Add Python 3.10 support and tests (#9077)

Fixes https://github.com/certbot/certbot/issues/9058.

The changes to the CI config are equivalent to the ones made in https://github.com/certbot/certbot/pull/8460.

Other than ignoring some warnings raised by botocore, the main additional work that had to be done here was switching away from using `distutils.version.LooseVersion` since the entire `distutils` module was deprecated in Python 3.10. To do that, I took a few different approaches:

* If the version strings being parsed are from Python packages such as Certbot or setuptools, I switched to using [pkg_resources.parse_version](https://setuptools.pypa.io/en/latest/pkg_resources.html#parsing-utilities) from `setuptools`. This functionality has been available since [setuptools 8.0 from 2014](https://setuptools.pypa.io/en/latest/history.html#id865).
* If the version strings being parsed are not from Python packages, I added code equivalent to `distutils.version.LooseVersion` in `certbot.util.parse_loose_version`.
* The code for `CERTBOT_PIP_NO_BINARY` can be completely removed since that variable isn't used or referenced anywhere in this repo.

* add python 3.10 support

* make some version changes

* don't use looseversion in setup.py

* switch to pkg_resources

* deprecate get_strict_version

* fix route53 tests

* remove unused CERTBOT_PIP_NO_BINARY code

* stop using distutils in letstest

* add unit tests

* more changelog entries

certbot/CHANGELOG.md

@@ -6,11 +6,15 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
 
 ### Added
 
-*
+* Support for Python 3.10 was added to Certbot and all of its components.
+* The function certbot.util.parse_loose_version was added to parse version
+  strings in the same way as the now deprecated distutils.version.LooseVersion
+  class from the Python standard library.
 
 ### Changed
 
-*
+* The function certbot.util.get_strict_version was deprecated and will be
+  removed in a future release.
 
 ### Fixed
 

certbot/certbot/_internal/storage.py

@@ -12,6 +12,7 @@ from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives.asymmetric.rsa import RSAPrivateKey
 from cryptography.hazmat.primitives.serialization import load_pem_private_key
 import parsedatetime
+import pkg_resources
 import pytz
 
 import certbot
@@ -33,7 +34,7 @@ logger = logging.getLogger(__name__)
 
 ALL_FOUR = ("cert", "privkey", "chain", "fullchain")
 README = "README"
-CURRENT_VERSION = util.get_strict_version(certbot.__version__)
+CURRENT_VERSION = pkg_resources.parse_version(certbot.__version__)
 BASE_PRIVKEY_MODE = 0o600
 
 
@@ -457,7 +458,7 @@ class RenewableCert(interfaces.RenewableCert):
 
         conf_version = self.configuration.get("version")
         if (conf_version is not None and
-                util.get_strict_version(conf_version) > CURRENT_VERSION):
+                pkg_resources.parse_version(conf_version) > CURRENT_VERSION):
             logger.info(
                 "Attempting to parse the version %s renewal configuration "
                 "file found at %s with version %s of Certbot. This might not "

certbot/certbot/util.py

@@ -1,10 +1,7 @@
 """Utilities for all Certbot."""
-# distutils.version under virtualenv confuses pylint
-# For more info, see: https://github.com/PyCQA/pylint/issues/73
 import argparse
 import atexit
 import collections
-import distutils.version
 import errno
 import logging
 import platform
@@ -14,6 +11,7 @@ import subprocess
 import sys
 from typing import Dict
 from typing import IO
+from typing import List
 from typing import Text
 from typing import Tuple
 from typing import Union
@@ -61,7 +59,7 @@ _INITIAL_PID = os.getpid()
 # program exits before the lock is cleaned up, it is automatically
 # released, but the file isn't deleted.
 _LOCKS: Dict[str, lock.LockFile] = {}
-
+_VERSION_COMPONENT_RE = re.compile(r'(\d+ | [a-z]+ | \.)', re.VERBOSE)
 
 def env_no_snap_for_external_calls():
     """
@@ -612,8 +610,13 @@ def get_strict_version(normalized):
     :rtype: distutils.version.StrictVersion
 
     """
-    # strict version ending with "a" and a number designates a pre-release
-    return distutils.version.StrictVersion(normalized.replace(".dev", "a"))
+    warnings.warn("certbot.util.get_strict_version is deprecated and will be "
+                  "removed in a future release.", DeprecationWarning)
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore", DeprecationWarning)
+        import distutils.version
+        # strict version ending with "a" and a number designates a pre-release
+        return distutils.version.StrictVersion(normalized.replace(".dev", "a"))
 
 
 def is_staging(srv):
@@ -639,6 +642,32 @@ def atexit_register(func, *args, **kwargs):
     atexit.register(_atexit_call, func, *args, **kwargs)
 
