Merge ~smoser/cloud-init:cleanup/pylint-respect-W0612-unused-variable into cloud-init:master

[Scott Moser]

pylint: pay attention to unused variable warnings.

This enables warnings produced by pylint for unused variables (W0612),
and fixes the existing errors.

see commit message

[Server Team CI bot (server-team-bot)]

FAILED: Continuous integration, rev:2a46897cce9284be00a722d7b2b30a8a8f28a6e9
https://jenkins.ubuntu.com/server/job/cloud-init-ci/1019/
Executed test runs:
    SUCCESS: Checkout
    FAILED: Unit & Style Tests

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/1019/rebuild

review: Needs Fixing (continuous-integration)

[Ryan Harper (raharper)]

Fix your commit message, you're paying attention to:

# W0612(unused-variable)

Not

# W0621(redefined-outer-name)

[Ryan Harper (raharper)]

tox -e pylint finds a few more for me.

[Server Team CI bot (server-team-bot)]

FAILED: Continuous integration, rev:41e3e47422f4c4bbb4fcbbd93ebf5b03b56f979d
https://jenkins.ubuntu.com/server/job/cloud-init-ci/1020/
Executed test runs:
    SUCCESS: Checkout
    FAILED: Unit & Style Tests

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/1020/rebuild

review: Needs Fixing (continuous-integration)

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:3ddd3a322945a9bff8d1906fe2a268c70f851b92
https://jenkins.ubuntu.com/server/job/cloud-init-ci/1021/
Executed test runs:
    SUCCESS: Checkout
    SUCCESS: Unit & Style Tests
    SUCCESS: Ubuntu LTS: Build
    SUCCESS: Ubuntu LTS: Integration
    SUCCESS: MAAS Compatability Testing
    IN_PROGRESS: Declarative: Post Actions

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/1021/rebuild

review: Approve (continuous-integration)

[Ryan Harper (raharper)]

Looks good.

review: Approve

[Chad Smith (chad.smith)]

An upstream commit landed for this bug.

To view that commit see the following URL:
https://git.launchpad.net/cloud-init/commit/?id=1081962e

diff --git a/.pylintrc b/.pylintrc
index 0bdfa59..3bfa0c8 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -28,7 +28,7 @@ jobs=4
 # W0703(broad-except)
 # W1401(anomalous-backslash-in-string)
 
-disable=C, F, I, R, W0105, W0107, W0201, W0212, W0221, W0222, W0223, W0231, W0311, W0511, W0602, W0603, W0611, W0612, W0613, W0621, W0622, W0631, W0703, W1401
+disable=C, F, I, R, W0105, W0107, W0201, W0212, W0221, W0222, W0223, W0231, W0311, W0511, W0602, W0603, W0611, W0613, W0621, W0622, W0631, W0703, W1401
 
 
 [REPORTS]
diff --git a/cloudinit/analyze/dump.py b/cloudinit/analyze/dump.py
index b071aa1..1f3060d 100644
--- a/cloudinit/analyze/dump.py
+++ b/cloudinit/analyze/dump.py
@@ -112,7 +112,7 @@ def parse_ci_logline(line):
             return None
         event_description = stage_to_description[event_name]
     else:
-        (pymodloglvl, event_type, event_name) = eventstr.split()[0:3]
+        (_pymodloglvl, event_type, event_name) = eventstr.split()[0:3]
         event_description = eventstr.split(event_name)[1].strip()
 
     event = {
diff --git a/cloudinit/cmd/tests/test_main.py b/cloudinit/cmd/tests/test_main.py
index dbe421c..e2c54ae 100644
--- a/cloudinit/cmd/tests/test_main.py
+++ b/cloudinit/cmd/tests/test_main.py
@@ -56,7 +56,7 @@ class TestMain(FilesystemMockingTestCase):
         cmdargs = myargs(
             debug=False, files=None, force=False, local=False, reporter=None,
             subcommand='init')
-        (item1, item2) = wrap_and_call(
+        (_item1, item2) = wrap_and_call(
             'cloudinit.cmd.main',
             {'util.close_stdin': True,
              'netinfo.debug_info': 'my net debug info',
@@ -85,7 +85,7 @@ class TestMain(FilesystemMockingTestCase):
         cmdargs = myargs(
             debug=False, files=None, force=False, local=False, reporter=None,
             subcommand='init')
-        (item1, item2) = wrap_and_call(
+        (_item1, item2) = wrap_and_call(
             'cloudinit.cmd.main',
             {'util.close_stdin': True,
              'netinfo.debug_info': 'my net debug info',
@@ -133,7 +133,7 @@ class TestMain(FilesystemMockingTestCase):
             self.assertEqual(main.LOG, log)
             self.assertIsNone(args)
 
-        (item1, item2) = wrap_and_call(
+        (_item1, item2) = wrap_and_call(
             'cloudinit.cmd.main',
             {'util.close_stdin': True,
              'netinfo.debug_info': 'my net debug info',
diff --git a/cloudinit/config/cc_apt_configure.py b/cloudinit/config/cc_apt_configure.py
index 5b9cbca..e4cc993 100644
--- a/cloudinit/config/cc_apt_configure.py
+++ b/cloudinit/config/cc_apt_configure.py
@@ -378,7 +378,7 @@ def apply_debconf_selections(cfg, target=None):
 
