logging.py

#  BSD 3-Clause License
#
#  Copyright (c) 2012, the Sentry Team, see AUTHORS for more details
#  Copyright (c) 2019, Elasticsearch BV
#  All rights reserved.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions are met:
#
#  * Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
#
#  * Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
#  * Neither the name of the copyright holder nor the names of its
#    contributors may be used to endorse or promote products derived from
#    this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
#  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
#  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
#  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
#  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
#  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
#  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE


from __future__ import absolute_import

import logging
import sys
import traceback
import warnings

import wrapt

from elasticapm import get_client
from elasticapm.base import Client
from elasticapm.traces import execution_context
from elasticapm.utils.stacks import iter_stack_frames


class LoggingHandler(logging.Handler):
    def __init__(self, *args, **kwargs) -> None:
        warnings.warn(
            "The LoggingHandler is deprecated and will be removed in v7.0 of "
            "the agent. Please use `log_ecs_reformatting` and ship the logs "
            "with Elastic Agent or Filebeat instead. "
            "https://www.elastic.co/guide/en/apm/agent/python/current/logs.html",
            DeprecationWarning,
        )
        self.client = None
        if "client" in kwargs:
            self.client = kwargs.pop("client")
        elif len(args) > 0:
            arg = args[0]
            if isinstance(arg, Client):
                self.client = arg

        if not self.client:
            client_cls = kwargs.pop("client_cls", None)
            if client_cls:
                self.client = client_cls(*args, **kwargs)
            else:
                warnings.warn(
                    "LoggingHandler requires a Client instance. No Client was received.",
                    DeprecationWarning,
                )
                self.client = Client(*args, **kwargs)
        logging.Handler.__init__(self, level=kwargs.get("level", logging.NOTSET))

    def emit(self, record):
        self.format(record)

        # Avoid typical config issues by overriding loggers behavior
        if record.name.startswith(("elasticapm.errors",)):
            sys.stderr.write(record.getMessage() + "\n")
            return

        try:
            return self._emit(record)
        except Exception:
            sys.stderr.write("Top level ElasticAPM exception caught - failed creating log record.\n")
            sys.stderr.write(record.getMessage() + "\n")
            sys.stderr.write(traceback.format_exc() + "\n")

            try:
                self.client.capture("Exception")
            except Exception:
                pass

    def _emit(self, record, **kwargs):
        data = {}

        for k, v in record.__dict__.items():
            if "." not in k and k not in ("culprit",):
                continue
            data[k] = v

        stack = getattr(record, "stack", None)
        if stack is True:
            stack = iter_stack_frames(config=self.client.config)

        if stack:
            frames = []
            started = False
            last_mod = ""
            for item in stack:
                if isinstance(item, (list, tuple)):
                    frame, lineno = item
                else:
                    frame, lineno = item, item.f_lineno

                if not started:
                    f_globals = getattr(frame, "f_globals", {})
                    module_name = f_globals.get("__name__", "")
                    if last_mod.startswith("logging") and not module_name.startswith("logging"):
                        started = True
                    else:
                        last_mod = module_name
                        continue
                frames.append((frame, lineno))
            stack = frames

        custom = getattr(record, "data", {})
        # Add in all of the data from the record that we aren't already capturing
        for k in record.__dict__.keys():
            if k in (
                "stack",
                "name",
                "args",
                "msg",
                "levelno",
                "exc_text",
                "exc_info",
                "data",
                "created",
                "levelname",
                "msecs",
                "relativeCreated",
            ):
                continue
            if k.startswith("_"):
                continue
            custom[k] = record.__dict__[k]

        # If there's no exception being processed,
        # exc_info may be a 3-tuple of None
        # http://docs.python.org/library/sys.html#sys.exc_info
        if record.exc_info and all(record.exc_info):
            handler = self.client.get_handler("elasticapm.events.Exception")
            exception = handler.capture(self.client, exc_info=record.exc_info)
        else:
            exception = None

        return self.client.capture(
            "Message",
            param_message={"message": str(record.msg), "params": record.args},
            stack=stack,
            custom=custom,
            exception=exception,
            level=record.levelno,
            logger_name=record.name,
            **kwargs,
        )


class LoggingFilter(logging.Filter):
    """
    This filter doesn't actually do any "filtering" -- rather, it just adds
    three new attributes to any "filtered" LogRecord objects:

    * elasticapm_transaction_id
    * elasticapm_trace_id
    * elasticapm_span_id
    * elasticapm_service_name

    These attributes can then be incorporated into your handlers and formatters,
    so that you can tie log messages to transactions in elasticsearch.