 
+def parse_loose_version(version_string):
+    """Parses a version string into its components.
+
+    This code and the returned tuple is based on the now deprecated
+    distutils.version.LooseVersion class from the Python standard library.
+    Two LooseVersion classes and two lists as returned by this function should
+    compare in the same way. See
+    https://github.com/python/cpython/blob/v3.10.0/Lib/distutils/version.py#L205-L347.
+
+    :param str version_string: version string
+
+    :returns: list of parsed version string components
+    :rtype: list
+
+    """
+    components: List[Union[int, str]]
+    components = [x for x in _VERSION_COMPONENT_RE.split(version_string)
+                          if x and x != '.']
+    for i, obj in enumerate(components):
+        try:
+            components[i] = int(obj)
+        except ValueError:
+            pass
+    return components
+
+
 def _atexit_call(func, *args, **kwargs):
     if _INITIAL_PID == os.getpid():
         func(*args, **kwargs)

certbot/setup.py

@@ -1,9 +1,9 @@
 import codecs
-from distutils.version import LooseVersion
 import os
 import re
 import sys
 
+from pkg_resources import parse_version
 from setuptools import __version__ as setuptools_version
 from setuptools import find_packages
 from setuptools import setup
@@ -11,7 +11,7 @@ from setuptools import setup
 min_setuptools_version='39.0.1'
 # This conditional isn't necessary, but it provides better error messages to
 # people who try to install this package with older versions of setuptools.
-if LooseVersion(setuptools_version) < LooseVersion(min_setuptools_version):
+if parse_version(setuptools_version) < parse_version(min_setuptools_version):
     raise RuntimeError(f'setuptools {min_setuptools_version}+ is required')
 
 # Workaround for https://bugs.python.org/issue8876, see
@@ -132,6 +132,7 @@ setup(
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
         'Topic :: Internet :: WWW/HTTP',
         'Topic :: Security',
         'Topic :: System :: Installation/Setup',

certbot/tests/util_test.py

@@ -592,6 +592,19 @@ class OsInfoTest(unittest.TestCase):
         self.assertEqual(cbutil.get_python_os_info(), ("testdist", "42"))
 
 
+class GetStrictVersionTest(unittest.TestCase):
+    """Test for certbot.util.get_strict_version."""
+
+    @classmethod
+    def _call(cls, *args, **kwargs):
+        from certbot.util import get_strict_version
+        return get_strict_version(*args, **kwargs)
+
+    def test_it(self):
+        with self.assertWarnsRegex(DeprecationWarning, "get_strict_version"):
+            self._call("1.2.3")
+
+
 class AtexitRegisterTest(unittest.TestCase):
     """Tests for certbot.util.atexit_register."""
     def setUp(self):
@@ -624,5 +637,38 @@ class AtexitRegisterTest(unittest.TestCase):
             atexit_func(*args[1:], **kwargs)
 
 
+class ParseLooseVersionTest(unittest.TestCase):
+    """Test for certbot.util.parse_loose_version.
+
+    These tests are based on the original tests for
+    distutils.version.LooseVersion at
+    https://github.com/python/cpython/blob/v3.10.0/Lib/distutils/tests/test_version.py#L58-L81.
+
+    """
+
+    @classmethod
+    def _call(cls, *args, **kwargs):
+        from certbot.util import parse_loose_version
+        return parse_loose_version(*args, **kwargs)
+
+    def test_less_than(self):
+        comparisons = (('1.5.1', '1.5.2b2'),
+            ('3.4j', '1996.07.12'),
+            ('2g6', '11g'),
+            ('0.960923', '2.2beta29'),
+            ('1.13++', '5.5.kw'))
+        for v1, v2 in comparisons:
+            self.assertLess(self._call(v1), self._call(v2))
+
+    def test_equal(self):
+        self.assertEqual(self._call('8.02'), self._call('8.02'))
+
+    def test_greater_than(self):
+        comparisons = (('161', '3.10a'),
+            ('3.2.pl0', '3.1.1.6'))
+        for v1, v2 in comparisons:
+            self.assertGreater(self._call(v1), self._call(v2))
+
+
 if __name__ == "__main__":
     unittest.main()  # pragma: no cover