# Copyright 2001-2010 by Vinay Sajip. All Rights Reserved. # # Permission to use, copy, modify, and distribute this software and its # documentation for any purpose and without fee is hereby granted, # provided that the above copyright notice appear in all copies and that # both that copyright notice and this permission notice appear in # supporting documentation, and that the name of Vinay Sajip # not be used in advertising or publicity pertaining to distribution # of the software without specific, written prior permission. # VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING # ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL # VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR # ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER # IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """ Configuration functions for the logging package for Python. The core package is based on PEP 282 and comments thereto in comp.lang.python, and influenced by Apache's log4j system. Copyright (C) 2001-2010 Vinay Sajip. All Rights Reserved. To use, simply 'import logging' and log away! """ import sys, logging, logging.handlers, socket, struct, os, traceback, re import types, io try: import _thread as thread import threading except ImportError: thread = None from socketserver import ThreadingTCPServer, StreamRequestHandler DEFAULT_LOGGING_CONFIG_PORT = 9030 if sys.platform == "win32": RESET_ERROR = 10054 #WSAECONNRESET else: RESET_ERROR = 104 #ECONNRESET # # The following code implements a socket listener for on-the-fly # reconfiguration of logging. # # _listener holds the server object doing the listening _listener = None def fileConfig(fname, defaults=None, disable_existing_loggers=True): """ Read the logging configuration from a ConfigParser-format file. This can be called several times from an application, allowing an end user the ability to select from various pre-canned configurations (if the developer provides a mechanism to present the choices and load the chosen configuration). """ import configparser cp = configparser.ConfigParser(defaults) if hasattr(fname, 'readline'): cp.readfp(fname) else: cp.read(fname) formatters = _create_formatters(cp) # critical section logging._acquireLock() try: logging._handlers.clear() del logging._handlerList[:] # Handlers add themselves to logging._handlers handlers = _install_handlers(cp, formatters) _install_loggers(cp, handlers, disable_existing_loggers) finally: logging._releaseLock() def _resolve(name): """Resolve a dotted name to a global object.""" name = name.split('.') used = name.pop(0) found = __import__(used) for n in name: used = used + '.' + n try: found = getattr(found, n) except AttributeError: __import__(used) found = getattr(found, n) return found def _strip_spaces(alist): return map(lambda x: x.strip(), alist) def _create_formatters(cp): """Create and return formatters""" flist = cp.get("formatters", "keys") if not len(flist): return {} flist = flist.split(",") flist = _strip_spaces(flist) formatters = {} for form in flist: sectname = "formatter_%s" % form opts = cp.options(sectname) if "format" in opts: fs = cp.get(sectname, "format", 1) else: fs = None if "datefmt" in opts: dfs = cp.get(sectname, "datefmt", 1) else: dfs = None c = logging.Formatter if "class" in opts: class_name = cp.get(sectname, "class") if class_name: c = _resolve(class_name) f = c(fs, dfs) formatters[form] = f return formatters def _install_handlers(cp, formatters): """Install and return handlers""" hlist = cp.get("handlers", "keys") if not len(hlist): return {} hlist = hlist.split(",") hlist = _strip_spaces(hlist) handlers = {} fixups = [] #for inter-handler references for hand in hlist: sectname = "handler_%s" % hand klass = cp.get(sectname, "class") opts = cp.options(sectname) if "formatter" in opts: fmt = cp.get(sectname, "formatter") else: fmt = "" try: klass = eval(klass, vars(logging)) except (AttributeError, NameError): klass = _resolve(klass) args = cp.get(sectname, "args") args = eval(args, vars(logging)) h = klass(*args) if "level" in opts: level = cp.get(sectname, "level") h.setLevel(logging._levelNames[level]) if len(fmt): h.setFormatter(formatters[fmt]) if issubclass(klass, logging.handlers.MemoryHandler): if "target" in opts: target = cp.get(sectname,"target") else: target = "" if len(target): #the target handler may not be loaded yet, so keep for later... fixups.append((h, target)) handlers[hand] = h #now all handlers are loaded, fixup inter-handler references... for h, t in fixups: h.setTarget(handlers[t]) return handlers def _install_loggers(cp, handlers, disable_existing_loggers): """Create and install loggers""" # configure the root first llist = cp.get("loggers", "keys") llist = llist.split(",") llist = list(map(lambda x: x.strip(), llist)) llist.remove("root") sectname = "logger_root" root = logging.root log = root opts = cp.options(sectname) if "level" in opts: level = cp.get(sectname, "level") log.setLevel(logging._levelNames[level]) for h in root.handlers[:]: root.removeHandler(h) hlist = cp.get(sectname, "handlers") if len(hlist): hlist = hlist.split(",") hlist = _strip_spaces(hlist) for hand in hlist: log.addHandler(handlers[hand]) #and now the others... #we don't want to lose the existing loggers, #since other threads may have pointers to them. #existing is set to contain all existing loggers, #and as we go through the new configuration we #remove any which are configured. At the end, #what's left in existing is the set of loggers #which were in the previous configuration but #which are not in the new configuration. existing = list(root.manager.loggerDict.keys()) #The list needs to be sorted so that we can #avoid disabling child loggers of explicitly #named loggers. With a sorted list it is easier #to find the child loggers. existing.sort() #We'll keep the list of existing loggers #which are children of named loggers here... child_loggers = [] #now set up the new ones... for log in llist: sectname = "logger_%s" % log qn = cp.get(sectname, "qualname") opts = cp.options(sectname) if "propagate" in opts: propagate = cp.getint(sectname, "propagate") else: propagate = 1 logger = logging.getLogger(qn) if qn in existing: i = existing.index(qn) prefixed = qn + "." pflen = len(prefixed) num_existing = len(existing) i = i + 1 # look at the entry after qn while (i < num_existing) and (existing[i][:pflen] == prefixed): child_loggers.append(existing[i]) i = i + 1 existing.remove(qn) if "level" in opts: level = cp.get(sectname, "level") logger.setLevel(logging._levelNames[level]) for h in logger.handlers[:]: logger.removeHandler(h) logger.propagate = propagate logger.disabled = 0 hlist = cp.get(sectname, "handlers") if len(hlist): hlist = hlist.split(",") hlist = _strip_spaces(hlist) for hand in hlist: logger.addHandler(handlers[hand]) #Disable any old loggers. There's no point deleting #them as other threads may continue to hold references #and by disabling them, you stop them doing any logging. #However, don't disable children of named loggers, as that's #probably not what was intended by the user. for log in existing: logger = root.manager.loggerDict[log] if log in child_loggers: logger.level = logging.NOTSET logger.handlers = [] logger.propagate = 1 elif disable_existing_loggers: logger.disabled = 1 IDENTIFIER = re.compile('^[a-z_][a-z0-9_]*$', re.I) def valid_ident(s): m = IDENTIFIER.match(s) if not m: raise ValueError('Not a valid Python identifier: %r' % s) return True # The ConvertingXXX classes are wrappers around standard Python containers, # and they serve to convert any suitable values in the container. The # conversion converts base dicts, lists and tuples to their wrapped # equivalents, whereas strings which match a conversion format are converted # appropriately. # # Each wrapper should have a configurator attribute holding the actual # configurator to use for conversion. class ConvertingDict(dict): """A converting dictionary wrapper.""" def __getitem__(self, key): value = dict.__getitem__(self, key) result = self.configurator.convert(value) #If the converted value is different, save for next time if value is not result: self[key] = result if type(result) in (ConvertingDict, ConvertingList, ConvertingTuple): result.parent = self result.key = key return result def get(self, key, default=None): value = dict.get(self, key, default) result = self.configurator.convert(value) #If the converted value is different, save for next time if value is not result: self[key] = result if type(result) in (ConvertingDict, ConvertingList, ConvertingTuple): result.parent = self result.key = key return result def pop(self, key, default=None): value = dict.pop(self, key, default) result = self.configurator.convert(value) if value is not result: if type(result) in (ConvertingDict, ConvertingList, ConvertingTuple): result.parent = self result.key = key return result class ConvertingList(list): """A converting list wrapper.""" def __getitem__(self, key): value = list.__getitem__(self, key) result = self.configurator.convert(value) #If the converted value is different, save for next time if value is not result: self[key] = result if type(result) in (ConvertingDict, ConvertingList, ConvertingTuple): result.parent = self result.key = key return result def pop(self, idx=-1): value = list.pop(self, idx) result = self.configurator.convert(value) if value is not result: if type(result) in (ConvertingDict, ConvertingList, ConvertingTuple): result.parent = self return result class ConvertingTuple(tuple): """A converting tuple wrapper.""" def __getitem__(self, key): value = tuple.