timeline_django 0.0.3

Insert Django database queries in to a Timeline

timeline_django inserts actions in to a Timeline (http://pypi.python.org/pypi/timeline/) for Django db queries, and other events in Django. This is very useful for obtaining a holistic view of the blocking work and callouts involved in an individual Django request.

The usual pattern is to use this with python-oops - this README assumes you already have WSGI based OOPS reporting configured for your Django application.

WSGI

Running under wsgi is assumed (as mod_python is deprecated, and the dev and test servers in 1.4 and above are wsgi based. Some assembly may be required to run in a non-WSGI environment.

There are three necessary steps to configure timeline-django.

WSGI middleware

Put this in your WSGI application somewhere after your Django app definition but before the oops_wsgi wrapper is applied:

from timeline_django.wsgi import make_app as timeline_django_make_app
from timeline.wsgi import make_app as timeline_make_app
application = timeline_django_make_app(application)
application = timeline_make_app(application)

The first wrapper exposes the WSGI environ to Django code that runs without a request context - such as Django hooks which is where we catch ORM events.

The second wrapper injects a Timeline object into the WSGI environment.

Hook into Django events

Put this anywhere where it will run exactly once (e.g. in your WSGI application definition):

from timeline_django import setup
setup.setup_for_requests()

Redaction

Finally, you need to ensure that the content of queries that can leak security or personal information are redacted: this prevents session hijacking and privilege escalation attacks, making it safer for non-admin staff such as developers to see your timeline data:

import oops_timeline
import timeline_django.filters
oops_timeline.install_hooks(oops_config)
timeline_django.filters.install_hooks(oops_config)

The oops_timeline hook copies the timeline from the WSGI environ to the OOPS report, and the second one installs Django specific redaction filters that operate on the copied timeline - the ordering is important. The current filters provided by timeline_django are:

* ``session`` table to prevent session hijacking
* ``user`` table to prevent password disclosure

If your Django site uses other sensitive tables (e.g. alternative authentication modules) you should arrange to filter them as well. See timeline_django.filters for example code.

If you are not using timeline with python-oops you will need to arrange redaction for whatever timeline capture/view system you are using.

Non-WSGI environments

If you are running in other environments you need to do some of these steps yourself. First you need to pick a point to create a new Timeline object. This needs to correspond to the start of an timeline that you want to capture. That may be at the start of a script, or it may be in response to some other event.

Once you have created the Timeline you need to store it somewhere it can be accessed when needed. That may be in a variable, or it may be in thread-local storage if you will have multiple threads handling separate timelines. Once you have the Timline stored you need a function that will return it. That function will be your timeline_factory. It should take no arguments and return a Timeline object, or None if there is no applicable Timeline when it is called.

Once you have that method then you can call timeline_django’s setup_for_requests method:

from timeline_django.setup import setup_for_requests

setup_for_requests(timeline_factory=timeline_factory)

where timeline_factory is the function you created above. That will set up the hooks necessary to have an action recorded in your timeline when there is a DB query, or one of the other Django events that timeline_django supports.

Copyright (c) 2012, Canonical Ltd

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, version 3 only.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. GNU Lesser General Public License version 3 (see the file LICENSE).