     # get a complete list of packages listed in input
     pkgs_cfgd = set()
-    for key, content in selsets.items():
+    for _key, content in selsets.items():
         for line in content.splitlines():
             if line.startswith("#"):
                 continue
diff --git a/cloudinit/config/cc_emit_upstart.py b/cloudinit/config/cc_emit_upstart.py
index 69dc2d5..eb9fbe6 100644
--- a/cloudinit/config/cc_emit_upstart.py
+++ b/cloudinit/config/cc_emit_upstart.py
@@ -43,7 +43,7 @@ def is_upstart_system():
         del myenv['UPSTART_SESSION']
     check_cmd = ['initctl', 'version']
     try:
-        (out, err) = util.subp(check_cmd, env=myenv)
+        (out, _err) = util.subp(check_cmd, env=myenv)
         return 'upstart' in out
     except util.ProcessExecutionError as e:
         LOG.debug("'%s' returned '%s', not using upstart",
diff --git a/cloudinit/config/cc_resizefs.py b/cloudinit/config/cc_resizefs.py
index 013e69b..82f29e1 100644
--- a/cloudinit/config/cc_resizefs.py
+++ b/cloudinit/config/cc_resizefs.py
@@ -89,13 +89,11 @@ def _resize_zfs(mount_point, devpth):
 
 
 def _get_dumpfs_output(mount_point):
-    dumpfs_res, err = util.subp(['dumpfs', '-m', mount_point])
-    return dumpfs_res
+    return util.subp(['dumpfs', '-m', mount_point])[0]
 
 
 def _get_gpart_output(part):
-    gpart_res, err = util.subp(['gpart', 'show', part])
-    return gpart_res
+    return util.subp(['gpart', 'show', part])[0]
 
 
 def _can_skip_resize_ufs(mount_point, devpth):
@@ -113,7 +111,7 @@ def _can_skip_resize_ufs(mount_point, devpth):
         if not line.startswith('#'):
             newfs_cmd = shlex.split(line)
             opt_value = 'O:Ua:s:b:d:e:f:g:h:i:jk:m:o:'
-            optlist, args = getopt.getopt(newfs_cmd[1:], opt_value)
+            optlist, _args = getopt.getopt(newfs_cmd[1:], opt_value)
             for o, a in optlist:
                 if o == "-s":
                     cur_fs_sz = int(a)
diff --git a/cloudinit/config/cc_rh_subscription.py b/cloudinit/config/cc_rh_subscription.py
index 530808c..1c67943 100644
--- a/cloudinit/config/cc_rh_subscription.py
+++ b/cloudinit/config/cc_rh_subscription.py
@@ -209,8 +209,7 @@ class SubscriptionManager(object):
                 cmd.append("--serverurl={0}".format(self.server_hostname))
 
             try:
-                return_out, return_err = self._sub_man_cli(cmd,
-                                                           logstring_val=True)
+                return_out = self._sub_man_cli(cmd, logstring_val=True)[0]
             except util.ProcessExecutionError as e:
                 if e.stdout == "":
                     self.log_warn("Registration failed due "
@@ -233,8 +232,7 @@ class SubscriptionManager(object):
 
             # Attempting to register the system only
             try:
-                return_out, return_err = self._sub_man_cli(cmd,
-                                                           logstring_val=True)
+                return_out = self._sub_man_cli(cmd, logstring_val=True)[0]
             except util.ProcessExecutionError as e:
                 if e.stdout == "":
                     self.log_warn("Registration failed due "
@@ -257,7 +255,7 @@ class SubscriptionManager(object):
                .format(self.servicelevel)]
 
         try:
-            return_out, return_err = self._sub_man_cli(cmd)
+            return_out = self._sub_man_cli(cmd)[0]
         except util.ProcessExecutionError as e:
             if e.stdout.rstrip() != '':
                 for line in e.stdout.split("\n"):
@@ -275,7 +273,7 @@ class SubscriptionManager(object):
     def _set_auto_attach(self):
         cmd = ['attach', '--auto']
         try:
-            return_out, return_err = self._sub_man_cli(cmd)
+            return_out = self._sub_man_cli(cmd)[0]
         except util.ProcessExecutionError as e:
             self.log_warn("Auto-attach failed with: {0}".format(e))
             return False
@@ -294,12 +292,12 @@ class SubscriptionManager(object):
 
         # Get all available pools
         cmd = ['list', '--available', '--pool-only']
-        results, errors = self._sub_man_cli(cmd)
+        results = self._sub_man_cli(cmd)[0]
         available = (results.rstrip()).split("\n")
 
         # Get all consumed pools
         cmd = ['list', '--consumed', '--pool-only']
-        results, errors = self._sub_man_cli(cmd)
+        results = self._sub_man_cli(cmd)[0]
         consumed = (results.rstrip()).split("\n")
 
         return available, consumed
@@ -311,14 +309,14 @@ class SubscriptionManager(object):
         '''
 
         cmd = ['repos', '--list-enabled']
-        return_out, return_err = self._sub_man_cli(cmd)
+        return_out = self._sub_man_cli(cmd)[0]
         active_repos = []
         for repo in return_out.split("\n"):
             if "Repo ID:" in repo:
                 active_repos.append((repo.split(':')[1]).strip())
 
         cmd = ['repos', '--list-disabled']
-        return_out, return_err = self._sub_man_cli(cmd)
+        return_out = self._sub_man_cli(cmd)[0]
 
         inactive_repos = []
         for repo in return_out.split("\n"):
diff --git a/cloudinit/config/cc_snap.py b/cloudinit/config/cc_snap.py
index 34a53fd..202044c 100644
--- a/cloudinit/config/cc_snap.py
+++ b/cloudinit/config/cc_snap.py
@@ -204,12 +204,12 @@ def maybe_install_squashfuse(cloud):
         return
     try:
         cloud.distro.update_package_sources()
-    except Exception as e:
+    except Exception:
         util.logexc(LOG, "Package update failed")
         raise
     try:
         cloud.distro.install_packages(['squashfuse'])
-    except Exception as e:
+    except Exception:
         util.logexc(LOG, "Failed to install squashfuse")
         raise
 
diff --git a/cloudinit/config/cc_snappy.py b/cloudinit/config/cc_snappy.py
index bab80bb..15bee2d 100644
--- a/cloudinit/config/cc_snappy.py
+++ b/cloudinit/config/cc_snappy.py
@@ -213,7 +213,7 @@ def render_snap_op(op, name, path=None, cfgfile=None, config=None):
 
 def read_installed_packages():
     ret = []
-    for (name, date, version, dev) in read_pkg_data():
+    for (name, _date, _version, dev) in read_pkg_data():
         if dev:
             ret.append(NAMESPACE_DELIM.join([name, dev]))
         else:
@@ -222,7 +222,7 @@ def read_installed_packages():
 
