens[1] > 'unittest':
                  break
              elif tokens[1] == 'unittest' and (
                  len(tokens) == 2 or tokens[4] > 'mock'
              ):
                  break
          elif not line:
              break
      if create_first_party_group:
          lines.insert(num, 'from unittest import mock\n\n')
      else:
          lines.insert(num, 'from unittest import mock\n')
      del lines[lines.index('import mock\n')]
      with open(path, 'w+') as fh:
          fh.writelines(lines)

Note that we cannot remove mock from our requirements files yet due to
importing pypowervm unit test code in nova unit tests. This library
still uses the mock lib, and since we are importing test code and that
lib (correctly) only declares mock in its test-requirements.txt, mock
would not otherwise be installed and would cause errors while loading
nova unit test code.

[1] testing-cabal/fixtures#49

Change-Id: Id5b04cf2f6ca24af8e366d23f15cf0e5cac8e1cc
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

nova/test.py

@@ -35,9 +35,9 @@
 import os.path
 import pprint
 import sys
+from unittest import mock
 
 import fixtures
-import mock
 from oslo_cache import core as cache
 from oslo_concurrency import lockutils
 from oslo_config import cfg

nova/tests/fixtures/libvirt.py

@@ -18,10 +18,10 @@
 import textwrap
 import time
 import typing as ty
+from unittest import mock
 
 import fixtures
 from lxml import etree
-import mock
 from oslo_log import log as logging
 from oslo_utils.fixture import uuidsentinel as uuids
 from oslo_utils import versionutils

nova/tests/fixtures/libvirt_imagebackend.py

@@ -16,9 +16,9 @@
 import collections
 import functools
 import os
+from unittest import mock
 
 import fixtures
-import mock
 
 from nova.virt.libvirt import config
 from nova.virt.libvirt import driver

nova/tests/fixtures/nova.py

@@ -22,12 +22,14 @@
 import functools
 import logging as std_logging
 import os
+import time
+from unittest import mock
 import warnings
 
 import eventlet
 import fixtures
 import futurist
-import mock
+import mock as mock_the_lib
 from openstack import service_description
 from oslo_concurrency import lockutils
 from oslo_config import cfg
@@ -1587,7 +1589,14 @@ def fail(*a, **k):
                 current = __import__(components[0], {}, {})
                 for component in components[1:]:
                     current = getattr(current, component)
-                if not isinstance(getattr(current, attribute), mock.Mock):
+
+                # TODO(stephenfin): Remove mock_the_lib check once pypowervm is
+                # no longer using mock and we no longer have mock in
+                # requirements
+                if not isinstance(
+                    getattr(current, attribute),
+                    (mock.Mock, mock_the_lib.Mock),
+                ):
                     self.useFixture(fixtures.MonkeyPatch(
                         meth, poison_configure(meth, why)))
             except ImportError:

nova/tests/fixtures/os_brick.py

@@ -10,8 +10,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 import fixtures
-import mock
 
 from os_brick.initiator import connector as brick_connector
 

nova/tests/functional/api_sample_tests/test_baremetal_nodes.py

@@ -12,7 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
 
 from nova.tests.functional.api_sample_tests import api_sample_base
 

nova/tests/functional/api_sample_tests/test_compare_result.py

@@ -13,8 +13,8 @@
 #    under the License.
 
 import copy
+from unittest import mock
 
-import mock
 import testtools
 
 from nova import test

nova/tests/functional/api_sample_tests/test_create_backup.py

@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
 
 from nova.tests import fixtures
 from nova.tests.functional.api_sample_tests import test_servers

nova/tests/functional/api_sample_tests/test_evacuate.py

@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
 
 from nova import objects
 from nova.tests.functional.api_sample_tests import test_servers

nova/tests/functional/api_sample_tests/test_hypervisors.py

@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
 
 from nova.tests.functional.api_sample_tests import api_sample_base
 

nova/tests/functional/api_sample_tests/test_migrate_server.py

@@ -13,7 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
+
 from oslo_utils import versionutils
 
 from nova import exception

nova/tests/functional/api_sample_tests/test_networks.py

@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
 
 from nova import exception
 from nova.tests import fixtures as nova_fixtures

nova/tests/functional/api_sample_tests/test_server_migrations.py

@@ -14,9 +14,9 @@
 #    under the License.
 
 import datetime
+from unittest import mock
 
 import futurist
-import mock
 
 from nova.conductor import manager as conductor_manager
 from nova import context

nova/tests/functional/api_sample_tests/test_server_password.py

@@ -12,7 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
 
 from nova.tests.functional.api_sample_tests import test_servers
 

nova/tests/functional/api_sample_tests/test_simple_tenant_usage.py

@@ -13,9 +13,9 @@
 #    under the License.
 
