django-throttling 0.0.1

Basic throttling app for Django

django-throttling is a an attempt at creating a simple app that allows to apply frequency limits to user’s requests.

Features

• per-view maintenance mode

• per-view timeouts

• view disabling

• timeouts are configured with respect to request.method

• redirects

• custom congestion views

• view timeouts support callbacks

Requirements

• django cache

Installation

Download django-throttling using one of the following methods:

pip

pip install django-throttling

Checkout from GitHub

Use one of the following commands:

git clone http://github.com/night-crawler/django-throttling.git

Configuration

Add ‘django_throttling’ into INSTALLED_APPS in settings.py:

INSTALLED_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    ...
    'django_throttling',
    ...
)

MIDDLEWARE

Add django_throttling.middleware.ThrottleMiddleware to your MIDDLEWARE_CLASSES in settings.py. You may need ‘request.user’ or ‘request.session’, etc., so insert it in a right place according to your needs.

SETTINGS

• DJANGO_THROTTLING_ENABLED: enables ‘django-throttling’. Default is False.

• DJANGO_THROTTLING_CACHE_EXPIRE: how long should we keep last_access time. If you set a large timeout for view, i.e. 24h, make sure that DJANGO_THROTTLING_CACHE_EXPIRE is not less than your timeout. Default is 60*60

• DJANGO_THROTTLING_CACHE_PREFIX: a cache prefix for keys. Default is THROTTLING

• THROTTLING_CACHE_KEY_PATTERNS: a dict with patterns for building the cache keys. May be redefined in app settings. Defaults are:

  • view_method: cache key pattern for a view with a method specified. Default pattern: %(prefix)s:%(view)s:%(uid)s:%(ip)s:%(method)s

  • view: cache key pattern for a view. Default pattern: %(prefix)s:%(view)s:%(uid)s:%(ip)s

  • site_method: cache key pattern for a whole site with a method. Default pattern: %(prefix)s:%(uid)s:%(ip)s:%(method)s

  • site: a global pattern. Default: %(prefix)s:%(uid)s:%(ip)s

• DJANGO_THROTTLING_IGNORE_ADMINS: ignore throttling if user is admin. Default is True.

• DJANGO_THROTTLING: a dict with app-path keys that configures the limits. I.e.: {'django.contrib.admin.options.change_view': {'all': 50, 'post': 5000}}

See Usage. For more.

Usage

Global fall-backs

Fall-back timeouts setup for any request at the current site:

DJANGO_THROTTLING = {
    'all': 1000,
    'post': 10000,
    'congestion': 'forum.views.congestion',
}

That stands for “one request per second, one POST request per 10s”. congestion is a view called after the throttle check, if it failes. It may be a uri, i.e. /forum/congestion/. Must uri start with ‘/’.

The simplest congestion view may look like:

def congestion(request, congestion_bundle):
    user = request.user
    progress = int(float(congestion_bundle['delta']) / congestion_bundle['timeout'] * 100)
    c = Context({'user': user, 'congestion_bundle': congestion_bundle, 'progress': progress})
    return render_to_response(get_theme_template(user, 'congestion.html'), c,
        context_instance=RequestContext(request)
    )

congestion_bundle is a dict, populated from a process_request():

congestion_bundle = {
    'view_func': self.view_func,
    'view_args': self.view_args,
    'view_kwargs': self.view_kwargs,
    'timeout': timeout,
    'delta': delta,
}

You may disable all POST’s on your site (‘maintenance mode’):

DJANGO_THROTTLING = {
    'all': 1000,
    'post': False,
    'congestion': 'forum.views.congestion',
}

In that case you will get HttpResponseBadRequest() on any POST.

Also, you may redirect your’s POST users to an any page:

DJANGO_THROTTLING = {
    'all': 1000,
    'post': '/',
    'congestion': 'forum.views.congestion',
}

or you can use a custom maintenance view for it:

DJANGO_THROTTLING = {
    'all': 1000,
    'post': 'forum.views.maintenance',
    'congestion': 'forum.views.congestion',
}

Maintenance view may look like:

def maintenance(request, maintenance_bundle):
    return HttpPreResponse(maintenance_bundle)

If you need a special cache key builder, or just to set a timeout is not enough for you, you can use a callback for, i.e., POST, that have to make it’s checks and return a tuple of cache key and one of the supported timeout types:

DJANGO_THROTTLING = {
    'all': 1000,
    'post': 'callable:helpers.trash.my_callback',
    'congestion': 'forum.views.congestion',
}

And here’s the example callback:

def my_callback(request, view_func, view_args, view_kwargs):
    return 'some_strange_key_123', 10000

The full set of arguments the original view had is provided.

And don’t forget, that it is a fallback section, that used ONLY if you have no detailed rule for view throttling.

Per-view throttling

Per-view throttling is almost the same:

DJANGO_THROTTLING = {
    'all': 1000,
    'post': 'callable:helpers.trash.my_callback',
    'congestion': 'forum.views.congestion',

    'django.contrib.admin.options.change_view': {
        'post': False,
        'all': 0,
        'uri': '/admin/forum/post/23/',
        # 'post': 'callable:helpers.trash.my_callback',
        # 'all': 4000,
    },
}

First, it will disable all limits for django.contrib.admin.options.change_view. Then, it will disable the POST method for this view, ONLY if the request.path starts with ‘/admin/forum/post/23/’. Other options from global setup are permitted.