    This filter also adds these fields to a dictionary attribute,
    `elasticapm_labels`, using the official tracing fields names as documented
    here: https://www.elastic.co/guide/en/ecs/current/ecs-tracing.html

    Note that if you're using Python 3.2+, by default we will add a
    LogRecordFactory to your root logger which will add these attributes
    automatically.
    """

    def __init__(self, name=""):
        super().__init__(name=name)
        warnings.warn(
            "The LoggingFilter is deprecated and will be removed in v7.0 of "
            "the agent. On Python 3.2+, by default we add a LogRecordFactory to "
            "your root logger automatically"
            "https://www.elastic.co/guide/en/apm/agent/python/current/logs.html",
            DeprecationWarning,
        )

    def filter(self, record):
        """
        Add elasticapm attributes to `record`.
        """
        _add_attributes_to_log_record(record)
        return True


@wrapt.decorator
def log_record_factory(wrapped, instance, args, kwargs):
    """
    Decorator, designed to wrap the python log record factory (fetched by
    logging.getLogRecordFactory), adding the same custom attributes as in
    the LoggingFilter provided above.

    :return:
        LogRecord object, with custom attributes for APM tracing fields
    """
    record = wrapped(*args, **kwargs)
    return _add_attributes_to_log_record(record)


def _add_attributes_to_log_record(record):
    """
    Add custom attributes for APM tracing fields to a LogRecord object

    :param record: LogRecord object
    :return: Updated LogRecord object with new APM tracing fields
    """
    transaction = execution_context.get_transaction()

    transaction_id = transaction.id if transaction else None
    record.elasticapm_transaction_id = transaction_id

    trace_id = transaction.trace_parent.trace_id if transaction and transaction.trace_parent else None
    record.elasticapm_trace_id = trace_id

    span = execution_context.get_span()
    span_id = span.id if span else None
    record.elasticapm_span_id = span_id

    client = get_client()
    service_name = client.config.service_name if client else None
    record.elasticapm_service_name = service_name

    service_environment = client.config.environment if client else None
    record.elasticapm_service_environment = service_environment

    record.elasticapm_labels = {
        "transaction.id": transaction_id,
        "trace.id": trace_id,
        "span.id": span_id,
        "service.name": service_name,
        "service.environment": service_environment,
    }

    return record


class Formatter(logging.Formatter):
    """
    Custom formatter to automatically append the elasticapm format string,
    as well as ensure that LogRecord objects actually have the required fields
    (so as to avoid errors which could occur for logs before we override the
    LogRecordFactory):

        formatstring = "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
        formatstring = formatstring + " | elasticapm " \
                                      "transaction.id=%(elasticapm_transaction_id)s " \
                                      "trace.id=%(elasticapm_trace_id)s " \
                                      "span.id=%(elasticapm_span_id)s"
    """

    def __init__(self, fmt=None, datefmt=None, style="%") -> None:
        if fmt is None:
            fmt = "%(message)s"
        fmt = (
            fmt + " | elasticapm "
            "transaction.id=%(elasticapm_transaction_id)s "
            "trace.id=%(elasticapm_trace_id)s "
            "span.id=%(elasticapm_span_id)s"
        )
        super(Formatter, self).__init__(fmt=fmt, datefmt=datefmt, style=style)

    def format(self, record):
        if not hasattr(record, "elasticapm_transaction_id"):
            record.elasticapm_transaction_id = None
            record.elasticapm_trace_id = None
            record.elasticapm_span_id = None
            record.elasticapm_service_name = None
            record.elasticapm_service_environment = None
        return super(Formatter, self).format(record=record)

    def formatTime(self, record, datefmt=None):
        if not hasattr(record, "elasticapm_transaction_id"):
            record.elasticapm_transaction_id = None
            record.elasticapm_trace_id = None
            record.elasticapm_span_id = None
            record.elasticapm_service_name = None
            record.elasticapm_service_environment = None
        return super(Formatter, self).formatTime(record=record, datefmt=datefmt)