 
 def read_pkg_data():
-    out, err = util.subp([SNAPPY_CMD, "list"])
+    out, _err = util.subp([SNAPPY_CMD, "list"])
     pkg_data = []
     for line in out.splitlines()[1:]:
         toks = line.split(sep=None, maxsplit=3)
diff --git a/cloudinit/config/cc_ubuntu_advantage.py b/cloudinit/config/cc_ubuntu_advantage.py
index 16b1868..903704f 100644
--- a/cloudinit/config/cc_ubuntu_advantage.py
+++ b/cloudinit/config/cc_ubuntu_advantage.py
@@ -149,12 +149,12 @@ def maybe_install_ua_tools(cloud):
         return
     try:
         cloud.distro.update_package_sources()
-    except Exception as e:
+    except Exception:
         util.logexc(LOG, "Package update failed")
         raise
     try:
         cloud.distro.install_packages(['ubuntu-advantage-tools'])
-    except Exception as e:
+    except Exception:
         util.logexc(LOG, "Failed to install ubuntu-advantage-tools")
         raise
 
diff --git a/cloudinit/config/schema.py b/cloudinit/config/schema.py
index ca7d0d5..76826e0 100644
--- a/cloudinit/config/schema.py
+++ b/cloudinit/config/schema.py
@@ -297,8 +297,8 @@ def get_schema():
 
     configs_dir = os.path.dirname(os.path.abspath(__file__))
     potential_handlers = find_modules(configs_dir)
-    for (fname, mod_name) in potential_handlers.items():
-        mod_locs, looked_locs = importer.find_module(
+    for (_fname, mod_name) in potential_handlers.items():
+        mod_locs, _looked_locs = importer.find_module(
             mod_name, ['cloudinit.config'], ['schema'])
         if mod_locs:
             mod = importer.import_module(mod_locs[0])
diff --git a/cloudinit/distros/freebsd.py b/cloudinit/distros/freebsd.py
index 754d3df..03ee091 100644
--- a/cloudinit/distros/freebsd.py
+++ b/cloudinit/distros/freebsd.py
@@ -113,7 +113,7 @@ class Distro(distros.Distro):
         n = re.search('\d+$', dev)
         index = n.group(0)
 
-        (out, err) = util.subp(['ifconfig', '-a'])
+        (out, _err) = util.subp(['ifconfig', '-a'])
         ifconfigoutput = [x for x in (out.strip()).splitlines()
                           if len(x.split()) > 0]
         bsddev = 'NOT_FOUND'
diff --git a/cloudinit/distros/ubuntu.py b/cloudinit/distros/ubuntu.py
index fdc1f62..6815410 100644
--- a/cloudinit/distros/ubuntu.py
+++ b/cloudinit/distros/ubuntu.py
@@ -25,7 +25,7 @@ class Distro(debian.Distro):
     def preferred_ntp_clients(self):
         """The preferred ntp client is dependent on the version."""
         if not self._preferred_ntp_clients:
-            (name, version, codename) = util.system_info()['dist']
+            (_name, _version, codename) = util.system_info()['dist']
             # Xenial cloud-init only installed ntp, UbuntuCore has timesyncd.
             if codename == "xenial" and not util.system_is_snappy():
                 self._preferred_ntp_clients = ['ntp']
diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index f69c0ef..8005454 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -295,7 +295,7 @@ def apply_network_config_names(netcfg, strict_present=True, strict_busy=True):
 
     def _version_2(netcfg):
         renames = []
-        for key, ent in netcfg.get('ethernets', {}).items():
+        for ent in netcfg.get('ethernets', {}).values():
             # only rename if configured to do so
             name = ent.get('set-name')
             if not name:
diff --git a/cloudinit/net/cmdline.py b/cloudinit/net/cmdline.py
index 9e9fe0f..f89a0f7 100755
--- a/cloudinit/net/cmdline.py
+++ b/cloudinit/net/cmdline.py
@@ -65,7 +65,7 @@ def _klibc_to_config_entry(content, mac_addrs=None):
         iface['mac_address'] = mac_addrs[name]
 
     # Handle both IPv4 and IPv6 values
-    for v, pre in (('ipv4', 'IPV4'), ('ipv6', 'IPV6')):
+    for pre in ('IPV4', 'IPV6'):
         # if no IPV4ADDR or IPV6ADDR, then go on.
         if pre + "ADDR" not in data:
             continue
diff --git a/cloudinit/net/dhcp.py b/cloudinit/net/dhcp.py
index 087c0c0..12cf509 100644
--- a/cloudinit/net/dhcp.py
+++ b/cloudinit/net/dhcp.py
@@ -216,7 +216,7 @@ def networkd_get_option_from_leases(keyname, leases_d=None):
     if leases_d is None:
         leases_d = NETWORKD_LEASES_DIR
     leases = networkd_load_leases(leases_d=leases_d)
-    for ifindex, data in sorted(leases.items()):
+    for _ifindex, data in sorted(leases.items()):
         if data.get(keyname):
             return data[keyname]
     return None
diff --git a/cloudinit/net/sysconfig.py b/cloudinit/net/sysconfig.py
index 39d89c4..7a7f509 100644
--- a/cloudinit/net/sysconfig.py
+++ b/cloudinit/net/sysconfig.py
@@ -364,7 +364,7 @@ class Renderer(renderer.Renderer):
 
