Update pylint to v2.9.3 and fix the new issues it spots (#946)

In CI run against pylint 2.9.3 and fix occurrences of:
 - W0237 (arguments-renamed)
 - W0402 (deprecated-module)

The W0402 deprecated-module was about module `imp`:

    cloudinit/patcher.py:9: [W0402(deprecated-module), ]
        Uses of a deprecated module 'imp'

The imp module is deprecated and replaced by importlib, which according
to the documentation has no replacement for acquire_lock() and
release_lock(), which are the only reason why `imp` is imported.
    
Nothing about the code using this lock that actually requires it.
Let's remove the locking code and the import altogether.

Dropping the locking makes patcher.patch() an empty wrapper around
_patch_logging(). Rename _patch_logging() to patch_logging() and
call it directly instead. Drop patch().

12 files changed, 33 insertions, 42 deletions

diff --git a/cloudinit/cmd/main.py b/cloudinit/cmd/main.py
index 21213a4a..1de1de99 100644
--- a/cloudinit/cmd/main.py
+++ b/cloudinit/cmd/main.py
@@ -19,7 +19,7 @@ import time
 import traceback
 
 from cloudinit import patcher
-patcher.patch()  # noqa
+patcher.patch_logging()
 
 from cloudinit import log as logging
 from cloudinit import netinfo
diff --git a/cloudinit/distros/__init__.py b/cloudinit/distros/__init__.py
index 7bdf2197..40c4f2ac 100755
--- a/cloudinit/distros/__init__.py
+++ b/cloudinit/distros/__init__.py
@@ -147,7 +147,7 @@ class Distro(persistence.CloudInitPickleMixin, metaclass=abc.ABCMeta):
         return uses_systemd()
 
     @abc.abstractmethod
-    def package_command(self, cmd, args=None, pkgs=None):
+    def package_command(self, command, args=None, pkgs=None):
         raise NotImplementedError()
 
     @abc.abstractmethod
diff --git a/cloudinit/distros/alpine.py b/cloudinit/distros/alpine.py
index e4bed5a2..73b68baf 100644
--- a/cloudinit/distros/alpine.py
+++ b/cloudinit/distros/alpine.py
@@ -73,18 +73,18 @@ class Distro(distros.Distro):
         self.update_package_sources()
         self.package_command('add', pkgs=pkglist)
 
-    def _write_hostname(self, your_hostname, out_fn):
+    def _write_hostname(self, hostname, filename):
         conf = None
         try:
             # Try to update the previous one
             # so lets see if we can read it first.
-            conf = self._read_hostname_conf(out_fn)
+            conf = self._read_hostname_conf(filename)
         except IOError:
             pass
         if not conf:
             conf = HostnameConf('')
-        conf.set_hostname(your_hostname)
-        util.write_file(out_fn, str(conf), 0o644)
+        conf.set_hostname(hostname)
+        util.write_file(filename, str(conf), 0o644)
 
     def _read_system_hostname(self):
         sys_hostname = self._read_hostname(self.hostname_conf_fn)
diff --git a/cloudinit/distros/arch.py b/cloudinit/distros/arch.py
index c9acb11f..3c5bbb38 100644
--- a/cloudinit/distros/arch.py
+++ b/cloudinit/distros/arch.py
@@ -101,18 +101,18 @@ class Distro(distros.Distro):
             util.logexc(LOG, "Running interface command %s failed", cmd)
             return False
 
-    def _write_hostname(self, your_hostname, out_fn):
+    def _write_hostname(self, hostname, filename):
         conf = None
         try:
             # Try to update the previous one
             # so lets see if we can read it first.
-            conf = self._read_hostname_conf(out_fn)
+            conf = self._read_hostname_conf(filename)
         except IOError:
             pass
         if not conf:
             conf = HostnameConf('')
-        conf.set_hostname(your_hostname)
-        util.write_file(out_fn, str(conf), omode="w", mode=0o644)
+        conf.set_hostname(hostname)
+        util.write_file(filename, str(conf), omode="w", mode=0o644)
 
     def _read_system_hostname(self):
         sys_hostname = self._read_hostname(self.hostname_conf_fn)
diff --git a/cloudinit/distros/debian.py b/cloudinit/distros/debian.py
index 089e0c3e..f2b4dfc9 100644
--- a/cloudinit/distros/debian.py
+++ b/cloudinit/distros/debian.py
@@ -115,18 +115,18 @@ class Distro(distros.Distro):
         _maybe_remove_legacy_eth0()
         return super()._write_network_state(network_state)
 
