diff options
Diffstat (limited to 'synapse/logging')
| -rw-r--r-- | synapse/logging/_structured.py | 374 | ||||
| -rw-r--r-- | synapse/logging/_terse_json.py | 278 | ||||
| -rw-r--r-- | synapse/logging/context.py | 14 |
3 files changed, 665 insertions, 1 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" + ) diff --git a/synapse/logging/_terse_json.py b/synapse/logging/_terse_json.py new file mode 100644 index 0000000000..7f1e8f23fe --- /dev/null +++ b/synapse/logging/_terse_json.py @@ -0,0 +1,278 @@ +# -*- 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. + +""" +Log formatters that output terse JSON. +""" + +import sys +from collections import deque +from ipaddress import IPv4Address, IPv6Address, ip_address +from math import floor +from typing.io import TextIO + +import attr +from simplejson import dumps + +from twisted.application.internet import ClientService +from twisted.internet.endpoints import ( + HostnameEndpoint, + TCP4ClientEndpoint, + TCP6ClientEndpoint, +) +from twisted.internet.protocol import Factory, Protocol +from twisted.logger import FileLogObserver, Logger +from twisted.python.failure import Failure + + +def flatten_event(event: dict, metadata: dict, include_time: bool = False): + """ + Flatten a Twisted logging event to an dictionary capable of being sent + as a log event to a logging aggregation system. + + The format is vastly simplified and is not designed to be a "human readable + string" in the sense that traditional logs are. Instead, the structure is + optimised for searchability and filtering, with human-understandable log + keys. + + Args: + event (dict): The Twisted logging event we are flattening. + metadata (dict): Additional data to include with each log message. This + can be information like the server name. Since the target log + consumer does not know who we are other than by host IP, this + allows us to forward through static information. + include_time (bool): Should we include the `time` key? If False, the + event time is stripped from the event. + """ + new_event = {} + + # If it's a failure, make the new event's log_failure be the traceback text. + if "log_failure" in event: + new_event["log_failure"] = event["log_failure"].getTraceback() + + # If it's a warning, copy over a string representation of the warning. + if "warning" in event: + new_event["warning"] = str(event["warning"]) + + # Stdlib logging events have "log_text" as their human-readable portion, + # Twisted ones have "log_format". For now, include the log_format, so that + # context only given in the log format (e.g. what is being logged) is + # available. + if "log_text" in event: + new_event["log"] = event["log_text"] + else: + new_event["log"] = event["log_format"] + + # We want to include the timestamp when forwarding over the network, but + # exclude it when we are writing to stdout. This is because the log ingester + # (e.g. logstash, fluentd) can add its own timestamp. + if include_time: + new_event["time"] = round(event["log_time"], 2) + + # Convert the log level to a textual representation. + new_event["level"] = event["log_level"].name.upper() + + # Ignore these keys, and do not transfer them over to the new log object. + # They are either useless (isError), transferred manually above (log_time, + # log_level, etc), or contain Python objects which are not useful for output + # (log_logger, log_source). + keys_to_delete = [ + "isError", + "log_failure", + "log_format", + "log_level", + "log_logger", + "log_source", + "log_system", + "log_time", + "log_text", + "observer", + "warning", + ] + + # If it's from the Twisted legacy logger (twisted.python.log), it adds some + # more keys we want to purge. + if event.get("log_namespace") == "log_legacy": + keys_to_delete.extend(["message", "system", "time"]) + + # Rather than modify the dictionary in place, construct a new one with only + # the content we want. The original event should be considered 'frozen'. + for key in event.keys(): + + if key in keys_to_delete: + continue + + if isinstance(event[key], (str, int, bool, float)) or event[key] is None: + # If it's a plain type, include it as is. + new_event[key] = event[key] + else: + # If it's not one of those basic types, write out a string + # representation. This should probably be a warning in development, + # so that we are sure we are only outputting useful data. + new_event[key] = str(event[key]) + + # Add the metadata information to the event (e.g. the server_name). + new_event.update(metadata) + + return new_event + + +def TerseJSONToConsoleLogObserver(outFile: TextIO, metadata: dict) -> FileLogObserver: + """ + A log observer that formats events to a flattened JSON representation. + + Args: + outFile: The file object to write to. + metadata: Metadata to be added to each log object. + """ + + def formatEvent(_event: dict) -> str: + flattened = flatten_event(_event, metadata) + return dumps(flattened, ensure_ascii=False, separators=(",", ":")) + "\n" + + return FileLogObserver(outFile, formatEvent) + + +@attr.s +class TerseJSONToTCPLogObserver(object): + """ + An IObserver that writes JSON logs to a TCP target. + + Args: + hs (HomeServer): The Homeserver that is being logged for. + host: The host of the logging target. + port: The logging target's port. + metadata: Metadata to be added to each log entry. + """ + + hs = attr.ib() + host = attr.ib(type=str) + port = attr.ib(type=int) + metadata = attr.ib(type=dict) + maximum_buffer = attr.ib(type=int) + _buffer = attr.ib(default=attr.Factory(deque), type=deque) + _writer = attr.ib(default=None) + _logger = attr.ib(default=attr.Factory(Logger)) + + def start(self) -> None: + + # Connect without DNS lookups if it's a direct IP. + try: + ip = ip_address(self.host) + if isinstance(ip, IPv4Address): + endpoint = TCP4ClientEndpoint( + self.hs.get_reactor(), self.host, self.port + ) + elif isinstance(ip, IPv6Address): + endpoint = TCP6ClientEndpoint( + self.hs.get_reactor(), self.host, self.port + ) + except ValueError: + endpoint = HostnameEndpoint(self.hs.get_reactor(), self.host, self.port) + + factory = Factory.forProtocol(Protocol) + self._service = ClientService(endpoint, factory, clock=self.hs.get_reactor()) + self._service.startService() + + def _write_loop(self) -> None: + """ + Implement the write loop. + """ + if self._writer: + return + + self._writer = self._service.whenConnected() + + @self._writer.addBoth + def writer(r): + if isinstance(r, Failure): + r.printTraceback(file=sys.__stderr__) + self._writer = None + self.hs.get_reactor().callLater(1, self._write_loop) + return + + try: + for event in self._buffer: + r.transport.write( + dumps(event, ensure_ascii=False, separators=(",", ":")).encode( + "utf8" + ) + ) + r.transport.write(b"\n") + self._buffer.clear() + except Exception as e: + sys.__stderr__.write("Failed writing out logs with %s\n" % (str(e),)) + + self._writer = False + self.hs.get_reactor().callLater(1, self._write_loop) + + def _handle_pressure(self) -> None: + """ + Handle backpressure by shedding events. + + The buffer will, in this order, until the buffer is below the maximum: + - Shed DEBUG events + - Shed INFO events + - Shed the middle 50% of the events. + """ + if len(self._buffer) <= self.maximum_buffer: + return + + # Strip out DEBUGs + self._buffer = deque( + filter(lambda event: event["level"] != "DEBUG", self._buffer) + ) + + if len(self._buffer) <= self.maximum_buffer: + return + + # Strip out INFOs + self._buffer = deque( + filter(lambda event: event["level"] != "INFO", self._buffer) + ) + + if len(self._buffer) <= self.maximum_buffer: + return + + # Cut the middle entries out + buffer_split = floor(self.maximum_buffer / 2) + + old_buffer = self._buffer + self._buffer = deque() + + for i in range(buffer_split): + self._buffer.append(old_buffer.popleft()) + + end_buffer = [] + for i in range(buffer_split): + end_buffer.append(old_buffer.pop()) + + self._buffer.extend(reversed(end_buffer)) + + def __call__(self, event: dict) -> None: + flattened = flatten_event(event, self.metadata, include_time=True) + self._buffer.append(flattened) + + # Handle backpressure, if it exists. + try: + self._handle_pressure() + except Exception: + # If handling backpressure fails,clear the buffer and log the + # exception. + self._buffer.clear() + self._logger.failure("Failed clearing backpressure") + + # Try and write immediately. + self._write_loop() diff --git a/synapse/logging/context.py b/synapse/logging/context.py index b456c31f70..63379bfb93 100644 --- a/synapse/logging/context.py +++ b/synapse/logging/context.py @@ -25,6 +25,7 @@ See doc/log_contexts.rst for details on how this works. import logging import threading import types +from typing import Any, List from twisted.internet import defer, threads @@ -194,7 +195,7 @@ class LoggingContext(object): class Sentinel(object): """Sentinel to represent the root context""" - __slots__ = [] + __slots__ = [] # type: List[Any] def __str__(self): return "sentinel" @@ -202,6 +203,10 @@ class LoggingContext(object): def copy_to(self, record): pass + def copy_to_twisted_log_entry(self, record): + record["request"] = None + record["scope"] = None + def start(self): pass @@ -330,6 +335,13 @@ class LoggingContext(object): # we also track the current scope: record.scope = self.scope + def copy_to_twisted_log_entry(self, record): + """ + Copy logging fields from this context to a Twisted log record. + """ + record["request"] = self.request + record["scope"] = self.scope + def start(self): if get_thread_id() != self.main_thread: logger.warning("Started logcontext %s on different thread", self) |