NF: allow customization configuration under corresponding .d directories (Closes gh-114)

Additional changes:
  ENH: make basedir for Config's a kwarg to the constructor
  ENH: improved analysis/reporting on presence/accessibility of config
       files.  Got carried away and forgot about existing  work done by
	   Steven Hiscocks in the gh-115 -- will merge it in the next
       commit for the fair ack of his work

Now for any X.conf configuration file we have following ways to
provide customizations

  X.local -- read after .conf (kept for backward compatibility)
  X.d/ -- directory to contain additional .conf files, sorted
               alphabetically, e.g
  X.d/01_enable.conf       - to enable the jail
  X.d/02_custom_port.conf  - to change the port

X could be a 'jail' or 'fail2ban' or any other configuration file in
fail2ban.

Mention that all files still must contain the corresponding sections
(most of the time duplicating it across all of them).

client/actionreader.py

@@ -35,8 +35,8 @@ logSys = logging.getLogger("fail2ban.client.config")
 
 class ActionReader(ConfigReader):
 	
-	def __init__(self, action, name):
-		ConfigReader.__init__(self)
+	def __init__(self, action, name, **kwargs):
+		ConfigReader.__init__(self, **kwargs)
 		self.__file = action[0]
 		self.__cInfo = action[1]
 		self.__name = name

client/configreader.py

@@ -27,7 +27,7 @@ __date__ = "$Date$"
 __copyright__ = "Copyright (c) 2004 Cyril Jaquier"
 __license__ = "GPL"
 
-import logging, os
+import glob, logging, os
 from configparserinc import SafeConfigParserWithIncludes
 from ConfigParser import NoOptionError, NoSectionError
 
@@ -35,36 +35,64 @@ from ConfigParser import NoOptionError, NoSectionError
 logSys = logging.getLogger("fail2ban.client.config")
 
 class ConfigReader(SafeConfigParserWithIncludes):
+
+	DEFAULT_BASEDIR = '/etc/fail2ban'
 	
-	BASE_DIRECTORY = "/etc/fail2ban/"
-	
-	def __init__(self):
+	def __init__(self, basedir=None):
 		SafeConfigParserWithIncludes.__init__(self)
+		self.setBaseDir(basedir)
 		self.__opts = None
 	
-	#@staticmethod
-	def setBaseDir(folderName):
-		path = folderName.rstrip('/')
-		ConfigReader.BASE_DIRECTORY = path + '/'
-	setBaseDir = staticmethod(setBaseDir)
-		
-	#@staticmethod
-	def getBaseDir():
-		return ConfigReader.BASE_DIRECTORY
-	getBaseDir = staticmethod(getBaseDir)
+	def setBaseDir(self, basedir):
+		if basedir is None:
+			basedir = ConfigReader.DEFAULT_BASEDIR	# stock system location
+		if not (os.path.exists(basedir) and os.access(basedir, os.R_OK | os.X_OK)):
+			raise ValueError("Base configuration directory %s either does not exist "
+							 "or is not accessible" % basedir)
+		self._basedir = basedir.rstrip('/')
+	
+	def getBaseDir(self):
+		return self._basedir
 	
 	def read(self, filename):
-		basename = ConfigReader.BASE_DIRECTORY + filename
+		basename = os.path.join(self._basedir, filename)
 		logSys.debug("Reading " + basename)
-		bConf = basename + ".conf"
-		bLocal = basename + ".local"
-		if os.path.exists(bConf) or os.path.exists(bLocal):
-			SafeConfigParserWithIncludes.read(self, [bConf, bLocal])
+		config_files = [ basename + ".conf",
+						 basename + ".local" ]
+
+		# choose only existing ones
+		config_files = filter(os.path.exists, config_files)
+
+		# possible further customizations under a .conf.d directory
+		config_dir = basename + '.d'
+		if os.path.exists(config_dir):
+			if os.path.isdir(config_dir) and os.access(config_dir, os.X_OK | os.R_OK):
+				# files must carry .conf suffix as well
+				config_files += sorted(glob.glob('%s/*.conf' % config_dir))
+			else:
+				logSys.warn("%s exists but not a directory or not accessible"
+							 % config_dir)
+
+		# check if files are accessible, warn if any is not accessible
+		# and remove it from the list
+		config_files_accessible = []
+		for f in config_files:
+			if os.access(f, os.R_OK):
+				config_files_accessible.append(f)
+			else:
+				logSys.warn("%s exists but not accessible - skipping" % f)
+
+		if len(config_files_accessible):
+			# at least one config exists and accessible
+			SafeConfigParserWithIncludes.read(self, config_files_accessible)
 			return True
 		else:
-			logSys.error(bConf + " and " + bLocal + " do not exist")
+			logSys.error("Found no accessible config files for %r " % filename
+						 + (["",
+							 "among existing ones: " + ', '.join(config_files)][bool(len(config_files))]))
+
 			return False
-	
+
 	##
 	# Read the options.
 	#

