Gated dbus for os families that use it

Gated the dbus include for os families that are currently using it
within this module at this time.

Renamed some defs to more appropriately express their function.

salt/modules/localemod.py

@@ -8,7 +8,12 @@ from __future__ import absolute_import
 import logging
 import re
 import os
-import dbus
+HAS_DBUS = False
+try:
+    import dbus
+    HAS_DBUS = True
+except ImportError:
+    pass
 
 # Import salt libs
 import salt.utils
@@ -25,14 +30,26 @@ def __virtual__():
     '''
     Only work on POSIX-like systems
     '''
+    if HAS_DBUS is False and _uses_dbus():
+        return False
     if salt.utils.is_windows():
         return False
+
     return __virtualname__
 
+def _uses_dbus():
+    if 'Arch' in __grains__['os_family']:
+        return True
+    elif 'RedHat' in __grains__['os_family']:
+        return False
+    elif 'Debian' in __grains__['os_family']:
+        return False
+    elif 'Gentoo' in __grains__['os_family']:
+        return False
 
-def _parse_localectl():
+def _parse_dbus_locale():
     '''
-    Get the 'System Locale' parameters from localectl
+    Get the 'System Locale' parameters from dbus
     '''
     ret = {}
 
@@ -55,11 +72,11 @@ def _parse_localectl():
     return ret
 
 
-def _localectl_get():
+def _locale_get():
     '''
-    Use systemd's localectl command to get the current locale
+    Use dbus to get the current locale
     '''
-    return _parse_localectl().get('LANG', '')
+    return _parse_dbus_locale().get('LANG', '')
 
 
 def _localectl_set(locale=''):
@@ -67,7 +84,7 @@ def _localectl_set(locale=''):
     Use systemd's localectl command to set the LANG locale parameter, making
     sure not to trample on other params that have been set.
     '''
-    locale_params = _parse_localectl()
+    locale_params = _parse_dbus_locale()
     locale_params['LANG'] = str(locale)
     args = ' '.join(['{0}="{1}"'.format(k, v)
                      for k, v in six.iteritems(locale_params)])
@@ -102,7 +119,7 @@ def get_locale():
     '''
     cmd = ''
     if 'Arch' in __grains__['os_family']:
-        return _localectl_get()
+        return _locale_get()
     elif 'RedHat' in __grains__['os_family']:
         cmd = 'grep "^LANG=" /etc/sysconfig/i18n'
     elif 'Debian' in __grains__['os_family']:

tests/unit/modules/localemod_test.py

@@ -41,7 +41,7 @@ class LocalemodTestCase(TestCase):
         Test for Get the current system locale
         '''
         with patch.dict(localemod.__grains__, {'os_family': ['Arch']}):
-            with patch.object(localemod, '_localectl_get', return_value=True):
+            with patch.object(localemod, '_locale_get', return_value=True):
                 self.assertTrue(localemod.get_locale())
 
         with patch.dict(localemod.__grains__, {'os_family': ['Gentoo']}):