Remove mock dependency (#8630)

Fixes https://github.com/certbot/certbot/issues/7913.

I only added the deprecation warning to `certbot.tests.util` because that's the only place where I think someone could be using the `mock` module through our API.

* remove external mock from acme

* update Certbot's mock usage

* remove mock dependency in plugins

* remove external mock from compatibility test

* add changelog entry

29 files changed, 19 insertions, 244 deletions

diff --git a/acme/setup.py b/acme/setup.py
index c62562ff3..745169cbf 100644
--- a/acme/setup.py
+++ b/acme/setup.py
@@ -1,7 +1,5 @@
-from distutils.version import LooseVersion
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -23,15 +21,6 @@ install_requires = [
     'six>=1.11.0',
 ]
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 dev_extras = [
     'pytest',
     'pytest-xdist',
diff --git a/acme/tests/challenges_test.py b/acme/tests/challenges_test.py
index 70371051c..22e67be3c 100644
--- a/acme/tests/challenges_test.py
+++ b/acme/tests/challenges_test.py
@@ -1,12 +1,9 @@
 """Tests for acme.challenges."""
 import unittest
+from unittest import mock
 
 import josepy as jose
 import OpenSSL
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
 import requests
 from six.moves.urllib import parse as urllib_parse
 
diff --git a/acme/tests/client_test.py b/acme/tests/client_test.py
index c84878c42..a1be59056 100644
--- a/acme/tests/client_test.py
+++ b/acme/tests/client_test.py
@@ -4,12 +4,9 @@ import copy
 import datetime
 import json
 import unittest
+from unittest import mock
 
 import josepy as jose
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
 import OpenSSL
 import requests
 from six.moves import http_client  # pylint: disable=import-error
diff --git a/acme/tests/errors_test.py b/acme/tests/errors_test.py
index fb90a3f0d..11c57059c 100644
--- a/acme/tests/errors_test.py
+++ b/acme/tests/errors_test.py
@@ -1,10 +1,6 @@
 """Tests for acme.errors."""
 import unittest
-
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
+from unittest import mock
 
 
 class BadNonceTest(unittest.TestCase):
diff --git a/acme/tests/magic_typing_test.py b/acme/tests/magic_typing_test.py
index 9e4fd29f5..048995916 100644
--- a/acme/tests/magic_typing_test.py
+++ b/acme/tests/magic_typing_test.py
@@ -1,11 +1,7 @@
 """Tests for acme.magic_typing."""
 import sys
 import unittest
-
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
+from unittest import mock
 
 
 class MagicTypingTest(unittest.TestCase):
diff --git a/acme/tests/messages_test.py b/acme/tests/messages_test.py
index 70b05b419..74d1737ec 100644
--- a/acme/tests/messages_test.py
+++ b/acme/tests/messages_test.py
@@ -1,11 +1,8 @@
 """Tests for acme.messages."""
 import unittest
+from unittest import mock
 
 import josepy as jose
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
 
 from acme import challenges
 import test_util
diff --git a/acme/tests/standalone_test.py b/acme/tests/standalone_test.py
index 3d068fb46..5bbc2ccce 100644
--- a/acme/tests/standalone_test.py
+++ b/acme/tests/standalone_test.py
@@ -2,12 +2,9 @@
 import socket
 import threading
 import unittest
+from unittest import mock
 
 import josepy as jose
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
 import requests
 from six.moves import http_client  # pylint: disable=import-error
 from six.moves import socketserver  # type: ignore  # pylint: disable=import-error
diff --git a/certbot-apache/setup.py b/certbot-apache/setup.py
index 12aeac06b..f129343b3 100644
--- a/certbot-apache/setup.py
+++ b/certbot-apache/setup.py
@@ -1,7 +1,3 @@
-from distutils.version import LooseVersion
-import sys
-
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -18,15 +14,6 @@ install_requires = [
     'zope.interface',
 ]
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 dev_extras = [
     'apacheconfig>=0.3.2',
 ]
diff --git a/certbot-compatibility-test/certbot_compatibility_test/configurators/apache/common.py b/certbot-compatibility-test/certbot_compatibility_test/configurators/apache/common.py
index b6fbe2817..2b3f94581 100644
--- a/certbot-compatibility-test/certbot_compatibility_test/configurators/apache/common.py
+++ b/certbot-compatibility-test/certbot_compatibility_test/configurators/apache/common.py
@@ -2,11 +2,8 @@
 import os
 import shutil
 import subprocess
+from unittest import mock
 