-    def _write_hostname(self, your_hostname, out_fn):
+    def _write_hostname(self, hostname, filename):
         conf = None
         try:
             # Try to update the previous one
             # so lets see if we can read it first.
-            conf = self._read_hostname_conf(out_fn)
+            conf = self._read_hostname_conf(filename)
         except IOError:
             pass
         if not conf:
             conf = HostnameConf('')
-        conf.set_hostname(your_hostname)
-        util.write_file(out_fn, str(conf), 0o644)
+        conf.set_hostname(hostname)
+        util.write_file(filename, str(conf), 0o644)
 
     def _read_system_hostname(self):
         sys_hostname = self._read_hostname(self.hostname_conf_fn)
diff --git a/cloudinit/distros/gentoo.py b/cloudinit/distros/gentoo.py
index 68c03e7f..1be76dc8 100644
--- a/cloudinit/distros/gentoo.py
+++ b/cloudinit/distros/gentoo.py
@@ -149,12 +149,12 @@ class Distro(distros.Distro):
         else:
             return distros.Distro._bring_up_interfaces(self, device_names)
 
-    def _write_hostname(self, your_hostname, out_fn):
+    def _write_hostname(self, hostname, filename):
         conf = None
         try:
             # Try to update the previous one
             # so lets see if we can read it first.
-            conf = self._read_hostname_conf(out_fn)
+            conf = self._read_hostname_conf(filename)
         except IOError:
             pass
         if not conf:
@@ -163,8 +163,8 @@ class Distro(distros.Distro):
         # Many distro's format is the hostname by itself, and that is the
         # way HostnameConf works but gentoo expects it to be in
         #     hostname="the-actual-hostname"
-        conf.set_hostname('hostname="%s"' % your_hostname)
-        util.write_file(out_fn, str(conf), 0o644)
+        conf.set_hostname('hostname="%s"' % hostname)
+        util.write_file(filename, str(conf), 0o644)
 
     def _read_system_hostname(self):
         sys_hostname = self._read_hostname(self.hostname_conf_fn)
diff --git a/cloudinit/distros/opensuse.py b/cloudinit/distros/opensuse.py
index b4193ac2..2a7497cc 100644
--- a/cloudinit/distros/opensuse.py
+++ b/cloudinit/distros/opensuse.py
@@ -150,9 +150,9 @@ class Distro(distros.Distro):
             host_fn = self.hostname_conf_fn
         return (host_fn, self._read_hostname(host_fn))
 
-    def _write_hostname(self, hostname, out_fn):
-        if self.uses_systemd() and out_fn.endswith('/previous-hostname'):
-            util.write_file(out_fn, hostname)
+    def _write_hostname(self, hostname, filename):
+        if self.uses_systemd() and filename.endswith('/previous-hostname'):
+            util.write_file(filename, hostname)
         elif self.uses_systemd():
             subp.subp(['hostnamectl', 'set-hostname', str(hostname)])
         else:
@@ -160,13 +160,13 @@ class Distro(distros.Distro):
             try:
                 # Try to update the previous one
                 # so lets see if we can read it first.
-                conf = self._read_hostname_conf(out_fn)
+                conf = self._read_hostname_conf(filename)
             except IOError:
                 pass
             if not conf:
                 conf = HostnameConf('')
             conf.set_hostname(hostname)
-            util.write_file(out_fn, str(conf), 0o644)
+            util.write_file(filename, str(conf), 0o644)
 
     @property
     def preferred_ntp_clients(self):
diff --git a/cloudinit/distros/photon.py b/cloudinit/distros/photon.py
index 0ced7b5f..3ef5dd40 100644
--- a/cloudinit/distros/photon.py
+++ b/cloudinit/distros/photon.py
@@ -83,19 +83,19 @@ class Distro(distros.Distro):
         ret, _out, _err = self.exec_cmd(cmd)
         return ret
 