     @classmethod
     def _render_subnet_routes(cls, iface_cfg, route_cfg, subnets):
-        for i, subnet in enumerate(subnets, start=len(iface_cfg.children)):
+        for _, subnet in enumerate(subnets, start=len(iface_cfg.children)):
             for route in subnet.get('routes', []):
                 is_ipv6 = subnet.get('ipv6') or is_ipv6_addr(route['gateway'])
 
diff --git a/cloudinit/reporting/events.py b/cloudinit/reporting/events.py
index 4f62d2f..e5dfab3 100644
--- a/cloudinit/reporting/events.py
+++ b/cloudinit/reporting/events.py
@@ -192,7 +192,7 @@ class ReportEventStack(object):
 
     def _childrens_finish_info(self):
         for cand_result in (status.FAIL, status.WARN):
-            for name, (value, msg) in self.children.items():
+            for _name, (value, _msg) in self.children.items():
                 if value == cand_result:
                     return (value, self.message)
         return (self.result, self.message)
diff --git a/cloudinit/sources/DataSourceAliYun.py b/cloudinit/sources/DataSourceAliYun.py
index 22279d0..858e082 100644
--- a/cloudinit/sources/DataSourceAliYun.py
+++ b/cloudinit/sources/DataSourceAliYun.py
@@ -45,7 +45,7 @@ def _is_aliyun():
 
 def parse_public_keys(public_keys):
     keys = []
-    for key_id, key_body in public_keys.items():
+    for _key_id, key_body in public_keys.items():
         if isinstance(key_body, str):
             keys.append(key_body.strip())
         elif isinstance(key_body, list):
diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index 0ee622e..a71197a 100644
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -107,31 +107,24 @@ def find_dev_from_busdev(camcontrol_out, busdev):
     return None
 
 
-def get_dev_storvsc_sysctl():
+def execute_or_debug(cmd, fail_ret=None):
     try:
-        sysctl_out, err = util.subp(['sysctl', 'dev.storvsc'])
+        return util.subp(cmd)[0]
     except util.ProcessExecutionError:
-        LOG.debug("Fail to execute sysctl dev.storvsc")
-        sysctl_out = ""
-    return sysctl_out
+        LOG.debug("Failed to execute: %s", ' '.join(cmd))
+        return fail_ret
+
+
+def get_dev_storvsc_sysctl():
+    return execute_or_debug(["sysctl", "dev.storvsc"], fail_ret="")
 
 
 def get_camcontrol_dev_bus():
-    try:
-        camcontrol_b_out, err = util.subp(['camcontrol', 'devlist', '-b'])
-    except util.ProcessExecutionError:
-        LOG.debug("Fail to execute camcontrol devlist -b")
-        return None
-    return camcontrol_b_out
+    return execute_or_debug(['camcontrol', 'devlist', '-b'])
 
 
 def get_camcontrol_dev():
-    try:
-        camcontrol_out, err = util.subp(['camcontrol', 'devlist'])
-    except util.ProcessExecutionError:
-        LOG.debug("Fail to execute camcontrol devlist")
-        return None
-    return camcontrol_out
+    return execute_or_debug(['camcontrol', 'devlist'])
 
 
 def get_resource_disk_on_freebsd(port_id):
@@ -474,7 +467,7 @@ class DataSourceAzure(sources.DataSource):
            before we go into our polling loop."""
         try:
             get_metadata_from_fabric(None, lease['unknown-245'])
-        except Exception as exc:
+        except Exception:
             LOG.warning(
                 "Error communicating with Azure fabric; You may experience."
                 "connectivity issues.", exc_info=True)
@@ -492,7 +485,7 @@ class DataSourceAzure(sources.DataSource):
         jump back into the polling loop in order to retrieve the ovf_env."""
         if not ret:
             return False
-        (md, self.userdata_raw, cfg, files) = ret
+        (_md, self.userdata_raw, cfg, _files) = ret
         path = REPROVISION_MARKER_FILE
         if (cfg.get('PreprovisionedVm') is True or
                 os.path.isfile(path)):
@@ -528,7 +521,7 @@ class DataSourceAzure(sources.DataSource):
                   self.ds_cfg['agent_command'])
         try:
             fabric_data = metadata_func()
-        except Exception as exc:
+        except Exception:
             LOG.warning(
                 "Error communicating with Azure fabric; You may experience."
                 "connectivity issues.", exc_info=True)
diff --git a/cloudinit/sources/DataSourceMAAS.py b/cloudinit/sources/DataSourceMAAS.py
index 6ac8863..aa56add 100644
--- a/cloudinit/sources/DataSourceMAAS.py
+++ b/cloudinit/sources/DataSourceMAAS.py
@@ -204,7 +204,7 @@ def read_maas_seed_url(seed_url, read_file_or_url=None, timeout=None,
         seed_url = seed_url[:-1]
 
     md = {}
-    for path, dictname, binary, optional in DS_FIELDS:
+    for path, _dictname, binary, optional in DS_FIELDS:
         if version is None:
             url = "%s/%s" % (seed_url, path)
         else:
diff --git a/cloudinit/sources/DataSourceOVF.py b/cloudinit/sources/DataSourceOVF.py
index dc914a7..178ccb0 100644
--- a/cloudinit/sources/DataSourceOVF.py
+++ b/cloudinit/sources/DataSourceOVF.py
@@ -556,7 +556,7 @@ def search_file(dirpath, filename):
     if not dirpath or not filename:
         return None
 
-    for root, dirs, files in os.walk(dirpath):
+    for root, _dirs, files in os.walk(dirpath):
         if filename in files:
             return os.path.join(root, filename)
 
diff --git a/cloudinit/sources/DataSourceOpenStack.py b/cloudinit/sources/DataSourceOpenStack.py
index e55a763..fb166ae 100644
--- a/cloudinit/sources/DataSourceOpenStack.py
+++ b/cloudinit/sources/DataSourceOpenStack.py
@@ -86,7 +86,7 @@ class DataSourceOpenStack(openstack.SourceMixin, sources.DataSource):
             md_urls.append(md_url)
             url2base[md_url] = url
 
-        (max_wait, timeout, retries) = self._get_url_settings()
+        (max_wait, timeout, _retries) = self._get_url_settings()
         start_time = time.time()
         avail_url = url_helper.wait_for_url(urls=md_urls, max_wait=max_wait,
                                             timeout=timeout)
@@ -106,7 +106,7 @@ class DataSourceOpenStack(openstack.SourceMixin, sources.DataSource):
         except IOError:
             return False
 
