Deprecate support for Python 2 (#8491)

Fixes #8388

* Deprecate support for Python 2

* Ignore deprecation warning

* Update certbot/CHANGELOG.md

Co-authored-by: Brad Warren <bmw@users.noreply.github.com>

acme/acme/__init__.py

@@ -6,6 +6,7 @@ This module is an implementation of the `ACME protocol`_.
 
 """
 import sys
+import warnings
 
 # This code exists to keep backwards compatibility with people using acme.jose
 # before it became the standalone josepy package.
@@ -19,3 +20,10 @@ for mod in list(sys.modules):
     # preserved (acme.jose.* is josepy.*)
     if mod == 'josepy' or mod.startswith('josepy.'):
         sys.modules['acme.' + mod.replace('josepy', 'jose', 1)] = sys.modules[mod]
+
+if sys.version_info[0] == 2:
+    warnings.warn(
+        "Python 2 support will be dropped in the next release of acme. "
+        "Please upgrade your Python version.",
+        PendingDeprecationWarning,
+    )  # pragma: no cover

certbot/CHANGELOG.md

@@ -10,6 +10,8 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
 
 ### Changed
 
+* We deprecated support for Python 2 in Certbot and its ACME library.
+  Support for Python 2 will be removed in the next planned release of Certbot.
 * certbot-auto was deprecated on all systems.
 
 ### Fixed

certbot/certbot/__init__.py

@@ -1,4 +1,13 @@
 """Certbot client."""
+import warnings
+import sys
 
 # version number like 1.2.3a0, must have at least 2 parts, like 1.2
 __version__ = '1.11.0.dev0'
+
+if sys.version_info[0] == 2:
+    warnings.warn(
+        "Python 2 support will be dropped in the next release of Certbot. "
+        "Please upgrade your Python version.",
+        PendingDeprecationWarning,
+    )  # pragma: no cover

certbot/certbot/_internal/main.py

@@ -5,6 +5,7 @@ from __future__ import print_function
 import functools
 import logging.handlers
 import sys
+import warnings
 
 import configobj
 import josepy as jose
@@ -1402,6 +1403,13 @@ def main(cli_args=None):
         if config.func != plugins_cmd:  # pylint: disable=comparison-with-callable
             raise
 
+    if sys.version_info[0] == 2:
+        warnings.warn(
+            "Python 2 support will be dropped in the next release of Certbot. "
+            "Please upgrade your Python version.",
+            PendingDeprecationWarning,
+        )  # pragma: no cover
+
     set_displayer(config)
 
     # Reporter

pytest.ini

@@ -4,6 +4,8 @@
 [pytest]
 # In general, all warnings are treated as errors. Here are the exceptions:
 #   1- decodestring: https://github.com/rthalley/dnspython/issues/338
+#   2- Python 2 deprecation: https://github.com/certbot/certbot/issues/8388
+#      (to be removed with Certbot 1.12.0 and its drop of Python 2 support)
 # Warnings being triggered by our plugins using deprecated features in
 # acme/certbot should be fixed by having our plugins no longer using the
 # deprecated code rather than adding them to the list of ignored warnings here.
@@ -14,3 +16,4 @@
 filterwarnings =
     error
     ignore:decodestring:DeprecationWarning
+    ignore:Python 2 support will be dropped:PendingDeprecationWarning