PY3(BF): config reader -- handle __name__ interpolation

fail2ban/client/configparserinc.py

@@ -28,15 +28,45 @@ __copyright__ = 'Copyright (c) 2007 Yaroslav Halchenko'
 __license__ = 'GPL'
 
 import logging, os, sys
+
 if sys.version_info >= (3,2): # pragma: no cover
-	# SafeConfigParser deprecitated from python 3.2 (renamed ConfigParser)
-	from configparser import ConfigParser as SafeConfigParser
+
+	# SafeConfigParser deprecated from Python 3.2 (renamed to ConfigParser)
+	from configparser import ConfigParser as SafeConfigParser, \
+		BasicInterpolation
+
+	# And interpolation of __name__ was simply removed, thus we need to
+	# decorate default interpolator to handle it
+	class BasicInterpolationWithName(BasicInterpolation):
+		"""Decorator to bring __name__ interpolation back.
+
+		Original handling of __name__ was removed because of
+		functional deficiencies: http://bugs.python.org/issue10489
+
+		commit v3.2a4-105-g61f2761
+		Author: Lukasz Langa <lukasz@langa.pl>
+		Date:	Sun Nov 21 13:41:35 2010 +0000
+
+		Issue #10489: removed broken `__name__` support from configparser
+
+		But should be fine to reincarnate for our use case
+		"""
+		def _interpolate_some(self, parser, option, accum, rest, section, map,
+							  depth):
+			if section and not (__name__ in map):
+				map = map.copy()		  # just to be safe
+				map['__name__'] = section
+			return super(BasicInterpolationWithName, self)._interpolate_some(
+				parser, option, accum, rest, section, map, depth)
+
 else: # pragma: no cover
 	from ConfigParser import SafeConfigParser
 
 # Gets the instance of the logger.
 logSys = logging.getLogger(__name__)
 
+__all__ = ['SafeConfigParserWithIncludes']
+
 class SafeConfigParserWithIncludes(SafeConfigParser):
 	"""
 	Class adds functionality to SafeConfigParser to handle included
@@ -68,6 +98,14 @@ after = 1.conf
 
 	SECTION_NAME = "INCLUDES"
 
+	if sys.version_info >= (3,2):
+		# overload constructor only for fancy new Python3's
+		def __init__(self, *args, **kwargs):
+			kwargs = kwargs.copy()
+			kwargs['interpolation'] = BasicInterpolationWithName()
+			super(SafeConfigParserWithIncludes, self).__init__(
+				*args, **kwargs)
+
 	#@staticmethod
 	def getIncludes(resource, seen = []):
 		"""

fail2ban/tests/clientreadertestcase.py

@@ -21,7 +21,7 @@ __author__ = "Cyril Jaquier, Yaroslav Halchenko"
 __copyright__ = "Copyright (c) 2004 Cyril Jaquier, 2011-2013 Yaroslav Halchenko"
 __license__ = "GPL"
 
-import os, shutil, tempfile, unittest
+import os, shutil, sys, tempfile, unittest
 
 from fail2ban.client.configreader import ConfigReader
 from fail2ban.client.jailreader import JailReader
@@ -47,7 +47,7 @@ class ConfigReaderTest(unittest.TestCase):
 		"""Call after every test case."""
 		shutil.rmtree(self.d)
 
-	def _write(self, fname, value):
+	def _write(self, fname, value=None, content=None):
 		# verify if we don't need to create .d directory
 		if os.path.sep in fname:
 			d = os.path.dirname(fname)
@@ -55,10 +55,13 @@ class ConfigReaderTest(unittest.TestCase):
 			if not os.path.exists(d_):
 				os.makedirs(d_)
 		f = open("%s/%s" % (self.d, fname), "w")
-		f.write("""
+		if value is not None:
+			f.write("""
 [section]
 option = %s
-""" % value)
+	""" % value)
+		if content is not None:
+			f.write(content)
 		f.close()
 
 	def _remove(self, fname):
@@ -105,6 +108,28 @@ option = %s
 		self._remove("c.local")
 		self.assertEqual(self._getoption(), 1)
 
+	def testInterpolations(self):
+		self.assertFalse(self.c.read('i'))	# nothing is there yet
+		self._write("i.conf", value=None, content="""
+[DEFAULT]
+b = a
+zz = the%(__name__)s
+
+[section]
+y = 4%(b)s
+e = 5${b}
+z = %(__name__)s
+
+[section2]
+z = 3%(__name__)s
+""")
+		self.assertTrue(self.c.read('i'))
+		self.assertEqual(self.c.sections(), ['section', 'section2'])
+		self.assertEqual(self.c.get('section', 'y'), '4a')	 # basic interpolation works
+		self.assertEqual(self.c.get('section', 'e'), '5${b}') # no extended interpolation
+		self.assertEqual(self.c.get('section', 'z'), 'section') # __name__ works
+		self.assertEqual(self.c.get('section', 'zz'), 'thesection') # __name__ works even 'delayed'
+		self.assertEqual(self.c.get('section2', 'z'), '3section2') # and differs per section ;)
 
 class JailReaderTest(unittest.TestCase):