-    def _write_hostname(self, hostname, out_fn):
+    def _write_hostname(self, hostname, filename):
         conf = None
         try:
             # Try to update the previous one
             # Let's see if we can read it first.
-            conf = HostnameConf(util.load_file(out_fn))
+            conf = HostnameConf(util.load_file(filename))
             conf.parse()
         except IOError:
             pass
         if not conf:
             conf = HostnameConf('')
         conf.set_hostname(hostname)
-        util.write_file(out_fn, str(conf), mode=0o644)
+        util.write_file(filename, str(conf), mode=0o644)
 
     def _read_system_hostname(self):
         sys_hostname = self._read_hostname(self.hostname_conf_fn)
diff --git a/cloudinit/distros/rhel.py b/cloudinit/distros/rhel.py
index be5b3d24..c9ee2747 100644
--- a/cloudinit/distros/rhel.py
+++ b/cloudinit/distros/rhel.py
@@ -78,18 +78,18 @@ class Distro(distros.Distro):
         }
         rhel_util.update_sysconfig_file(out_fn, locale_cfg)
 
-    def _write_hostname(self, hostname, out_fn):
+    def _write_hostname(self, hostname, filename):
         # systemd will never update previous-hostname for us, so
         # we need to do it ourselves
-        if self.uses_systemd() and out_fn.endswith('/previous-hostname'):
-            util.write_file(out_fn, hostname)
+        if self.uses_systemd() and filename.endswith('/previous-hostname'):
+            util.write_file(filename, hostname)
         elif self.uses_systemd():
             subp.subp(['hostnamectl', 'set-hostname', str(hostname)])
         else:
             host_cfg = {
                 'HOSTNAME': hostname,
             }
-            rhel_util.update_sysconfig_file(out_fn, host_cfg)
+            rhel_util.update_sysconfig_file(filename, host_cfg)
 
     def _read_system_hostname(self):
         if self.uses_systemd():
diff --git a/cloudinit/patcher.py b/cloudinit/patcher.py
index 2df9441a..186d8ad8 100644
--- a/cloudinit/patcher.py
+++ b/cloudinit/patcher.py
@@ -6,7 +6,6 @@
 #
 # This file is part of cloud-init. See LICENSE file for license information.
 
-import imp
 import logging
 import sys
 
@@ -20,7 +19,7 @@ class QuietStreamHandler(logging.StreamHandler):
         pass
 
 
-def _patch_logging():
+def patch_logging():
     # Replace 'handleError' with one that will be more
     # tolerant of errors in that it can avoid
     # re-notifying on exceptions and when errors
@@ -37,12 +36,4 @@ def _patch_logging():
             pass
     setattr(logging.Handler, 'handleError', handleError)
 
-
-def patch():
-    imp.acquire_lock()
-    try:
-        _patch_logging()
-    finally:
-        imp.release_lock()
-
 # vi: ts=4 expandtab
diff --git a/tests/unittests/test_distros/test_create_users.py b/tests/unittests/test_distros/test_create_users.py
index 94ab052d..021866b7 100644
--- a/tests/unittests/test_distros/test_create_users.py
+++ b/tests/unittests/test_distros/test_create_users.py
@@ -23,7 +23,7 @@ class MyBaseDistro(distros.Distro):
     def _write_network(self, settings):
         raise NotImplementedError()
 
-    def package_command(self, cmd, args=None, pkgs=None):
+    def package_command(self, command, args=None, pkgs=None):
         raise NotImplementedError()
 
     def update_package_sources(self):
diff --git a/tox.ini b/tox.ini
index f21e1186..27c16ef3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -23,7 +23,7 @@ setenv =
 basepython = python3
 deps =
     # requirements
-    pylint==2.6.0
+    pylint==2.9.3
     # test-requirements because unit tests are now present in cloudinit tree
     -r{toxinidir}/test-requirements.txt
     -r{toxinidir}/integration-requirements.txt