really skips invalid jails (because of theirs wrong configuration) - server starts nevertheless, as long as one jail was successful configured;

message about wrong jail configuration logged in client log (stdout, systemd journal etc.) and in server log as error

fail2ban/client/jailreader.py

@@ -118,10 +118,12 @@ class JailReader(ConfigReader):
 		defsec = self._cfg.get_defaults()
 		defsec["fail2ban_version"] = version
 
+		try:
+
 			# Read first options only needed for merge defaults ('known/...' from filter):
 			self.__opts = ConfigReader.getOptions(self, self.__name, opts1st, shouldExist=True)
 			if not self.__opts:
-			return False
+				raise ValueError("Init jail options failed")
 			
 			if self.isEnabled():
 				# Read filter
@@ -135,8 +137,7 @@ class JailReader(ConfigReader):
 					self.__filter.getOptions(self.__opts)
 					ConfigReader.merge_section(self, self.__name, self.__filter.getCombined(), 'known/')
 					if not ret:
-					logSys.error("Unable to read the filter")
-					return False
+						raise ValueError("Unable to read the filter %r" % filterName)
 				else:
 					self.__filter = None
 					logSys.warning("No filter set for jail %s" % self.__name)
@@ -144,7 +145,7 @@ class JailReader(ConfigReader):
 				# Read second all options (so variables like %(known/param) can be interpolated):
 				self.__opts = ConfigReader.getOptions(self, self.__name, opts)
 				if not self.__opts:
-				return False
+					raise ValueError("Read jail options failed")
 			
 				# cumulate filter options again (ignore given in jail):
 				if self.__filter:
@@ -177,11 +178,18 @@ class JailReader(ConfigReader):
 							else:
 								raise AttributeError("Unable to read action")
 					except Exception as e:
-					logSys.error("Error in action definition " + act)
 						logSys.debug("Caught exception: %s" % (e,))
-					return False
+						raise ValueError("Error in action definition %r" % e)
 				if not len(self.__actions):
 					logSys.warning("No actions were defined for %s" % self.__name)
+			
+		except ValueError as e:
+			e = str(e)
+			logSys.error(e)
+			if not self.__opts:
+				self.__opts = dict()
+			self.__opts['config-error'] = e
+			return False
 		return True
 	
 	def convert(self, allow_no_files=False):
@@ -195,6 +203,10 @@ class JailReader(ConfigReader):
 		 """
 
 		stream = []
+		e = self.__opts.get('config-error')
+		if e:
+			stream.extend([['config-error', "Jail '%s' skipped, because of wrong configuration: %s" % (self.__name, e)]])
+			return stream
 		for opt, value in self.__opts.iteritems():
 			if opt == "logpath" and	\
 					not self.__opts.get('backend', None).startswith("systemd"):

fail2ban/client/jailsreader.py

@@ -66,7 +66,7 @@ class JailsReader(ConfigReader):
 			sections = [ section ]
 
 		# Get the options of all jails.
-		parse_status = True
+		parse_status = None
 		for sec in sections:
 			if sec == 'INCLUDES':
 				continue
@@ -77,11 +77,17 @@ class JailsReader(ConfigReader):
 			ret = jail.getOptions()
 			if ret:
 				if jail.isEnabled():
+					# at least one jail was successful:
+					parse_status = True
 					# We only add enabled jails
 					self.__jails.append(jail)
 			else:
 				logSys.error("Errors in jail %r. Skipping..." % sec)
+				self.__jails.append(jail)
+				if parse_status is None:
 					parse_status = False
+		if parse_status is None:
+			parse_status = True
 		return parse_status
 
 	def convert(self, allow_no_files=False):
@@ -103,6 +109,7 @@ class JailsReader(ConfigReader):
 			stream.extend(jail.convert(allow_no_files=allow_no_files))
 		# Start jails
 		for jail in self.__jails:
+			if not jail.options.get('config-error'):
 				stream.append(["start", jail.getName()])
 
 		return stream

fail2ban/server/transmitter.py

@@ -131,6 +131,9 @@ class Transmitter:
 			return self.status(command[1:])
 		elif command[0] == "version":
 			return version.version
+		elif command[0] == "config-error":
+			logSys.error(command[1])
+			return None
 		raise Exception("Invalid command")
 	
 	def __commandSet(self, command, multiple=False):