On January 1, 2020 this library will no longer support Python 2 on the latest released version. Previously released library versions will continue to be available. For more information please visit Python 2 support on Google Cloud.

Source code for google.cloud.logging.handlers.app_engine

# Copyright 2016 Google LLC All Rights Reserved.
#
# 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,
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# See the License for the specific language governing permissions and
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"""Logging handler for App Engine Flexible

Sends logs to the Stackdriver Logging API with the appropriate resource
and labels for App Engine logs.
"""

import logging
import os

from google.cloud.logging.handlers._helpers import get_trace_id
from google.cloud.logging.handlers.transports import BackgroundThreadTransport
from google.cloud.logging.resource import Resource

_DEFAULT_GAE_LOGGER_NAME = "app"

_GAE_PROJECT_ENV_FLEX = "GCLOUD_PROJECT"
_GAE_PROJECT_ENV_STANDARD = "GOOGLE_CLOUD_PROJECT"
_GAE_SERVICE_ENV = "GAE_SERVICE"
_GAE_VERSION_ENV = "GAE_VERSION"

_TRACE_ID_LABEL = "appengine.googleapis.com/trace_id"


[docs]class AppEngineHandler(logging.StreamHandler): """A logging handler that sends App Engine-formatted logs to Stackdriver. :type client: :class:`~google.cloud.logging.client.Client` :param client: The authenticated Google Cloud Logging client for this handler to use. :type transport: :class:`type` :param transport: The transport class. It should be a subclass of :class:`.Transport`. If unspecified, :class:`.BackgroundThreadTransport` will be used. :type stream: file-like object :param stream: (optional) stream to be used by the handler. """ def __init__( self, client, name=_DEFAULT_GAE_LOGGER_NAME, transport=BackgroundThreadTransport, stream=None, ): super(AppEngineHandler, self).__init__(stream) self.name = name self.client = client self.transport = transport(client, name) self.project_id = os.environ.get( _GAE_PROJECT_ENV_FLEX, os.environ.get(_GAE_PROJECT_ENV_STANDARD, "") ) self.module_id = os.environ.get(_GAE_SERVICE_ENV, "") self.version_id = os.environ.get(_GAE_VERSION_ENV, "") self.resource = self.get_gae_resource()
[docs] def get_gae_resource(self): """Return the GAE resource using the environment variables. :rtype: :class:`~google.cloud.logging.resource.Resource` :returns: Monitored resource for GAE. """ gae_resource = Resource( type="gae_app", labels={ "project_id": self.project_id, "module_id": self.module_id, "version_id": self.version_id, }, ) return gae_resource
[docs] def get_gae_labels(self): """Return the labels for GAE app. If the trace ID can be detected, it will be included as a label. Currently, no other labels are included. :rtype: dict :returns: Labels for GAE app. """ gae_labels = {} trace_id = get_trace_id() if trace_id is not None: gae_labels[_TRACE_ID_LABEL] = trace_id return gae_labels
[docs] def emit(self, record): """Actually log the specified logging record. Overrides the default emit behavior of ``StreamHandler``. See https://docs.python.org/2/library/logging.html#handler-objects :type record: :class:`logging.LogRecord` :param record: The record to be logged. """ message = super(AppEngineHandler, self).format(record) gae_labels = self.get_gae_labels() trace_id = ( "projects/%s/traces/%s" % (self.project_id, gae_labels[_TRACE_ID_LABEL]) if _TRACE_ID_LABEL in gae_labels else None ) self.transport.send( record, message, resource=self.resource, labels=gae_labels, trace=trace_id )