fix various fd leaks (#8747)

* fix various fd leaks

* use context manager for display provider

certbot/certbot/_internal/main.py

@@ -4,6 +4,9 @@
 import functools
 import logging.handlers
 import sys
+from contextlib import contextmanager
+from typing import Generator
+from typing import IO
 from typing import Iterable
 from typing import List
 from typing import Optional
@@ -1347,26 +1350,36 @@ def make_or_verify_needed_dirs(config):
         util.make_or_verify_dir(hook_dir, strict=config.strict_permissions)
 
 
-def set_displayer(config):
-    """Set the displayer
+@contextmanager
+def make_displayer(config: configuration.NamespaceConfig
+                   ) -> Generator[Union[display_util.NoninteractiveDisplay,
+                                        display_util.FileDisplay], None, None]:
+    """Creates a display object appropriate to the flags in the supplied config.
 
     :param config: Configuration object
-    :type config: interfaces.IConfig
 
-    :returns: `None`
-    :rtype: None
+    :returns: Display object implementing :class:`certbot.interfaces.IDisplay`
 
     """
+    displayer: Union[None, display_util.NoninteractiveDisplay,
+                     display_util.FileDisplay] = None
+    devnull: Optional[IO] = None
+
     if config.quiet:
         config.noninteractive_mode = True
-        displayer: Union[None, display_util.NoninteractiveDisplay, display_util.FileDisplay] =\
-            display_util.NoninteractiveDisplay(open(os.devnull, "w"))
+        devnull = open(os.devnull, "w")
+        displayer = display_util.NoninteractiveDisplay(devnull)
     elif config.noninteractive_mode:
         displayer = display_util.NoninteractiveDisplay(sys.stdout)
     else:
-        displayer = display_util.FileDisplay(sys.stdout,
-                                             config.force_interactive)
-    zope.component.provideUtility(displayer)
+        displayer = display_util.FileDisplay(
+            sys.stdout, config.force_interactive)
+
+    try:
+        yield displayer
+    finally:
+        if devnull:
+            devnull.close()
 
 
 def main(cli_args=None):
@@ -1411,11 +1424,12 @@ def main(cli_args=None):
         if config.func != plugins_cmd:  # pylint: disable=comparison-with-callable
             raise
 
-    set_displayer(config)
-
     # Reporter
     report = reporter.Reporter(config)
     zope.component.provideUtility(report)
     util.atexit_register(report.print_messages)
 
-    return config.func(config, plugins)
+    with make_displayer(config) as displayer:
+        zope.component.provideUtility(displayer)
+
+        return config.func(config, plugins)

certbot/tests/log_test.py

@@ -28,7 +28,8 @@ class PreArgParseSetupTest(unittest.TestCase):
     @classmethod
     def _call(cls, *args, **kwargs):  # pylint: disable=unused-argument
         from certbot._internal.log import pre_arg_parse_setup
-        return pre_arg_parse_setup()
+        with mock.patch('builtins.open', mock.mock_open()):
+            return pre_arg_parse_setup()
 
     @mock.patch('certbot._internal.log.sys')
     @mock.patch('certbot._internal.log.pre_arg_parse_except_hook')

certbot/tests/plugins/webroot_test.py

@@ -141,7 +141,8 @@ class AuthenticatorTest(unittest.TestCase):
             f.write("thingimy")
         filesystem.chmod(self.path, 0o000)
         try:
-            open(permission_canary, "r")
+            with open(permission_canary, "r"):
+                pass
             print("Warning, running tests as root skips permissions tests...")
         except IOError:
             # ok, permissions work, test away...