-        (max_wait, timeout, retries) = self._get_url_settings()
+        (_max_wait, timeout, retries) = self._get_url_settings()
 
         try:
             results = util.log_time(LOG.debug,
diff --git a/cloudinit/sources/helpers/digitalocean.py b/cloudinit/sources/helpers/digitalocean.py
index 693f8d5..0e7ccca 100644
--- a/cloudinit/sources/helpers/digitalocean.py
+++ b/cloudinit/sources/helpers/digitalocean.py
@@ -41,10 +41,9 @@ def assign_ipv4_link_local(nic=None):
                            "address")
 
     try:
-        (result, _err) = util.subp(ip_addr_cmd)
+        util.subp(ip_addr_cmd)
         LOG.debug("assigned ip4LL address '%s' to '%s'", addr, nic)
-
-        (result, _err) = util.subp(ip_link_cmd)
+        util.subp(ip_link_cmd)
         LOG.debug("brought device '%s' up", nic)
     except Exception:
         util.logexc(LOG, "ip4LL address assignment of '%s' to '%s' failed."
@@ -75,7 +74,7 @@ def del_ipv4_link_local(nic=None):
     ip_addr_cmd = ['ip', 'addr', 'flush', 'dev', nic]
 
     try:
-        (result, _err) = util.subp(ip_addr_cmd)
+        util.subp(ip_addr_cmd)
         LOG.debug("removed ip4LL addresses from %s", nic)
 
     except Exception as e:
diff --git a/cloudinit/sources/helpers/openstack.py b/cloudinit/sources/helpers/openstack.py
index 26f3168..a4cf066 100644
--- a/cloudinit/sources/helpers/openstack.py
+++ b/cloudinit/sources/helpers/openstack.py
@@ -638,7 +638,7 @@ def convert_net_json(network_json=None, known_macs=None):
             known_macs = net.get_interfaces_by_mac()
 
         # go through and fill out the link_id_info with names
-        for link_id, info in link_id_info.items():
+        for _link_id, info in link_id_info.items():
             if info.get('name'):
                 continue
             if info.get('mac') in known_macs:
diff --git a/cloudinit/sources/helpers/vmware/imc/config_nic.py b/cloudinit/sources/helpers/vmware/imc/config_nic.py
index 2d8900e..3ef8c62 100644
--- a/cloudinit/sources/helpers/vmware/imc/config_nic.py
+++ b/cloudinit/sources/helpers/vmware/imc/config_nic.py
@@ -73,7 +73,7 @@ class NicConfigurator(object):
         The mac address(es) are in the lower case
         """
         cmd = ['ip', 'addr', 'show']
-        (output, err) = util.subp(cmd)
+        output, _err = util.subp(cmd)
         sections = re.split(r'\n\d+: ', '\n' + output)[1:]
 
         macPat = r'link/ether (([0-9A-Fa-f]{2}[:]){5}([0-9A-Fa-f]{2}))'
diff --git a/cloudinit/sources/helpers/vmware/imc/config_passwd.py b/cloudinit/sources/helpers/vmware/imc/config_passwd.py
index 75cfbaa..8c91fa4 100644
--- a/cloudinit/sources/helpers/vmware/imc/config_passwd.py
+++ b/cloudinit/sources/helpers/vmware/imc/config_passwd.py
@@ -56,10 +56,10 @@ class PasswordConfigurator(object):
         LOG.info('Expiring password.')
         for user in uidUserList:
             try:
-                out, err = util.subp(['passwd', '--expire', user])
+                util.subp(['passwd', '--expire', user])
             except util.ProcessExecutionError as e:
                 if os.path.exists('/usr/bin/chage'):
-                    out, e = util.subp(['chage', '-d', '0', user])
+                    util.subp(['chage', '-d', '0', user])
                 else:
                     LOG.warning('Failed to expire password for %s with error: '
                                 '%s', user, e)
diff --git a/cloudinit/sources/helpers/vmware/imc/guestcust_util.py b/cloudinit/sources/helpers/vmware/imc/guestcust_util.py
index 4407525..a590f32 100644
--- a/cloudinit/sources/helpers/vmware/imc/guestcust_util.py
+++ b/cloudinit/sources/helpers/vmware/imc/guestcust_util.py
@@ -91,7 +91,7 @@ def enable_nics(nics):
 
     for attempt in range(0, enableNicsWaitRetries):
         logger.debug("Trying to connect interfaces, attempt %d", attempt)
-        (out, err) = set_customization_status(
+        (out, _err) = set_customization_status(
             GuestCustStateEnum.GUESTCUST_STATE_RUNNING,
             GuestCustEventEnum.GUESTCUST_EVENT_ENABLE_NICS,
             nics)
@@ -104,7 +104,7 @@ def enable_nics(nics):
             return
 
         for count in range(0, enableNicsWaitCount):
-            (out, err) = set_customization_status(
+            (out, _err) = set_customization_status(
                 GuestCustStateEnum.GUESTCUST_STATE_RUNNING,
                 GuestCustEventEnum.GUESTCUST_EVENT_QUERY_NICS,
                 nics)
diff --git a/cloudinit/sources/tests/test_init.py b/cloudinit/sources/tests/test_init.py
index e7fda22..452e921 100644
--- a/cloudinit/sources/tests/test_init.py
+++ b/cloudinit/sources/tests/test_init.py
@@ -278,7 +278,7 @@ class TestDataSource(CiTestCase):
         base_args = get_args(DataSource.get_hostname)  # pylint: disable=W1505
         # Import all DataSource subclasses so we can inspect them.
         modules = util.find_modules(os.path.dirname(os.path.dirname(__file__)))
-        for loc, name in modules.items():
+        for _loc, name in modules.items():
             mod_locs, _ = importer.find_module(name, ['cloudinit.sources'], [])
             if mod_locs:
                 importer.import_module(mod_locs[0])
diff --git a/cloudinit/templater.py b/cloudinit/templater.py
index 9a087e1..7e7acb8 100644
--- a/cloudinit/templater.py
+++ b/cloudinit/templater.py
@@ -147,7 +147,7 @@ def render_string(content, params):
     Warning: py2 str with non-ascii chars will cause UnicodeDecodeError."""
     if not params:
         params = {}
-    template_type, renderer, content = detect_template(content)
+    _template_type, renderer, content = detect_template(content)
     return renderer(content, params)
 