__getitem__(self, key) result = self.configurator.convert(value) if value is not result: if type(result) in (ConvertingDict, ConvertingList, ConvertingTuple): result.parent = self result.key = key return result class BaseConfigurator(object): """ The configurator base class which defines some useful defaults. """ CONVERT_PATTERN = re.compile(r'^(?P[a-z]+)://(?P.*)$') WORD_PATTERN = re.compile(r'^\s*(\w+)\s*') DOT_PATTERN = re.compile(r'^\.\s*(\w+)\s*') INDEX_PATTERN = re.compile(r'^\[\s*(\w+)\s*\]\s*') DIGIT_PATTERN = re.compile(r'^\d+$') value_converters = { 'ext' : 'ext_convert', 'cfg' : 'cfg_convert', } # We might want to use a different one, e.g. importlib importer = __import__ def __init__(self, config): self.config = ConvertingDict(config) self.config.configurator = self def resolve(self, s): """ Resolve strings to objects using standard import and attribute syntax. """ name = s.split('.') used = name.pop(0) found = self.importer(used) for frag in name: used += '.' + frag try: found = getattr(found, frag) except AttributeError: self.importer(used) found = getattr(found, frag) return found def ext_convert(self, value): """Default converter for the ext:// protocol.""" return self.resolve(value) def cfg_convert(self, value): """Default converter for the cfg:// protocol.""" rest = value m = self.WORD_PATTERN.match(rest) if m is None: raise ValueError("Unable to convert %r" % value) else: rest = rest[m.end():] d = self.config[m.groups()[0]] #print d, rest while rest: m = self.DOT_PATTERN.match(rest) if m: d = d[m.groups()[0]] else: m = self.INDEX_PATTERN.match(rest) if m: idx = m.groups()[0] if not self.DIGIT_PATTERN.match(idx): d = d[idx] else: try: n = int(idx) # try as number first (most likely) d = d[n] except TypeError: d = d[idx] if m: rest = rest[m.end():] else: raise ValueError('Unable to convert ' '%r at %r' % (value, rest)) #rest should be empty return d def convert(self, value): """ Convert values to an appropriate type. dicts, lists and tuples are replaced by their converting alternatives. Strings are checked to see if they have a conversion format and are converted if they do. """ if not isinstance(value, ConvertingDict) and isinstance(value, dict): value = ConvertingDict(value) value.configurator = self elif not isinstance(value, ConvertingList) and isinstance(value, list): value = ConvertingList(value) value.configurator = self elif not isinstance(value, ConvertingTuple) and\ isinstance(value, tuple): value = ConvertingTuple(value) value.configurator = self elif isinstance(value, str): m = self.CONVERT_PATTERN.match(value) if m: d = m.groupdict() prefix = d['prefix'] converter = self.value_converters.get(prefix, None) if converter: suffix = d['suffix'] converter = getattr(self, converter) value = converter(suffix) return value def configure_custom(self, config): """Configure an object with a user-supplied factory.""" c = config.pop('()') if not hasattr(c, '__call__'): c = self.resolve(c) props = config.pop('.', None) # Check for valid identifiers kwargs = dict([(k, config[k]) for k in config if valid_ident(k)]) result = c(**kwargs) if props: for name, value in props.items(): setattr(result, name, value) return result class DictConfigurator(BaseConfigurator): """ Configure logging using a dictionary-like object to describe the configuration. """ def configure(self): """Do the configuration.""" config = self.config incremental = config.pop('incremental', False) EMPTY_DICT = {} logging._acquireLock() try: if incremental: handlers = config.get('handlers', EMPTY_DICT) for name in handlers: if name not in logging._handlers: raise ValueError('No handler found with ' 'name %r' % name) else: try: handler = logging._handlers[name] handler_config = handlers[name] level = handler_config.get('level', None) if level: handler.setLevel(logging._checkLevel(level)) except Exception as e: raise ValueError('Unable to configure handler ' '%r: %s' % (name, e)) loggers = config.get('loggers', EMPTY_DICT) for name in loggers: try: self.configure_logger(name, loggers[name], True) except Exception as e: raise ValueError('Unable to configure logger ' '%r: %s' % (name, e)) root = config.get('root', None) if root: try: self.configure_root(root, True) except Exception as e: raise ValueError('Unable to configure root ' 'logger: %s' % e) else: disable_existing = config.pop('disable_existing_loggers', True) logging._handlers.clear() del logging._handlerList[:] # Do formatters first - they don't refer to anything else formatters = config.get('formatters', EMPTY_DICT) for name in formatters: try: formatters[name] = self.configure_formatter( formatters[name]) except Exception as e: