django/docs/howto/error-reporting.txt

Error reporting via email
=========================

When you're running a public site you should always turn off the
:setting:`DEBUG` setting. That will make your server run much faster, and will
also prevent malicious users from seeing details of your application that can be
revealed by the error pages.

However, running with :setting:`DEBUG` set to ``False`` means you'll never see
errors generated by your site -- everyone will just see your public error pages.
You need to keep track of errors that occur in deployed sites, so Django can be
configured to email you details of those errors.

Server errors
-------------

When :setting:`DEBUG` is ``False``, Django will email the users listed in the
:setting:`ADMINS` setting whenever your code raises an unhandled exception and
results in an internal server error (HTTP status code 500). This gives the
administrators immediate notification of any errors. The :setting:`ADMINS` will
get a description of the error, a complete Python traceback, and details about
the HTTP request that caused the error.

.. note::

   In order to send email, Django requires a few settings telling it
   how to connect to your mail server. At the very least, you'll need
   to specify :setting:`EMAIL_HOST` and possibly
   :setting:`EMAIL_HOST_USER` and :setting:`EMAIL_HOST_PASSWORD`,
   though other settings may be also required depending on your mail
   server's configuration. Consult :doc:`the Django settings
   documentation </ref/settings>` for a full list of email-related
   settings.

By default, Django will send email from root@localhost. However, some mail
providers reject all email from this address. To use a different sender
address, modify the :setting:`SERVER_EMAIL` setting.

To disable this behavior, just remove all entries from the :setting:`ADMINS`
setting.

.. seealso::

   .. versionadded:: 1.3

   Server error emails are sent using the logging framework, so you can
   customize this behavior by :doc:`customizing your logging configuration
   </topics/logging>`.

404 errors
----------

Django can also be configured to email errors about broken links (404 "page
not found" errors). Django sends emails about 404 errors when:

    * :setting:`DEBUG` is ``False``

    * :setting:`SEND_BROKEN_LINK_EMAILS` is ``True``

    * Your :setting:`MIDDLEWARE_CLASSES` setting includes ``CommonMiddleware``
      (which it does by default).

If those conditions are met, Django will email the users listed in the
:setting:`MANAGERS` setting whenever your code raises a 404 and the request has
a referer. (It doesn't bother to email for 404s that don't have a referer --
those are usually just people typing in broken URLs or broken Web 'bots).

You can tell Django to stop reporting particular 404s by tweaking the
:setting:`IGNORABLE_404_URLS` setting. It should be a tuple of compiled
regular expression objects. For example::

    import re
    IGNORABLE_404_URLS = (
        re.compile(r'\.(php|cgi)$'),
        re.compile(r'^/phpmyadmin/'),
    )

In this example, a 404 to any URL ending with ``.php`` or ``.cgi`` will *not* be
reported. Neither will any URL starting with ``/phpmyadmin/``.

The following example shows how to exclude some conventional URLs that browsers and
crawlers often request::

    import re
    IGNORABLE_404_URLS = (
        re.compile(r'^/apple-touch-icon.*\.png$'),
        re.compile(r'^/favicon\.ico$),
        re.compile(r'^/robots\.txt$),
    )

(Note that these are regular expressions, so we put a backslash in front of
periods to escape them.)

The best way to disable this behavior is to set
:setting:`SEND_BROKEN_LINK_EMAILS` to ``False``.

.. seealso::

    You can also set up custom error reporting by writing a custom piece of
    :ref:`exception middleware <exception-middleware>`. If you do write custom
    error handling, it's a good idea to emulate Django's built-in error handling
    and only report/log errors if :setting:`DEBUG` is ``False``.

.. seealso::

   .. versionadded:: 1.3

   404 errors are logged using the logging framework. By default, these log
   records are ignored, but you can use them for error reporting by writing a
   handler and :doc:`configuring logging </topics/logging>` appropriately.

.. seealso::

   .. versionchanged:: 1.4

   Previously, two settings were used to control which URLs not to report:
   :setting:`IGNORABLE_404_STARTS` and :setting:`IGNORABLE_404_ENDS`. They
   were replaced by :setting:`IGNORABLE_404_URLS`.