 # vi: ts=4 expandtab
diff --git a/cloudinit/tests/helpers.py b/cloudinit/tests/helpers.py
index 999b1d7..996888e 100644
--- a/cloudinit/tests/helpers.py
+++ b/cloudinit/tests/helpers.py
@@ -358,7 +358,7 @@ def dir2dict(startdir, prefix=None):
     flist = {}
     if prefix is None:
         prefix = startdir
-    for root, dirs, files in os.walk(startdir):
+    for root, _dirs, files in os.walk(startdir):
         for fname in files:
             fpath = os.path.join(root, fname)
             key = fpath[len(prefix):]
diff --git a/cloudinit/tests/test_util.py b/cloudinit/tests/test_util.py
index 3f37dbb..76eed07 100644
--- a/cloudinit/tests/test_util.py
+++ b/cloudinit/tests/test_util.py
@@ -135,7 +135,7 @@ class TestGetHostnameFqdn(CiTestCase):
     def test_get_hostname_fqdn_from_passes_metadata_only_to_cloud(self):
         """Calls to cloud.get_hostname pass the metadata_only parameter."""
         mycloud = FakeCloud('cloudhost', 'cloudhost.mycloud.com')
-        hostname, fqdn = util.get_hostname_fqdn(
+        _hn, _fqdn = util.get_hostname_fqdn(
             cfg={}, cloud=mycloud, metadata_only=True)
         self.assertEqual(
             [{'fqdn': True, 'metadata_only': True},
diff --git a/cloudinit/url_helper.py b/cloudinit/url_helper.py
index 03a573a..1de07b1 100644
--- a/cloudinit/url_helper.py
+++ b/cloudinit/url_helper.py
@@ -519,7 +519,7 @@ def oauth_headers(url, consumer_key, token_key, token_secret, consumer_secret,
         resource_owner_secret=token_secret,
         signature_method=oauth1.SIGNATURE_PLAINTEXT,
         timestamp=timestamp)
-    uri, signed_headers, body = client.sign(url)
+    _uri, signed_headers, _body = client.sign(url)
     return signed_headers
 
 # vi: ts=4 expandtab
diff --git a/cloudinit/util.py b/cloudinit/util.py
index acdc0d8..d8b5e09 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -2214,7 +2214,7 @@ def parse_mtab(path):
 def find_freebsd_part(label_part):
     if label_part.startswith("/dev/label/"):
         target_label = label_part[5:]
-        (label_part, err) = subp(['glabel', 'status', '-s'])
+        (label_part, _err) = subp(['glabel', 'status', '-s'])
         for labels in label_part.split("\n"):
             items = labels.split()
             if len(items) > 0 and items[0].startswith(target_label):
diff --git a/tests/cloud_tests/bddeb.py b/tests/cloud_tests/bddeb.py
index b9cfcfa..f04d0cd 100644
--- a/tests/cloud_tests/bddeb.py
+++ b/tests/cloud_tests/bddeb.py
@@ -113,7 +113,7 @@ def bddeb(args):
     @return_value: fail count
     """
     LOG.info('preparing to build cloud-init deb')
-    (res, failed) = run_stage('build deb', [partial(setup_build, args)])
+    _res, failed = run_stage('build deb', [partial(setup_build, args)])
     return failed
 
 # vi: ts=4 expandtab
diff --git a/tests/cloud_tests/collect.py b/tests/cloud_tests/collect.py
index d4f9135..1ba7285 100644
--- a/tests/cloud_tests/collect.py
+++ b/tests/cloud_tests/collect.py
@@ -25,7 +25,8 @@ def collect_script(instance, base_dir, script, script_name):
         script.encode(), rcs=False,
         description='collect: {}'.format(script_name))
     if err:
-        LOG.debug("collect script %s had stderr: %s", script_name, err)
+        LOG.debug("collect script %s exited '%s' and had stderr: %s",
+                  script_name, err, exit)
     if not isinstance(out, bytes):
         raise util.PlatformError(
             "Collection of '%s' returned type %s, expected bytes: %s" %
diff --git a/tests/cloud_tests/platforms/instances.py b/tests/cloud_tests/platforms/instances.py
index 3bad021..cc439d2 100644
--- a/tests/cloud_tests/platforms/instances.py
+++ b/tests/cloud_tests/platforms/instances.py
@@ -108,7 +108,7 @@ class Instance(TargetBase):
                 return client
             except (ConnectionRefusedError, AuthenticationException,
                     BadHostKeyException, ConnectionResetError, SSHException,
-                    OSError) as e:
+                    OSError):
                 retries -= 1
                 time.sleep(10)
 
diff --git a/tests/cloud_tests/platforms/lxd/instance.py b/tests/cloud_tests/platforms/lxd/instance.py
index 0d957bc..1c17c78 100644
--- a/tests/cloud_tests/platforms/lxd/instance.py
+++ b/tests/cloud_tests/platforms/lxd/instance.py
@@ -152,9 +152,8 @@ class LXDInstance(Instance):
                 return fp.read()
 
         try:
-            stdout, stderr = subp(
-                ['lxc', 'console', '--show-log', self.name], decode=False)
-            return stdout
+            return subp(['lxc', 'console', '--show-log', self.name],
+                        decode=False)[0]
         except ProcessExecutionError as e:
             raise PlatformError(
                 "console log",
@@ -214,11 +213,10 @@ def _has_proper_console_support():
             reason = "LXD Driver version not 3.x+ (%s)" % dver
         else:
             try:
-                stdout, stderr = subp(['lxc', 'console', '--help'],
-                                      decode=False)
+                stdout = subp(['lxc', 'console', '--help'], decode=False)[0]
                 if not (b'console' in stdout and b'log' in stdout):
                     reason = "no '--log' in lxc console --help"
-            except ProcessExecutionError as e:
+            except ProcessExecutionError:
                 reason = "no 'console' command in lxc client"
 
     if reason:
diff --git a/tests/cloud_tests/setup_image.py b/tests/cloud_tests/setup_image.py
index 6d24211..4e19570 100644
--- a/tests/cloud_tests/setup_image.py
+++ b/tests/cloud_tests/setup_image.py
@@ -25,10 +25,9 @@ def installed_package_version(image, package, ensure_installed=True):
     else:
         raise NotImplementedError
 