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
 import zope.interface
 
 from certbot import errors as le_errors
diff --git a/certbot-compatibility-test/certbot_compatibility_test/validator_test.py b/certbot-compatibility-test/certbot_compatibility_test/validator_test.py
index 0b1056561..711d1b38e 100644
--- a/certbot-compatibility-test/certbot_compatibility_test/validator_test.py
+++ b/certbot-compatibility-test/certbot_compatibility_test/validator_test.py
@@ -1,10 +1,7 @@
 """Tests for certbot_compatibility_test.validator."""
 import unittest
+from unittest import mock
 
-try:
-    import mock
-except ImportError: # pragma: no cover
-    from unittest import mock # type: ignore
 import OpenSSL
 import requests
 
diff --git a/certbot-compatibility-test/setup.py b/certbot-compatibility-test/setup.py
index 19ee74efe..0236773f0 100644
--- a/certbot-compatibility-test/setup.py
+++ b/certbot-compatibility-test/setup.py
@@ -1,7 +1,5 @@
-from distutils.version import LooseVersion
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -15,15 +13,6 @@ install_requires = [
     'zope.interface',
 ]
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 if sys.version_info < (2, 7, 9):
     # For secure SSL connexion with Python 2.7 (InsecurePlatformWarning)
     install_requires.append('ndg-httpsclient')
diff --git a/certbot-dns-cloudflare/setup.py b/certbot-dns-cloudflare/setup.py
index b4f7222c0..eab6cdb70 100644
--- a/certbot-dns-cloudflare/setup.py
+++ b/certbot-dns-cloudflare/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-cloudxns/setup.py b/certbot-dns-cloudxns/setup.py
index e7ae702ef..83513ef7c 100644
--- a/certbot-dns-cloudxns/setup.py
+++ b/certbot-dns-cloudxns/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-digitalocean/setup.py b/certbot-dns-digitalocean/setup.py
index fca973e81..8c6ac78d5 100644
--- a/certbot-dns-digitalocean/setup.py
+++ b/certbot-dns-digitalocean/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -28,15 +26,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-dnsimple/setup.py b/certbot-dns-dnsimple/setup.py
index 329977aed..f1fcfd11d 100644
--- a/certbot-dns-dnsimple/setup.py
+++ b/certbot-dns-dnsimple/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -26,15 +24,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 # This package normally depends on dns-lexicon>=3.2.1 to address the
 # problem described in https://github.com/AnalogJ/lexicon/issues/387,
 # however, the fix there has been backported to older versions of
diff --git a/certbot-dns-dnsmadeeasy/setup.py b/certbot-dns-dnsmadeeasy/setup.py
index def4ed1f0..185048a2d 100644
--- a/certbot-dns-dnsmadeeasy/setup.py
+++ b/certbot-dns-dnsmadeeasy/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-gehirn/setup.py b/certbot-dns-gehirn/setup.py
index a074b0eb2..0ae9c1bf7 100644
--- a/certbot-dns-gehirn/setup.py
+++ b/certbot-dns-gehirn/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -26,15 +24,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-google/setup.py b/certbot-dns-google/setup.py
index d104929b6..b16d014c6 100644
--- a/certbot-dns-google/setup.py
+++ b/certbot-dns-google/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -30,15 +28,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-linode/setup.py b/certbot-dns-linode/setup.py
index ddb9c2ef7..21ccf9d42 100644
--- a/certbot-dns-linode/setup.py
+++ b/certbot-dns-linode/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -26,15 +24,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-luadns/setup.py b/certbot-dns-luadns/setup.py
index 4b83ba2c0..2312d6fcc 100644
--- a/certbot-dns-luadns/setup.py
+++ b/certbot-dns-luadns/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-nsone/setup.py b/certbot-dns-nsone/setup.py
index 6ebe9decb..658027b9a 100644
--- a/certbot-dns-nsone/setup.py
+++ b/certbot-dns-nsone/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-ovh/setup.py b/certbot-dns-ovh/setup.py
index 9e7ec3675..b4f73ddb4 100644
--- a/certbot-dns-ovh/setup.py
+++ b/certbot-dns-ovh/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-rfc2136/setup.py b/certbot-dns-rfc2136/setup.py
index cd0766585..ce74611cd 100644
--- a/certbot-dns-rfc2136/setup.py
+++ b/certbot-dns-rfc2136/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-route53/setup.py b/certbot-dns-route53/setup.py
index 82cb50ddb..8def9a702 100644
--- a/certbot-dns-route53/setup.py
+++ b/certbot-dns-route53/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -27,15 +25,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-dns-sakuracloud/setup.py b/certbot-dns-sakuracloud/setup.py
index 6bb76b514..6f4f8e506 100644
--- a/certbot-dns-sakuracloud/setup.py
+++ b/certbot-dns-sakuracloud/setup.py
@@ -1,8 +1,6 @@
-from distutils.version import LooseVersion
 import os
 import sys
 
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -26,15 +24,6 @@ elif 'bdist_wheel' in sys.argv[1:]:
 if os.environ.get('SNAP_BUILD'):
     install_requires.append('packaging')
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 docs_extras = [
     'Sphinx>=1.0',  # autodoc_member_order = 'bysource', autodoc_default_flags
     'sphinx_rtd_theme',
diff --git a/certbot-nginx/setup.py b/certbot-nginx/setup.py
index 988f30052..385f4cc17 100644
--- a/certbot-nginx/setup.py
+++ b/certbot-nginx/setup.py
@@ -1,7 +1,3 @@
-from distutils.version import LooseVersion
-import sys
-
-from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
 
@@ -18,15 +14,6 @@ install_requires = [
     'zope.interface',
 ]
 
-setuptools_known_environment_markers = (LooseVersion(setuptools_version) >= LooseVersion('36.2'))
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 setup(
     name='certbot-nginx',
     version=version,
diff --git a/certbot/CHANGELOG.md b/certbot/CHANGELOG.md
index a4a53c88e..1333d2420 100644
--- a/certbot/CHANGELOG.md
+++ b/certbot/CHANGELOG.md
@@ -10,6 +10,10 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
 
 ### Changed
 
+* Certbot no longer conditionally depends on an external mock module. Certbot's
+  test API will continue to use it if it is available for backwards
+  compatibility, however, this behavior has been deprecated and will be removed
+  in a future release.
 * The acme library no longer depends on the `security` extras from `requests`
   which was needed to support SNI in TLS requests when using old versions of
   Python 2.
diff --git a/certbot/certbot/tests/util.py b/certbot/certbot/tests/util.py
index b9d5caa08..acb31819f 100644
--- a/certbot/certbot/tests/util.py
+++ b/certbot/certbot/tests/util.py
@@ -6,12 +6,19 @@ import shutil
 import sys
 import tempfile
 import unittest
+import warnings
 
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import serialization
 import josepy as jose
 try:
     import mock
+    warnings.warn(
+        "The external mock module is being used for backwards compatibility "
+        "since it is available, however, future versions of Certbot's tests will "
+        "use unittest.mock. Be sure to update your code accordingly.",
+        PendingDeprecationWarning
+    )
 except ImportError: # pragma: no cover
     from unittest import mock # type: ignore
 import OpenSSL
diff --git a/certbot/setup.py b/certbot/setup.py
index 0d80dfd05..4ea98e574 100644
--- a/certbot/setup.py
+++ b/certbot/setup.py
@@ -72,14 +72,6 @@ elif os.name == 'nt':
     # setuptools, pywin32 will not be specified as a dependency.
     install_requires.append(pywin32_req)
 
-if setuptools_known_environment_markers:
-    install_requires.append('mock ; python_version < "3.3"')
-elif 'bdist_wheel' in sys.argv[1:]:
-    raise RuntimeError('Error, you are trying to build certbot wheels using an old version '
-                       'of setuptools. Version 36.2+ of setuptools is required.')
-elif sys.version_info < (3,3):
-    install_requires.append('mock')
-
 dev_extras = [
     'astroid',
     'azure-devops',