pylint: pay attention to unused variable warnings.

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

11 files changed, 28 insertions, 36 deletions

diff --git a/cloudinit/sources/DataSourceAliYun.py b/cloudinit/sources/DataSourceAliYun.py
index 22279d09..858e0827 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 0ee622e2..a71197a6 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 6ac88635..aa56addb 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 dc914a72..178ccb0f 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 e55a7638..fb166ae1 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 693f8d5c..0e7cccac 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 26f3168d..a4cf0667 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 2d8900e2..3ef8c624 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 75cfbaaf..8c91fa41 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 44075255..a590f323 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 e7fda22a..452e9219 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])