-    msg = 'query version for package: {}'.format(package)
-    (out, err, exit) = image.execute(
-        cmd, description=msg, rcs=(0,) if ensure_installed else range(0, 256))
-    return out.strip()
+    return image.execute(
+        cmd, description='query version for package: {}'.format(package),
+        rcs=(0,) if ensure_installed else range(0, 256))[0].strip()
 
 
 def install_deb(args, image):
@@ -54,7 +53,7 @@ def install_deb(args, image):
          remote_path], description=msg)
     # check installed deb version matches package
     fmt = ['-W', "--showformat=${Version}"]
-    (out, err, exit) = image.execute(['dpkg-deb'] + fmt + [remote_path])
+    out = image.execute(['dpkg-deb'] + fmt + [remote_path])[0]
     expected_version = out.strip()
     found_version = installed_package_version(image, 'cloud-init')
     if expected_version != found_version:
@@ -85,7 +84,7 @@ def install_rpm(args, image):
     image.execute(['rpm', '-U', remote_path], description=msg)
 
     fmt = ['--queryformat', '"%{VERSION}"']
-    (out, err, exit) = image.execute(['rpm', '-q'] + fmt + [remote_path])
+    (out, _err, _exit) = image.execute(['rpm', '-q'] + fmt + [remote_path])
     expected_version = out.strip()
     found_version = installed_package_version(image, 'cloud-init')
     if expected_version != found_version:
diff --git a/tests/cloud_tests/testcases/base.py b/tests/cloud_tests/testcases/base.py
index 7598d46..e3dcab3 100644
--- a/tests/cloud_tests/testcases/base.py
+++ b/tests/cloud_tests/testcases/base.py
@@ -159,7 +159,7 @@ class CloudTestCase(unittest.TestCase):
         expected_net_keys = [
             'public-ipv4s', 'ipv4-associations', 'local-hostname',
             'public-hostname']
-        for mac, mac_data in macs.items():
+        for mac_data in macs.values():
             for key in expected_net_keys:
                 self.assertIn(key, mac_data)
         self.assertIsNotNone(
diff --git a/tests/cloud_tests/testcases/examples/including_user_groups.py b/tests/cloud_tests/testcases/examples/including_user_groups.py
index 93b7a82..4067348 100644
--- a/tests/cloud_tests/testcases/examples/including_user_groups.py
+++ b/tests/cloud_tests/testcases/examples/including_user_groups.py
@@ -42,7 +42,7 @@ class TestUserGroups(base.CloudTestCase):
 
     def test_user_root_in_secret(self):
         """Test root user is in 'secret' group."""
-        user, _, groups = self.get_data_file('root_groups').partition(":")
+        _user, _, groups = self.get_data_file('root_groups').partition(":")
         self.assertIn("secret", groups.split(),
                       msg="User root is not in group 'secret'")
 
diff --git a/tests/cloud_tests/testcases/modules/user_groups.py b/tests/cloud_tests/testcases/modules/user_groups.py
index 93b7a82..4067348 100644
--- a/tests/cloud_tests/testcases/modules/user_groups.py
+++ b/tests/cloud_tests/testcases/modules/user_groups.py
@@ -42,7 +42,7 @@ class TestUserGroups(base.CloudTestCase):
 
     def test_user_root_in_secret(self):
         """Test root user is in 'secret' group."""
-        user, _, groups = self.get_data_file('root_groups').partition(":")
+        _user, _, groups = self.get_data_file('root_groups').partition(":")
         self.assertIn("secret", groups.split(),
                       msg="User root is not in group 'secret'")
 
diff --git a/tests/cloud_tests/util.py b/tests/cloud_tests/util.py
index 3dd4996..06f7d86 100644
--- a/tests/cloud_tests/util.py
+++ b/tests/cloud_tests/util.py
@@ -358,7 +358,7 @@ class TargetBase(object):
         # when sh is invoked with '-c', then the first argument is "$0"
         # which is commonly understood as the "program name".
         # 'read_data' is the program name, and 'remote_path' is '$1'
-        stdout, stderr, rc = self._execute(
+        stdout, _stderr, rc = self._execute(
             ["sh", "-c", 'exec cat "$1"', 'read_data', remote_path])
         if rc != 0:
             raise RuntimeError("Failed to read file '%s'" % remote_path)
diff --git a/tests/unittests/test__init__.py b/tests/unittests/test__init__.py
index 25878d7..f1ab02e 100644
--- a/tests/unittests/test__init__.py
+++ b/tests/unittests/test__init__.py
@@ -214,7 +214,7 @@ class TestCmdlineUrl(CiTestCase):
     def test_no_key_found(self, m_read):
         cmdline = "ro mykey=http://example.com/foo root=foo"
         fpath = self.tmp_path("ccpath")
-        lvl, msg = main.attempt_cmdline_url(
+        lvl, _msg = main.attempt_cmdline_url(
             fpath, network=True, cmdline=cmdline)
 
         m_read.assert_not_called()
diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py
index 3e8b791..88fe76c 100644
--- a/tests/unittests/test_datasource/test_azure.py
+++ b/tests/unittests/test_datasource/test_azure.py
@@ -214,7 +214,7 @@ scbus-1 on xpt0 bus 0
                 self.assertIn(tag, x)
 
         def tags_equal(x, y):
-            for x_tag, x_val in x.items():
+            for x_val in x.values():
                 y_val = y.get(x_val.tag)
                 self.assertEqual(x_val.text, y_val.text)
 