raise ValueError('Unable to configure ' 'formatter %r: %s' % (name, e)) # Next, do filters - they don't refer to anything else, either filters = config.get('filters', EMPTY_DICT) for name in filters: try: filters[name] = self.configure_filter(filters[name]) except Exception as e: raise ValueError('Unable to configure ' 'filter %r: %s' % (name, e)) # Next, do handlers - they refer to formatters and filters # As handlers can refer to other handlers, sort the keys # to allow a deterministic order of configuration handlers = config.get('handlers', EMPTY_DICT) for name in sorted(handlers): try: handler = self.configure_handler(handlers[name]) handler.name = name handlers[name] = handler except Exception as e: raise ValueError('Unable to configure handler ' '%r: %s' % (name, e)) # Next, do loggers - they refer to handlers and filters #we don't want to lose the existing loggers, #since other threads may have pointers to them. #existing is set to contain all existing loggers, #and as we go through the new configuration we #remove any which are configured. At the end, #what's left in existing is the set of loggers #which were in the previous configuration but #which are not in the new configuration. root = logging.root existing = list(root.manager.loggerDict.keys()) #The list needs to be sorted so that we can #avoid disabling child loggers of explicitly #named loggers. With a sorted list it is easier #to find the child loggers. existing.sort() #We'll keep the list of existing loggers #which are children of named loggers here... child_loggers = [] #now set up the new ones... loggers = config.get('loggers', EMPTY_DICT) for name in loggers: if name in existing: i = existing.index(name) prefixed = name + "." pflen = len(prefixed) num_existing = len(existing) i = i + 1 # look at the entry after name while (i < num_existing) and\ (existing[i][:pflen] == prefixed): child_loggers.append(existing[i]) i = i + 1 existing.remove(name) try: self.configure_logger(name, loggers[name]) except Exception as e: raise ValueError('Unable to configure logger ' '%r: %s' % (name, e)) #Disable any old loggers. There's no point deleting #them as other threads may continue to hold references #and by disabling them, you stop them doing any logging. #However, don't disable children of named loggers, as that's #probably not what was intended by the user. for log in existing: logger = root.manager.loggerDict[log] if log in child_loggers: logger.level = logging.NOTSET logger.handlers = [] logger.propagate = True elif disable_existing: logger.disabled = True # And finally, do the root logger root = config.get('root', None) if root: try: self.configure_root(root) except Exception as e: raise ValueError('Unable to configure root ' 'logger: %s' % e) finally: logging._releaseLock() def configure_formatter(self, config): """Configure a formatter from a dictionary.""" if '()' in config: factory = config['()'] # for use in exception handler try: result = self.configure_custom(config) except TypeError as te: if "'format'" not in str(te): raise #Name of parameter changed from fmt to format. #Retry with old name. #This is so that code can be used with older Python versions #(e.g. by Django) config['fmt'] = config.pop('format') config['()'] = factory result = self.configure_custom(config) else: fmt = config.get('format', None) dfmt = config.get('datefmt', None) result = logging.Formatter(fmt, dfmt) return result def configure_filter(self, config): """Configure a filter from a dictionary.""" if '()' in config: result = self.configure_custom(config) else: name = config.get('name', '') result = logging.Filter(name) return result def add_filters(self, filterer, filters): """Add filters to a filterer from a list of names.""" for f in filters: try: filterer.addFilter(self.config['filters'][f]) except Exception as e: raise ValueError('Unable to add filter %r: %s' % (f, e)) def configure_handler(self, config): """Configure a handler from a dictionary.""" formatter = config.pop('formatter', None) if formatter: try: formatter = self.config['formatters'][formatter] except Exception as e: raise ValueError('Unable to set formatter ' '%r: %s' % (formatter, e)) level = config.pop('level', None) filters = config.pop('filters', None) if '()' in config: c = config.pop('()') if not hasattr(c, '__call__') and hasattr(types, 'ClassType') and type(c) != types.ClassType: c = self.resolve(c) factory = c else: klass = self.resolve(config.pop('class')) #Special case for handler which refers to another handler if issubclass(klass, logging.handlers.MemoryHandler) and\ 'target' in config: try: config['target'] = self.config['handlers'][config['target']] except Exception as e: raise ValueError('Unable to set target handler ' '%r: %s' % (config['target'], e)) factory = klass kwargs = dict([(k, config[k]) for k in config if valid_ident(k)]) try: result = factory(**kwargs) except TypeError as te: if "'stream'" not in str(te): raise #The argument name changed from strm to stream #Retry with old name. #This is so that code can be used with older Python versions #(e.g. by Django) kwargs['strm'] = kwargs.pop('stream') result = factory(**kwargs) if formatter: result.setFormatter(formatter) if level is not None: result.setLevel(logging._checkLevel(level)) if filters: self.add_filters(result, filters) return result def add_handlers(self, logger, handlers): """Add handlers to a logger from a list of names.""" for h in handlers: try: logger.addHandler(self.config['handlers'][h]) except Exception as e: raise ValueError('Unable to add handler %r: %s' % (h, e)) def common_logger_config(self, logger, config, incremental=False): """ Perform configuration which is common to root and non-root loggers. """ level = config.get('level', None) if level is not None: logger.setLevel(logging._checkLevel(level)) if not incremental: #Remove any existing handlers for h in logger.handlers[:]: logger.removeHandler(h) handlers = config.get('handlers', None) if handlers: self.add_handlers(logger, handlers) filters = config.get('filters', None) if filters: self.add_filters(logger, filters) def configure_logger(self, name, config, incremental=False): """Configure a non-root logger from a dictionary.""" logger = logging.getLogger(name) self.common_logger_config(logger, config, incremental) propagate = config.get('propagate', None) if propagate is not None: logger.propagate = propagate def configure_root(self, config, incremental=False): """Configure a root logger from a dictionary.""" root = logging.getLogger() self.common_logger_config(root, config, incremental) dictConfigClass = DictConfigurator def dictConfig(config): """Configure logging using a dictionary.""" dictConfigClass(config).configure() def listen(port=DEFAULT_LOGGING_CONFIG_PORT): """ Start up a socket server on the specified port, and listen for new configurations. These will be sent as a file suitable for processing by fileConfig(). Returns a Thread object on which you can call start() to start the server, and which you can join() when appropriate. To stop the server, call stopListening(). """ if not thread: raise NotImplementedError("listen() needs threading to work") class ConfigStreamHandler(StreamRequestHandler): """ Handler for a logging configuration request. It expects a completely new logging configuration and uses fileConfig to install it. """ def handle(self): """ Handle a request. Each request is expected to be a 4-byte length, packed using struct.pack(">L", n), followed by the config file. Uses fileConfig() to do the grunt work. """ import tempfile try: conn = self.connection chunk = conn.recv(4) if len(chunk) == 4: slen = struct.unpack(">L", chunk)[0] chunk = self.connection.recv(slen) while len(chunk) < slen: chunk = chunk + conn.recv(slen - len(chunk)) chunk = chunk.decode('utf-8') try: import json d =json.loads(chunk) assert isinstance(d, dict) dictConfig(d) except: #Apply new configuration. file = io.StringIO(chunk) try: fileConfig(file) except (KeyboardInterrupt, SystemExit): raise except: traceback.print_exc() if self.server.ready: self.server.ready.set() except socket.error as e: if not isinstance(e.args, tuple): raise else: errcode = e.args[0] if errcode != RESET_ERROR: raise class ConfigSocketReceiver(ThreadingTCPServer): """ A simple TCP socket-based logging config receiver. """ allow_reuse_address = 1 def __init__(self, host='localhost', port=DEFAULT_LOGGING_CONFIG_PORT, handler=None, ready=None): ThreadingTCPServer.__init__(self, (host, port), handler) logging._acquireLock() self.abort = 0 logging._releaseLock() self.timeout = 1 self.ready = ready def serve_until_stopped(self): import select abort = 0 while not abort: rd, wr, ex = select.select([self.socket.fileno()], [], [], self.timeout) if rd: self.handle_request() logging._acquireLock() abort = self.abort logging._releaseLock() class Server(threading.Thread): def __init__(self, rcvr, hdlr, port): super(Server, self).__init__() self.rcvr = rcvr self.hdlr = hdlr self.port = port self.ready = threading.Event() def run(self): server = self.rcvr(port=self.port, handler=self.hdlr, ready=self.ready) self.ready.set() global _listener logging._acquireLock() _listener = server logging._releaseLock() server.serve_until_stopped() return Server(ConfigSocketReceiver, ConfigStreamHandler, port) def stopListening(): """ Stop the listening server which was created with a call to listen(). """ global _listener if _listener: logging._acquireLock() _listener.abort = 1 _listener = None logging._releaseLock()