============== pyramid_exclog ============== Overview ======== A package which logs Pyramid application exception (error) information to a standard Python :term:`logger`. This add-on is most useful when used in production applications, because the logger can be configured to log to a file, to UNIX syslog, to the Windows Event Log, or even to email. .. warning:: This package will only work with Pyramid 1.5 and better. Installation ============ Stable release -------------- To install pyramid_exclog, run this command in your terminal: .. code-block:: console $ pip install pyramid_exclog If you don't have `pip`_ installed, this `Python installation guide`_ can guide you through the process. .. _pip: https://pip.pypa.io .. _Python installation guide: https://docs.python-guide.org/en/latest/starting/installation/ From sources ------------ The sources for pyramid_exclog can be downloaded from the `Github repo`_. .. code-block:: console $ git clone https://github.com/Pylons/pyramid_exclog.git Once you have a copy of the source, you can install it with: .. code-block:: console $ pip install -e . .. _Github repo: https://github.com/Pylons/pyramid_exclog Setup ===== Once ``pyramid_exclog`` is installed, you must use the ``config.include`` mechanism to include it into your Pyramid project's configuration. In your Pyramid project's ``__init__.py``: .. code-block:: python :linenos: config = Configurator(...) config.include('pyramid_exclog') Alternately you can use the ``pyramid.includes`` configuration value in your ``.ini`` file: .. code-block:: ini :linenos: [app:myapp] pyramid.includes = pyramid_exclog Using ===== When this add-on is included into your Pyramid application, whenever a request to your application causes an exception to be raised, the add-on will send the URL that caused the exception, the exception type, and its related traceback information to a standard Python :term:`logger` named ``exc_logger``. You can use the logging configuration in your Pyramid application's ``.ini`` file to add a logger named ``exc_logger``. This logger should be hooked up a particular logging handler, which will allow you to use the standard Python logging machinery to send your exceptions to a file, to syslog, or to an email address. It's not generally useful to add exception logger configuration to a ``development.ini`` file, because typically exceptions are displayed in the interactive debugger and to the console which started the application, and you really don't care much about actually *logging* the exception information. However, it's very appropriate to add exception logger configuration to a ``production.ini`` file. The following logging configuration statements are in the *default* ``production.ini`` file generated by all Pyramid scaffolding: .. code-block:: ini :linenos: # Begin logging configuration [loggers] keys = root, myapp [handlers] keys = console [formatters] keys = generic [logger_root] level = WARN handlers = console [logger_myapp] level = WARN handlers = qualname = myapp [handler_console] class = StreamHandler args = (sys.stderr,) level = NOTSET formatter = generic [formatter_generic] format = %(asctime)s %(levelname)-5.5s [%(name)s][%(threadName)s] %(message)s # End logging configuration The standard logging configuration of the ``production.ini`` of a scaffolded Pyramid application does not name a logger named ``exc_logger``. Therefore, to start making use of ``pyramid_exclog``, you'll have to add an ``exc_logger`` logger to the configuration. To do so: 1) Append ``, exc_logger`` to the ``keys`` value of the ``[loggers]`` section, 2) Append ``, exc_handler`` to the ``keys`` value of the ``[handlers]`` section. 3) Append ``, exc_formatter`` to the ``keys`` value of the ``[formatters]`` section. 4) Add a section named ``[logger_exc_logger]`` with logger information related to the new exception logger. 5) Add a section named ``[handler_exc_handler]`` with handler information related to the new exception logger. In our example, it will have configuration that tells it to log to a file in the same directory as the ``.ini`` file named ``exceptions.log``. 6) Add a section named ``[formatter_exc_formatter]`` with message formatting information related to the messages sent to the ``exc_handler`` handler. By default we'll send only the time and the message. The resulting configuration will look like this: .. code-block:: ini :linenos: # Begin logging configuration [loggers] keys = root, myapp, exc_logger [handlers] keys = console, exc_handler [formatters] keys = generic, exc_formatter [logger_root] level = WARN handlers = console [logger_myapp] level = WARN handlers = qualname = myapp [logger_exc_logger] level = ERROR handlers = exc_handler qualname = exc_logger [handler_console] class = StreamHandler args = (sys.stderr,) level = NOTSET formatter = generic [handler_exc_handler] class = FileHandler args = ('%(here)s/exceptions.log',) level = ERROR formatter = exc_formatter [formatter_generic] format = %(asctime)s %(levelname)-5.5s [%(name)s][%(threadName)s] %(message)s [formatter_exc_formatter] format = %(asctime)s %(message)s # End logging configuration Once you've changed your logging configuration as per the above, and you restart your Pyramid application, all exceptions will be logged to a file named ``exceptions.log`` in the directory that the ``production.ini`` file lives. You can get fancier with logging as necessary by familiarizing yourself with the Python ``logging`` module configuration format. For example, here's an alternate configuration that logs exceptions via email to a user named ``from@example.com`` to a user named ``to@example.com`` via the SMTP server on the local host at port 25; each email will have the