@@ -1216,7 +1216,7 @@ class TestAzureDataSourcePreprovisioning(CiTestCase):
         fake_resp.return_value = mock.MagicMock(status_code=200, text=content,
                                                 content=content)
         dsa = dsaz.DataSourceAzure({}, distro=None, paths=self.paths)
-        md, ud, cfg, d = dsa._reprovision()
+        md, _ud, cfg, _d = dsa._reprovision()
         self.assertEqual(md['local-hostname'], hostname)
         self.assertEqual(cfg['system_info']['default_user']['name'], username)
         self.assertEqual(fake_resp.call_args_list,
diff --git a/tests/unittests/test_datasource/test_maas.py b/tests/unittests/test_datasource/test_maas.py
index 6e4031c..c84d067 100644
--- a/tests/unittests/test_datasource/test_maas.py
+++ b/tests/unittests/test_datasource/test_maas.py
@@ -53,7 +53,7 @@ class TestMAASDataSource(CiTestCase):
         my_d = os.path.join(self.tmp, "valid_extra")
         populate_dir(my_d, data)
 
-        ud, md, vd = DataSourceMAAS.read_maas_seed_dir(my_d)
+        ud, md, _vd = DataSourceMAAS.read_maas_seed_dir(my_d)
 
         self.assertEqual(userdata, ud)
         for key in ('instance-id', 'local-hostname'):
@@ -149,7 +149,7 @@ class TestMAASDataSource(CiTestCase):
             'meta-data/local-hostname': 'test-hostname',
             'meta-data/vendor-data': yaml.safe_dump(expected_vd).encode(),
         }
-        ud, md, vd = self.mock_read_maas_seed_url(
+        _ud, md, vd = self.mock_read_maas_seed_url(
             valid, "http://example.com/foo")
 
         self.assertEqual(valid['meta-data/instance-id'], md['instance-id'])
diff --git a/tests/unittests/test_datasource/test_nocloud.py b/tests/unittests/test_datasource/test_nocloud.py
index 70d50de..cdbd1e1 100644
--- a/tests/unittests/test_datasource/test_nocloud.py
+++ b/tests/unittests/test_datasource/test_nocloud.py
@@ -51,9 +51,6 @@ class TestNoCloudDataSource(CiTestCase):
         class PsuedoException(Exception):
             pass
 
-        def my_find_devs_with(*args, **kwargs):
-            raise PsuedoException
-
         self.mocks.enter_context(
             mock.patch.object(util, 'find_devs_with',
                               side_effect=PsuedoException))
diff --git a/tests/unittests/test_handler/test_handler_apt_source_v3.py b/tests/unittests/test_handler/test_handler_apt_source_v3.py
index 7bb1b7c..e486862 100644
--- a/tests/unittests/test_handler/test_handler_apt_source_v3.py
+++ b/tests/unittests/test_handler/test_handler_apt_source_v3.py
@@ -528,7 +528,7 @@ class TestAptSourceConfig(t_help.FilesystemMockingTestCase):
 
         expected = sorted([npre + suff for opre, npre, suff in files])
         # create files
-        for (opre, npre, suff) in files:
+        for (opre, _npre, suff) in files:
             fpath = os.path.join(apt_lists_d, opre + suff)
             util.write_file(fpath, content=fpath)
 
diff --git a/tests/unittests/test_handler/test_handler_ntp.py b/tests/unittests/test_handler/test_handler_ntp.py
index 02676aa..17c5355 100644
--- a/tests/unittests/test_handler/test_handler_ntp.py
+++ b/tests/unittests/test_handler/test_handler_ntp.py
@@ -76,7 +76,7 @@ class TestNtp(FilesystemMockingTestCase):
             template = TIMESYNCD_TEMPLATE
         else:
             template = NTP_TEMPLATE
-        (confpath, template_fn) = self._generate_template(template=template)
+        (confpath, _template_fn) = self._generate_template(template=template)
         ntpconfig = copy.deepcopy(dcfg[client])
         ntpconfig['confpath'] = confpath
         ntpconfig['template_name'] = os.path.basename(confpath)
diff --git a/tests/unittests/test_templating.py b/tests/unittests/test_templating.py
index 1080e13..20c87ef 100644
--- a/tests/unittests/test_templating.py
+++ b/tests/unittests/test_templating.py
@@ -50,12 +50,12 @@ class TestTemplates(test_helpers.CiTestCase):
     def test_detection(self):
         blob = "## template:cheetah"
 
-        (template_type, renderer, contents) = templater.detect_template(blob)
+        (template_type, _renderer, contents) = templater.detect_template(blob)
         self.assertIn("cheetah", template_type)
         self.assertEqual("", contents.strip())
 
         blob = "blahblah $blah"
-        (template_type, renderer, contents) = templater.detect_template(blob)
+        (template_type, _renderer, _contents) = templater.detect_template(blob)
         self.assertIn("cheetah", template_type)
         self.assertEqual(blob, contents)
 
diff --git a/tests/unittests/test_util.py b/tests/unittests/test_util.py
index 5010190..5637c4e 100644
--- a/tests/unittests/test_util.py
+++ b/tests/unittests/test_util.py
@@ -772,11 +772,11 @@ class TestSubp(helpers.CiTestCase):
 
     def test_subp_reads_env(self):
         with mock.patch.dict("os.environ", values={'FOO': 'BAR'}):
-            out, err = util.subp(self.printenv + ['FOO'], capture=True)
+            out, _err = util.subp(self.printenv + ['FOO'], capture=True)
         self.assertEqual('FOO=BAR', out.splitlines()[0])
 
     def test_subp_env_and_update_env(self):
-        out, err = util.subp(
+        out, _err = util.subp(
             self.printenv + ['FOO', 'HOME', 'K1', 'K2'], capture=True,
             env={'FOO': 'BAR'},
             update_env={'HOME': '/myhome', 'K2': 'V2'})
@@ -786,7 +786,7 @@ class TestSubp(helpers.CiTestCase):
     def test_subp_update_env(self):
         extra = {'FOO': 'BAR', 'HOME': '/root', 'K1': 'V1'}
         with mock.patch.dict("os.environ", values=extra):
-            out, err = util.subp(
+            out, _err = util.subp(
                 self.printenv + ['FOO', 'HOME', 'K1', 'K2'], capture=True,
                 update_env={'HOME': '/myhome', 'K2': 'V2'})