Stylistic improvements from quantum-rootwrap

As part of the convergence effort between oslo-rootwrap and
quantum-rootwrap, import stylistic improvements introduced
in quantum-rootwrap, like:

- HACKING-compliant docstrings
- More elegant return construct from match_filter in filters.py
- Remove overridden use of filters in wrapper.py

Change-Id: I49a97271b1c385feb25adf4f62add5c71962b5dd

2 files changed, 13 insertions, 15 deletions

diff --git a/openstack/common/rootwrap/filters.py b/openstack/common/rootwrap/filters.py
index d9618af..58121cb 100644
--- a/openstack/common/rootwrap/filters.py
+++ b/openstack/common/rootwrap/filters.py
@@ -20,7 +20,7 @@ import re
 
 
 class CommandFilter(object):
-    """Command filter only checking that the 1st argument matches exec_path"""
+    """Command filter only checking that the 1st argument matches exec_path."""
 
     def __init__(self, exec_path, run_as, *args):
         self.name = ''
@@ -30,7 +30,7 @@ class CommandFilter(object):
         self.real_exec = None
 
     def get_exec(self, exec_dirs=[]):
-        """Returns existing executable, or empty string if none found"""
+        """Returns existing executable, or empty string if none found."""
         if self.real_exec is not None:
             return self.real_exec
         self.real_exec = ""
@@ -46,10 +46,8 @@ class CommandFilter(object):
         return self.real_exec
 
     def match(self, userargs):
-        """Only check that the first argument (command) matches exec_path"""
-        if (os.path.basename(self.exec_path) == userargs[0]):
-            return True
-        return False
+        """Only check that the first argument (command) matches exec_path."""
+        return os.path.basename(self.exec_path) == userargs[0]
 
     def get_command(self, userargs, exec_dirs=[]):
         """Returns command to execute (with sudo -u if run_as != root)."""
@@ -60,12 +58,12 @@ class CommandFilter(object):
         return [to_exec] + userargs[1:]
 
     def get_environment(self, userargs):
-        """Returns specific environment to set, None if none"""
+        """Returns specific environment to set, None if none."""
         return None
 
 
 class RegExpFilter(CommandFilter):
-    """Command filter doing regexp matching for every argument"""
+    """Command filter doing regexp matching for every argument."""
 
     def match(self, userargs):
         # Early skip if command or number of args don't match
@@ -135,7 +133,7 @@ class PathFilter(CommandFilter):
 
 
 class DnsmasqFilter(CommandFilter):
-    """Specific filter for the dnsmasq call (which includes env)"""
+    """Specific filter for the dnsmasq call (which includes env)."""
 
     CONFIG_FILE_ARG = 'CONFIG_FILE'
 
@@ -160,7 +158,7 @@ class DnsmasqFilter(CommandFilter):
 
 
 class DeprecatedDnsmasqFilter(DnsmasqFilter):
-    """Variant of dnsmasq filter to support old-style FLAGFILE"""
+    """Variant of dnsmasq filter to support old-style FLAGFILE."""
     CONFIG_FILE_ARG = 'FLAGFILE'
 
 
@@ -210,7 +208,7 @@ class KillFilter(CommandFilter):
 
 
 class ReadFileFilter(CommandFilter):
-    """Specific filter for the utils.read_file_as_root call"""
+    """Specific filter for the utils.read_file_as_root call."""
 
     def __init__(self, file_path, *args):
         self.file_path = file_path
diff --git a/openstack/common/rootwrap/wrapper.py b/openstack/common/rootwrap/wrapper.py
index e0ac9df..d488ddd 100644
--- a/openstack/common/rootwrap/wrapper.py
+++ b/openstack/common/rootwrap/wrapper.py
@@ -93,7 +93,7 @@ def setup_syslog(execname, facility, level):
 
 
 def build_filter(class_name, *args):
-    """Returns a filter object of class class_name"""
+    """Returns a filter object of class class_name."""
     if not hasattr(filters, class_name):
         logging.warning("Skipping unknown filter class (%s) specified "
                         "in filter definitions" % class_name)
@@ -103,7 +103,7 @@ def build_filter(class_name, *args):
 
 
 def load_filters(filters_path):
-    """Load filters from a list of directories"""
+    """Load filters from a list of directories."""
     filterlist = []
     for filterdir in filters_path:
         if not os.path.isdir(filterdir):
@@ -121,7 +121,7 @@ def load_filters(filters_path):
     return filterlist
 
 
-def match_filter(filters, userargs, exec_dirs=[]):
+def match_filter(filter_list, userargs, exec_dirs=[]):
     """
     Checks user command and arguments through command filters and
     returns the first matching filter.
@@ -131,7 +131,7 @@ def match_filter(filters, userargs, exec_dirs=[]):
     """
     first_not_executable_filter = None
 
-    for f in filters:
+    for f in filter_list:
         if f.match(userargs):
             # Try other filters if executable is absent
             if not f.get_exec(exec_dirs=exec_dirs):