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Diffstat (limited to 'synapse/logging/_structured.py')
| -rw-r--r-- | synapse/logging/_structured.py | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/synapse/logging/_structured.py b/synapse/logging/_structured.py new file mode 100644 index 0000000000..0367d6dfc4 --- /dev/null +++ b/synapse/logging/_structured.py @@ -0,0 +1,374 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 The Matrix.org Foundation C.I.C. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +import logging +import os.path +import sys +import typing +import warnings + +import attr +from constantly import NamedConstant, Names, ValueConstant, Values +from zope.interface import implementer + +from twisted.logger import ( + FileLogObserver, + FilteringLogObserver, + ILogObserver, + LogBeginner, + Logger, + LogLevel, + LogLevelFilterPredicate, + LogPublisher, + eventAsText, + globalLogBeginner, + jsonFileLogObserver, +) + +from synapse.config._base import ConfigError +from synapse.logging._terse_json import ( + TerseJSONToConsoleLogObserver, + TerseJSONToTCPLogObserver, +) +from synapse.logging.context import LoggingContext + + +def stdlib_log_level_to_twisted(level: str) -> LogLevel: + """ + Convert a stdlib log level to Twisted's log level. + """ + lvl = level.lower().replace("warning", "warn") + return LogLevel.levelWithName(lvl) + + +@attr.s +@implementer(ILogObserver) +class LogContextObserver(object): + """ + An ILogObserver which adds Synapse-specific log context information. + + Attributes: + observer (ILogObserver): The target parent observer. + """ + + observer = attr.ib() + + def __call__(self, event: dict) -> None: + """ + Consume a log event and emit it to the parent observer after filtering + and adding log context information. + + Args: + event (dict) + """ + # Filter out some useless events that Twisted outputs + if "log_text" in event: + if event["log_text"].startswith("DNSDatagramProtocol starting on "): + return + + if event["log_text"].startswith("(UDP Port "): + return + + if event["log_text"].startswith("Timing out client") or event[ + "log_format" + ].startswith("Timing out client"): + return + + context = LoggingContext.current_context() + + # Copy the context information to the log event. + if context is not None: + context.copy_to_twisted_log_entry(event) + else: + # If there's no logging context, not even the root one, we might be + # starting up or it might be from non-Synapse code. Log it as if it + # came from the root logger. + event["request"] = None + event["scope"] = None + + self.observer(event) + + +class PythonStdlibToTwistedLogger(logging.Handler): + """ + Transform a Python stdlib log message into a Twisted one. + """ + + def __init__(self, observer, *args, **kwargs): + """ + Args: + observer (ILogObserver): A Twisted logging observer. + *args, **kwargs: Args/kwargs to be passed to logging.Handler. + """ + self.observer = observer + super().__init__(*args, **kwargs) + + def emit(self, record: logging.LogRecord) -> None: + """ + Emit a record to Twisted's observer. + + Args: + record (logging.LogRecord) + """ + + self.observer( + { + "log_time": record.created, + "log_text": record.getMessage(), + "log_format": "{log_text}", + "log_namespace": record.name, + "log_level": stdlib_log_level_to_twisted(record.levelname), + } + ) + + +def SynapseFileLogObserver(outFile: typing.io.TextIO) -> FileLogObserver: + """ + A log observer that formats events like the traditional log formatter and + sends them to `outFile`. + + Args: + outFile (file object): The file object to write to. + """ + + def formatEvent(_event: dict) -> str: + event = dict(_event) + event["log_level"] = event["log_level"].name.upper() + event["log_format"] = "- {log_namespace} - {log_level} - {request} - " + ( + event.get("log_format", "{log_text}") or "{log_text}" + ) + return eventAsText(event, includeSystem=False) + "\n" + + return FileLogObserver(outFile, formatEvent) + + +class DrainType(Names): + CONSOLE = NamedConstant() + CONSOLE_JSON = NamedConstant() + CONSOLE_JSON_TERSE = NamedConstant() + FILE = NamedConstant() + FILE_JSON = NamedConstant() + NETWORK_JSON_TERSE = NamedConstant() + + +class OutputPipeType(Values): + stdout = ValueConstant(sys.__stdout__) + stderr = ValueConstant(sys.__stderr__) + + +@attr.s +class DrainConfiguration(object): + name = attr.ib() + type = attr.ib() + location = attr.ib() + options = attr.ib(default=None) + + +@attr.s +class NetworkJSONTerseOptions(object): + maximum_buffer = attr.ib(type=int) + + +DEFAULT_LOGGERS = {"synapse": {"level": "INFO"}} + + +def parse_drain_configs( + drains: dict +) -> typing.Generator[DrainConfiguration, None, None]: + """ + Parse the drain configurations. + + Args: + drains (dict): A list of drain configurations. + + Yields: + DrainConfiguration instances. + + Raises: + ConfigError: If any of the drain configuration items are invalid. + """ + for name, config in drains.items(): + if "type" not in config: + raise ConfigError("Logging drains require a 'type' key.") + + try: + logging_type = DrainType.lookupByName(config["type"].upper()) + except