subject ``myapp Exception``: .. code-block:: ini :linenos: # Begin logging configuration [loggers] keys = root, myapp, exc_logger [handlers] keys = console, exc_handler [formatters] keys = generic, exc_formatter [logger_root] level = WARN handlers = console [logger_myapp] level = WARN handlers = qualname = myapp [logger_exc_logger] level = ERROR handlers = exc_handler qualname = exc_logger [handler_console] class = StreamHandler args = (sys.stderr,) level = NOTSET formatter = generic [handler_exc_handler] class = handlers.SMTPHandler args = (('localhost', 25), 'from@example.com', ['to@example.com'], 'myapp Exception') level = ERROR formatter = exc_formatter [formatter_generic] format = %(asctime)s %(levelname)-5.5s [%(name)s][%(threadName)s] %(message)s [formatter_exc_formatter] format = %(asctime)s %(message)s # End logging configuration When the above configuration is used, exceptions will be sent via email instead of sent to a file. For information about logging in general see the `Pythong logging module documentation `_. Practical tips are contained within the `Python logging cookbook `_. More information about the the ``.ini`` logging file configuration format is at https://docs.python.org/library/logging.config.html#configuration-file-format . Settings ========= :mod:`pyramid_exclog`` also has some its own settings in the form of configuration values which are meant to be placed in the ``[app:myapp]`` section of your Pyramid's ``.ini`` file. These are: ``exclog.ignore`` By default, the exception logging machinery will log all exceptions (even those eventually caught by a Pyramid :term:`exception view`) except "http exceptions" (any exception that derives from the base class ``pyramid.httpexceptions.WSGIHTTPException`` such as ``HTTPFound``). You can instruct ``pyramid_exclog`` to override this default in order to ignore custom exception types (or to re-enable logging "http exceptions") by using the ``excview.ignore`` configuration setting. ``excview.ignore`` is a list of dotted Python names representing exception types (e.g. ``myapp.MyException``) or builtin exception names (e.g. ``NotImplementedError`` or ``KeyError``) that represent exceptions which should never be logged. This list can be in the form of a whitespace-separated string, e.g. ``KeyError ValueError myapp.MyException`` or it may consume multiple lines in the ``.ini`` file. This setting defaults to a list containing only ``pyramid.httpexceptions.WSGIHTTPException``. An example: .. code-block:: ini [app:myapp] exclog.ignore = pyramid.httpexceptions.WSGIHTTPException KeyError myapp.exceptions.MyException ``exclog.extra_info`` By default the only content in error messages is the URL that was accessed (retrieved from the url attribute of ``pyramid.request.Request``) and the exception information that is appended by Python's ``Logger.exception`` function. If ``exclog.extra_info`` is true the error message will also include the environ and params attributes of ``pyramid.request.Request`` formatted using ``pprint.pformat()``. The output from ``pyramid.security.unauthenticated_id()`` is also included. This setting defaults to false An example: .. code-block:: ini [app:myapp] exclog.extra_info = true ``exclog.get_message`` If a customized error message is needed, the ``exclog.get_message`` setting can be pointed at a function that takes a request as its only argument and returns a string. It can be either a dotted name or the actual function. For example: .. code-block:: ini [app:myapp] exclog.get_message = myapp.somemodule.get_exc_log_message If ``exclog.get_message`` is set, ``exclog.extra_info`` will be ignored. ``exclog.hidden_cookies`` A list of keys of cookies to hide in the error message. The cookie's value will be replaced with "hidden", so you can still tell whether the cookie was present. This works with either ``exclog.extra_info`` or ``exclog.get_message``. If ``exclog.hidden_cookies`` is set, then any function specified in ``exclog.get_message`` will receive a copy of the request with the cookies already replaced. An example: .. code-block:: ini [app:myapp] exclog.hidden_cookies = auth_tkt another_cookie Explicit "Tween" Configuration ============================== Note that the exception logger is implemented as a Pyramid :term:`tween`, and it can be used in the explicit tween chain if its implicit position in the tween chain is incorrect (see the output of ``ptweens``):: [app:myapp] pyramid.tweens = someothertween pyramid_exclog.exclog_tween_factory pyramid.tweens.excview_tween_factory It usually belongs directly above the ``pyramid.tweens.excview_tween_factory`` entry in the ``ptweens`` output, and will attempt to sort there by default as the result of having ``config.include('pyramid_exclog')`` invoked. Deployment under mod_wsgi ========================= To make logging facilities available when loading an application via mod_wsgi, like it behaves with pserve, you must call the ``logging.fileConfig`` function on the ini file containing the logger entry. Here's an example of a ``run.wsgi`` file: .. code-block:: python import os from pyramid.paster import get_app, setup_logging here = os.path.dirname(os.path.abspath(__file__)) conf = os.path.join(here, 'production.ini') setup_logging(conf) application = get_app(conf, 'main') More Information ================ .. toctree:: :maxdepth: 1 api.rst glossary.rst Reporting Bugs / Development Versions ===================================== Visit https://github.com/Pylons/pyramid_exclog to download development or tagged versions. Visit https://github.com/Pylons/pyramid_exclog/issues to report bugs. Indices and tables ------------------ * :ref:`glossary` * :ref:`genindex` * :ref:`modindex` * :ref:`search`