 import datetime
+from unittest import mock
 from urllib import parse
 
-import mock
 from oslo_utils import timeutils
 
 from nova.tests.functional.api_sample_tests import test_servers

nova/tests/functional/compute/test_init_host.py

@@ -10,8 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import mock
 import time
+from unittest import mock
 
 from nova import context as nova_context
 from nova import objects

nova/tests/functional/compute/test_live_migration.py

@@ -12,7 +12,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import mock
+from unittest import mock
+
 from oslo_serialization import jsonutils
 from oslo_utils.fixture import uuidsentinel as uuids
 

nova/tests/functional/compute/test_resource_tracker.py

@@ -12,9 +12,9 @@
 
 import copy
 import os
+from unittest import mock
 
 import fixtures
-import mock
 import os_resource_classes as orc
 import os_traits
 from oslo_utils.fixture import uuidsentinel as uuids

nova/tests/functional/db/test_aggregate.py

@@ -11,8 +11,8 @@
 #    under the License.
 
 from copy import deepcopy
+from unittest import mock
 
-import mock
 from oslo_db import exception as db_exc
 from oslo_utils.fixture import uuidsentinel
 from oslo_utils import timeutils

nova/tests/functional/db/test_compute_api.py

@@ -10,7 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
+
 from oslo_utils.fixture import uuidsentinel as uuids
 
 from nova.compute import api as compute_api

nova/tests/functional/db/test_host_mapping.py

@@ -10,7 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
+
 from oslo_utils.fixture import uuidsentinel as uuids
 from oslo_utils import uuidutils
 

nova/tests/functional/db/test_instance_group.py

@@ -10,7 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
+
 from oslo_utils.fixture import uuidsentinel as uuids
 from oslo_versionedobjects import fixture as ovo_fixture
 

nova/tests/functional/db/test_instance_mapping.py

@@ -10,7 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
+
 from oslo_utils.fixture import uuidsentinel
 from oslo_utils import uuidutils
 

nova/tests/functional/db/test_quota.py

@@ -10,8 +10,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 import ddt
-import mock
 from oslo_utils import uuidutils
 
 from nova import context

nova/tests/functional/db/test_virtual_interface.py

@@ -11,7 +11,8 @@
 #    under the License.
 
 import datetime
-import mock
+from unittest import mock
+
 from oslo_config import cfg
 from oslo_utils import timeutils
 

nova/tests/functional/libvirt/base.py

@@ -15,9 +15,9 @@
 
 import copy
 import io
+from unittest import mock
 
 import fixtures
-import mock
 
 from nova import conf
 from nova.tests import fixtures as nova_fixtures

nova/tests/functional/libvirt/test_evacuate.py

@@ -13,10 +13,10 @@
 # under the License.
 
 import collections
-import fixtures
-import mock
 import os.path
+from unittest import mock
 
+import fixtures
 from oslo_utils import fileutils
 from oslo_utils.fixture import uuidsentinel as uuids
 from oslo_utils import units

nova/tests/functional/libvirt/test_numa_servers.py

@@ -13,11 +13,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
-import testtools
+from unittest import mock
 
 from oslo_config import cfg
 from oslo_log import log as logging
+import testtools
 
 import nova
 from nova.compute import manager

nova/tests/functional/libvirt/test_pci_sriov_servers.py

@@ -14,12 +14,12 @@
 #    under the License.
 
 import copy
+from unittest import mock
 from urllib import parse as urlparse
 
 import ddt
 import fixtures
 from lxml import etree
-import mock
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_serialization import jsonutils

nova/tests/functional/libvirt/test_report_cpu_traits.py

@@ -13,11 +13,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
+
 import os_resource_classes as orc
 import os_traits as ost
 
-
 from nova import conf
 from nova.db import constants as db_const
 from nova import test

nova/tests/functional/libvirt/test_reshape.py

@@ -12,7 +12,7 @@
 #    under the License.
 
 import io
-import mock
+from unittest import mock
 
 from oslo_config import cfg
 from oslo_log import log as logging

nova/tests/functional/libvirt/test_vtpm.py

@@ -13,7 +13,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import mock
+from unittest import mock
 
 from castellan.common.objects import passphrase
 from castellan.key_manager import key_manager

nova/tests/functional/notification_sample_tests/notification_sample_base.py

@@ -12,9 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
 import os
 import time
+from unittest import mock
 
 from oslo_config import cfg
 from oslo_serialization import jsonutils

nova/tests/functional/notification_sample_tests/test_instance.py

@@ -11,8 +11,8 @@
 #    under the License.
 
 import time
+from unittest import mock
 
-import mock
 
 from nova import exception
 from nova.tests import fixtures

nova/tests/functional/notification_sample_tests/test_libvirt.py

@@ -12,8 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 import fixtures
-import mock
 
 import nova.conf
 from nova import exception