django-devserver 0.8.0

Drop-in replacement for Django's runserver

About

A drop in replacement for Django’s built-in runserver command. Features include:

• An extendable interface for handling things such as real-time logging.

• Integration with the werkzeug interactive debugger.

• Threaded (default) and multi-process development servers.

• Ability to specify a WSGI application as your target environment.

Note

django-devserver works on Django 1.3 and newer

Installation

To install the latest stable version:

pip install git+git://github.com/dcramer/django-devserver#egg=django-devserver

django-devserver has some optional dependancies, which we highly recommend installing.

• pip install sqlparse – pretty SQL formatting

• pip install werkzeug – interactive debugger

• pip install guppy – tracks memory usage (required for MemoryUseModule)

• pip install line_profiler – does line-by-line profiling (required for LineProfilerModule)

You will need to include devserver in your INSTALLED_APPS:

INSTALLED_APPS = (
    ...
    'devserver',
)

Usage

Once installed, using the new runserver replacement is easy. You must specify verbosity of 0 to disable real-time log output:

python manage.py runserver

Note: This will force settings.DEBUG to True.

By default, devserver would bind itself to 127.0.0.1:8000. To change this default, DEVSERVER_DEFAULT_ADDR and DEVSERVER_DEFAULT_PORT settings are available.

Additional CLI Options

--werkzeug

Tells Django to use the Werkzeug interactive debugger, instead of it’s own.

--forked

Use a forking (multi-process) web server instead of threaded.

--dozer

Enable the dozer memory debugging middleware (at /_dozer)

--wsgi-app

Load the specified WSGI app as the server endpoint.

Please see python manage.py runserver --help for more information additional options.

Note: You may also use devserver’s middleware outside of the management command:

MIDDLEWARE_CLASSES = (
    'devserver.middleware.DevServerMiddleware',
)

Configuration

The following options may be configured via your settings.py:

DEVSERVER_ARGS = []

Additional command line arguments to pass to the runserver command (as defaults).

DEVSERVER_DEFAULT_ADDR = ‘127.0.0.1’

The default address to bind to.

DEVSERVER_DEFAULT_PORT = ‘8000’

The default port to bind to.

DEVSERVER_WSGI_MIDDLEWARE

A list of additional WSGI middleware to apply to the runserver command.

DEVSERVER_MODULES = []

A list of devserver modules to load.

DEVSERVER_IGNORED_PREFIXES = [‘/media’, ‘/uploads’]

A list of prefixes to surpress and skip process on. By default, ADMIN_MEDIA_PREFIX, MEDIA_URL and STATIC_URL (for Django >= 1.3) will be ignored (assuming MEDIA_URL and STATIC_URL is relative)

Modules

django-devserver includes several modules by default, but is also extendable by 3rd party modules. This is done via the DEVSERVER_MODULES setting:

DEVSERVER_MODULES = (
    'devserver.modules.sql.SQLRealTimeModule',
    'devserver.modules.sql.SQLSummaryModule',
    'devserver.modules.profile.ProfileSummaryModule',

    # Modules not enabled by default
    'devserver.modules.ajax.AjaxDumpModule',
    'devserver.modules.profile.MemoryUseModule',
    'devserver.modules.cache.CacheSummaryModule',
    'devserver.modules.profile.LineProfilerModule',
)

devserver.modules.sql.SQLRealTimeModule

Outputs queries as they happen to the terminal, including time taken.

Disable SQL query truncation (used in SQLRealTimeModule) with the DEVSERVER_TRUNCATE_SQL setting:

DEVSERVER_TRUNCATE_SQL = False

Filter SQL queries with the DEVSERVER_FILTER_SQL setting:

DEVSERVER_FILTER_SQL = (
        re.compile('djkombu_\w+'),  # Filter all queries related to Celery
)

devserver.modules.sql.SQLSummaryModule

Outputs a summary of your SQL usage.

devserver.modules.profile.ProfileSummaryModule

Outputs a summary of the request performance.

devserver.modules.profile.MemoryUseModule

Outputs a notice when memory use is increased (at the end of a request cycle).

devserver.modules.profile.LineProfilerModule

Profiles view methods on a line by line basis. There are 2 ways to profile your view functions, by setting setting.DEVSERVER_AUTO_PROFILE = True or by decorating the view functions you want profiled with devserver.modules.profile.devserver_profile. The decoration takes an optional argument follow which is a sequence of functions that are called by your view function that you would also like profiled.

An example of a decorated function:

@devserver_profile(follow=[foo, bar])
def home(request):
    result['foo'] = foo()
    result['bar'] = bar()

When using the decorator, we recommend that rather than import the decoration directly from devserver that you have code somewhere in your project like:

try:
    if 'devserver' not in settings.INSTALLED_APPS:
        raise ImportError
    from devserver.modules.profile import devserver_profile
except ImportError:
    from functools import wraps
    class devserver_profile(object):
        def __init__(self, *args, **kwargs):
            pass
        def __call__(self, func):
            def nothing(*args, **kwargs):
                return func(*args, **kwargs)
            return wraps(func)(nothing)

By importing the decoration using this method, devserver_profile will be a pass through decoration if you aren’t using devserver (eg in production)

devserver.modules.cache.CacheSummaryModule

Outputs a summary of your cache calls at the end of the request.

devserver.modules.ajax.AjaxDumpModule

Outputs the content of any AJAX responses

Change the maximum response length to dump with the DEVSERVER_AJAX_CONTENT_LENGTH setting:

DEVSERVER_AJAX_CONTENT_LENGTH = 300

devserver.modules.request.SessionInfoModule

Outputs information about the current session and user.

Building Modules

Building modules in devserver is quite simple. In fact, it resembles the middleware API almost identically.

Let’s take a sample module, which simple tells us when a request has started, and when it has finished:

from devserver.modules import DevServerModule

class UselessModule(DevServerModule):
    logger_name = 'useless'

    def process_request(self, request):
        self.logger.info('Request started')

    def process_response(self, request, response):
        self.logger.info('Request ended')

There are additional arguments which may be sent to logger methods, such as duration:

# duration is in milliseconds
self.logger.info('message', duration=13.134)