client/fail2banreader.py

@@ -35,8 +35,8 @@ logSys = logging.getLogger("fail2ban.client.config")
 
 class Fail2banReader(ConfigReader):
 	
-	def __init__(self):
-		ConfigReader.__init__(self)
+	def __init__(self, **kwargs):
+		ConfigReader.__init__(self, **kwargs)
 	
 	def read(self):
 		ConfigReader.read(self, "fail2ban")

client/filterreader.py

@@ -35,8 +35,8 @@ logSys = logging.getLogger("fail2ban.client.config")
 
 class FilterReader(ConfigReader):
 	
-	def __init__(self, fileName, name):
-		ConfigReader.__init__(self)
+	def __init__(self, fileName, name, **kwargs):
+		ConfigReader.__init__(self, **kwargs)
 		self.__file = fileName
 		self.__name = name
 	

client/jailreader.py

@@ -40,8 +40,8 @@ class JailReader(ConfigReader):
 	
 	actionCRE = re.compile("^((?:\w|-|_|\.)+)(?:\[(.*)\])?$")
 	
-	def __init__(self, name):
-		ConfigReader.__init__(self)
+	def __init__(self, name, **kwargs):
+		ConfigReader.__init__(self, **kwargs)
 		self.__name = name
 		self.__filter = None
 		self.__actions = list()
@@ -53,7 +53,7 @@ class JailReader(ConfigReader):
 		return self.__name
 	
 	def read(self):
-		ConfigReader.read(self, "jail")
+		return ConfigReader.read(self, "jail")
 	
 	def isEnabled(self):
 		return self.__opts["enabled"]
@@ -75,7 +75,8 @@ class JailReader(ConfigReader):
 		
 		if self.isEnabled():
 			# Read filter
-			self.__filter = FilterReader(self.__opts["filter"], self.__name)
+			self.__filter = FilterReader(self.__opts["filter"], self.__name,
+										 basedir=self.getBaseDir())
 			ret = self.__filter.read()
 			if ret:
 				self.__filter.getOptions(self.__opts)
@@ -87,7 +88,7 @@ class JailReader(ConfigReader):
 			for act in self.__opts["action"].split('\n'):
 				try:
 					splitAct = JailReader.splitAction(act)
-					action = ActionReader(splitAct, self.__name)
+					action = ActionReader(splitAct, self.__name, basedir=self.getBaseDir())
 					ret = action.read()
 					if ret:
 						action.getOptions(self.__opts)

client/jailsreader.py

@@ -36,12 +36,12 @@ logSys = logging.getLogger("fail2ban.client.config")
 
 class JailsReader(ConfigReader):
 	
-	def __init__(self):
-		ConfigReader.__init__(self)
+	def __init__(self, **kwargs):
+		ConfigReader.__init__(self, **kwargs)
 		self.__jails = list()
 	
 	def read(self):
-		ConfigReader.read(self, "jail")
+		return ConfigReader.read(self, "jail")
 	
 	def getOptions(self, section = None):
 		opts = []
@@ -49,7 +49,7 @@ class JailsReader(ConfigReader):
 
 		if section:
 			# Get the options of a specific jail.
-			jail = JailReader(section)
+			jail = JailReader(section, basedir=self.getBaseDir())
 			jail.read()
 			ret = jail.getOptions()
 			if ret:
@@ -62,7 +62,7 @@ class JailsReader(ConfigReader):
 		else:
 			# Get the options of all jails.
 			for sec in self.sections():
-				jail = JailReader(sec)
+				jail = JailReader(sec, basedir=self.getBaseDir())
 				jail.read()
 				ret = jail.getOptions()
 				if ret: