Use unittest.mock instead of PyPI mock

Now that py2 is gone, oslotest dropped dependency on mock and will
soon affect Ussuri CI [1], let's use unittest.mock built in py3.

This also fixes py38 jobs and proactively prevents py36 and py37
failing due to [1]. This is because we never included mock in
test-requirements (but in lower-constraints where it does not
really belong at all) and instead relied on oslotest to bring
it in.

[1] https://review.opendev.org/716322

Change-Id: Iceedcc7ad0d087414f6f94dfc0235fda4754be63

5 files changed, 4 insertions, 5 deletions

diff --git a/kolla/tests/base.py b/kolla/tests/base.py
index 1c43b7619..94bdba509 100644
--- a/kolla/tests/base.py
+++ b/kolla/tests/base.py
@@ -11,9 +11,9 @@
 # limitations under the License.
 
 import os
+from unittest import mock
 
 import fixtures
-import mock
 from oslo_config import cfg
 from oslotest import base as oslotest_base
 
diff --git a/kolla/tests/test_build.py b/kolla/tests/test_build.py
index 5b3e981d6..b7f5c30c0 100644
--- a/kolla/tests/test_build.py
+++ b/kolla/tests/test_build.py
@@ -12,10 +12,10 @@
 
 import fixtures
 import itertools
-import mock
 import os
 import requests
 import sys
+from unittest import mock
 
 from kolla.cmd import build as build_cmd
 from kolla import exception
diff --git a/lower-constraints.txt b/lower-constraints.txt
index 2d24ad02b..33e8abcce 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -37,7 +37,6 @@ keystoneauth1==3.4.0
 linecache2==1.0.0
 MarkupSafe==1.0
 mccabe==0.2.1
-mock==2.0.0
 monotonic==1.4
 mox3==0.25.0
 msgpack==0.5.6
diff --git a/tests/test_build.py b/tests/test_build.py
index 632931ee4..c4a4a6aed 100644
--- a/tests/test_build.py
+++ b/tests/test_build.py
@@ -13,8 +13,8 @@
 import multiprocessing
 import os
 import sys
+from unittest.mock import patch
 
-from mock import patch
 from oslo_log import fixture as log_fixture
 from oslo_log import log as logging
 from oslotest import base
diff --git a/tests/test_set_config.py b/tests/test_set_config.py
index e4706c99d..7016d8fa3 100644
--- a/tests/test_set_config.py
+++ b/tests/test_set_config.py
@@ -13,9 +13,9 @@
 import copy
 import imp
 import json
-import mock
 import os.path
 import sys
+from unittest import mock
 
 from oslotest import base