ValueError: + raise ConfigError( + "%s is not a known logging drain type." % (config["type"],) + ) + + if logging_type in [ + DrainType.CONSOLE, + DrainType.CONSOLE_JSON, + DrainType.CONSOLE_JSON_TERSE, + ]: + location = config.get("location") + if location is None or location not in ["stdout", "stderr"]: + raise ConfigError( + ( + "The %s drain needs the 'location' key set to " + "either 'stdout' or 'stderr'." + ) + % (logging_type,) + ) + + pipe = OutputPipeType.lookupByName(location).value + + yield DrainConfiguration(name=name, type=logging_type, location=pipe) + + elif logging_type in [DrainType.FILE, DrainType.FILE_JSON]: + if "location" not in config: + raise ConfigError( + "The %s drain needs the 'location' key set." % (logging_type,) + ) + + location = config.get("location") + if os.path.abspath(location) != location: + raise ConfigError( + "File paths need to be absolute, '%s' is a relative path" + % (location,) + ) + yield DrainConfiguration(name=name, type=logging_type, location=location) + + elif logging_type in [DrainType.NETWORK_JSON_TERSE]: + host = config.get("host") + port = config.get("port") + maximum_buffer = config.get("maximum_buffer", 1000) + yield DrainConfiguration( + name=name, + type=logging_type, + location=(host, port), + options=NetworkJSONTerseOptions(maximum_buffer=maximum_buffer), + ) + + else: + raise ConfigError( + "The %s drain type is currently not implemented." + % (config["type"].upper(),) + ) + + +def setup_structured_logging( + hs, + config, + log_config: dict, + logBeginner: LogBeginner = globalLogBeginner, + redirect_stdlib_logging: bool = True, +) -> LogPublisher: + """ + Set up Twisted's structured logging system. + + Args: + hs: The homeserver to use. + config (HomeserverConfig): The configuration of the Synapse homeserver. + log_config (dict): The log configuration to use. + """ + if config.no_redirect_stdio: + raise ConfigError( + "no_redirect_stdio cannot be defined using structured logging." + ) + + logger = Logger() + + if "drains" not in log_config: + raise ConfigError("The logging configuration requires a list of drains.") + + observers = [] + + for observer in parse_drain_configs(log_config["drains"]): + # Pipe drains + if observer.type == DrainType.CONSOLE: + logger.debug( + "Starting up the {name} console logger drain", name=observer.name + ) + observers.append(SynapseFileLogObserver(observer.location)) + elif observer.type == DrainType.CONSOLE_JSON: + logger.debug( + "Starting up the {name} JSON console logger drain", name=observer.name + ) + observers.append(jsonFileLogObserver(observer.location)) + elif observer.type == DrainType.CONSOLE_JSON_TERSE: + logger.debug( + "Starting up the {name} terse JSON console logger drain", + name=observer.name, + ) + observers.append( + TerseJSONToConsoleLogObserver(observer.location, metadata={}) + ) + + # File drains + elif observer.type == DrainType.FILE: + logger.debug("Starting up the {name} file logger drain", name=observer.name) + log_file = open(observer.location, "at", buffering=1, encoding="utf8") + observers.append(SynapseFileLogObserver(log_file)) + elif observer.type == DrainType.FILE_JSON: + logger.debug( + "Starting up the {name} JSON file logger drain", name=observer.name + ) + log_file = open(observer.location, "at", buffering=1, encoding="utf8") + observers.append(jsonFileLogObserver(log_file)) + + elif observer.type == DrainType.NETWORK_JSON_TERSE: + metadata = {"server_name": hs.config.server_name} + log_observer = TerseJSONToTCPLogObserver( + hs=hs, + host=observer.location[0], + port=observer.location[1], + metadata=metadata, + maximum_buffer=observer.options.maximum_buffer, + ) + log_observer.start() + observers.append(log_observer) + else: + # We should never get here, but, just in case, throw an error. + raise ConfigError("%s drain type cannot be configured" % (observer.type,)) + + publisher = LogPublisher(*observers) + log_filter = LogLevelFilterPredicate() + + for namespace, namespace_config in log_config.get( + "loggers", DEFAULT_LOGGERS + ).items(): + # Set the log level for twisted.logger.Logger namespaces + log_filter.setLogLevelForNamespace( + namespace, + stdlib_log_level_to_twisted(namespace_config.get("level", "INFO")), + ) + + # Also set the log levels for the stdlib logger namespaces, to prevent + # them getting to PythonStdlibToTwistedLogger and having to be formatted + if "level" in namespace_config: + logging.getLogger(namespace).setLevel(namespace_config.get("level")) + + f = FilteringLogObserver(publisher, [log_filter]) + lco = LogContextObserver(f) + + if redirect_stdlib_logging: + stuff_into_twisted = PythonStdlibToTwistedLogger(lco) + stdliblogger = logging.getLogger() + stdliblogger.addHandler(stuff_into_twisted) + + # Always redirect standard I/O, otherwise other logging outputs might miss + # it. + logBeginner.beginLoggingTo([lco], redirectStandardIO=True) + + return publisher + + +def reload_structured_logging(*args, log_config=None) -> None: + warnings.warn( + "Currently the structured logging system can not be reloaded, doing nothing" + ) |