Using WhiteNoise with Django

Note

To use WhiteNoise with a non-Django application see the generic WSGI documentation.

This guide walks you through setting up a Django project with WhiteNoise. In most cases it shouldn’t take more than a couple of lines of configuration.

I mention Heroku in a few place as that was the initial use case which prompted me to create WhiteNoise, but there’s nothing Heroku-specific about WhiteNoise and the instructions below should apply whatever your hosting platform.

1. Make sure staticfiles is configured correctly

If you’re familiar with Django you’ll know what to do. If you’re just getting started with a new Django project (v1.6 and up) then you’ll need add the following to the bottom of your settings.py file:

STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')

As part of deploying your application you’ll need to run ./manage.py collectstatic to put all your static files into STATIC_ROOT. (If you’re running on Heroku then this is done automatically for you.)

In your templates, make sure you’re using the static template tag to refer to your static files. For example:

{% load static from staticfiles %}
<img src="{% static "images/hi.jpg" %}" alt="Hi!" />

2. Enable WhiteNoise

Edit your wsgi.py file and wrap your WSGI application like so:

from django.core.wsgi import get_wsgi_application
from whitenoise.django import DjangoWhiteNoise

application = get_wsgi_application()
application = DjangoWhiteNoise(application)

That’s it – WhiteNoise will now serve your static files. However, to get the best performance you should proceed to step 3 below and enable gzipping and caching.

3. Add gzip and caching support

WhiteNoise comes with a storage backend which automatically takes care of gzipping your files and creating unique names for each version so they can safely be cached forever. To use it, just add this to your settings.py:

STATICFILES_STORAGE = 'whitenoise.django.GzipManifestStaticFilesStorage'

This uses the new ManifestStaticFilesStorage in Django 1.7, with a backport provided automatically for older versions of Django.

Troubleshooting

If you’re having problems with the WhiteNoise storage backend, the chances are they’re due to the underlying Django storage engine. This is because WhiteNoise only adds a thin wrapper around Django’s storage to add gzip support, and because the gzip code is very simple it generally doesn’t cause problems.

To test whether the problems are due to WhiteNoise or not, try swapping the WhiteNoise storage backend for the Django one. If you’re running Django 1.7 or above, try:

STATICFILES_STORAGE = 'django.contrib.staticfiles.storage.ManifestStaticFilesStorage'

Or if you’re running Django 1.6 or below, try:

STATICFILES_STORAGE = 'django.contrib.staticfiles.storage.CachedStaticFilesStorage'

If the problems persist then your issue is with Django itself (try the docs or the mailing list). If the problem only occurs with WhiteNoise then raise a ticket on the issue tracker.

4. Use a Content-Delivery Network (optional)

The above steps will get you decent performance on moderate traffic sites, however for higher traffic sites, or sites where performance is a concern you should look at using a CDN.

Because WhiteNoise sends appropriate cache headers with your static content, the CDN will be able to cache your files and serve them without needing to contact your application again.

Below are instruction for setting up WhiteNoise with Amazon CloudFront, a popular choice of CDN. The process for other CDNs should look very similar though.

Instructions for Amazon CloudFront

Go to CloudFront section of the AWS Web Console, and click “Create Distribution”. Put your application’s domain (without the http prefix) in the “Origin Domain Name” field and leave the rest of the settings as they are.

It might take a few minutes for your distribution to become active. Once it’s ready, copy the distribution domain name into your settings.py file so it looks something like this:

STATIC_HOST = '//d4663kmspf1sqa.cloudfront.net' if not DEBUG else ''
STATIC_URL = STATIC_HOST + '/static/'

Or, even better, you can avoid hardcoding your CDN into your settings by doing something like this:

STATIC_HOST = os.environ.get('DJANGO_STATIC_HOST', '')
STATIC_URL = STATIC_HOST + '/static/'

This way you can configure your CDN just by setting an environment variable. For apps on Heroku, you’d run this command

heroku config:set DJANGO_STATIC_HOST=//d4663kmspf1sqa.cloudfront.net

Restricting CloudFront to static files

Note

By default your entire site will be accessible via the CloudFront URL. It’s possible that this can cause SEO problems if these URLs start showing up in search results. You can restrict CloudFront to only proxy your static files by following the directions below.

1. Go to your newly created distribution and click “Distribution Settings”, then the “Behaviors” tab, then “Create Behavior”. Put static/* into the path pattern and click “Create” to save.

2. Now select the Default (*) behaviour and click “Edit”. Set “Restrict Viewer Access” to “Yes” and then click “Yes, Edit” to save.

3. Check that the static/* pattern is first on the list, and the default one is second. This will ensure that requests for static files are passed through but all others are blocked.

Available Settings

The DjangoWhiteNoise class takes all the same configuration options as the WhiteNoise base class, but rather than accepting keyword arguments to its constructor it uses Django settings. The setting names are just the keyword arguments uppercased with a ‘WHITENOISE_’ prefix.

WHITENOISE_ROOT
Default:None

Absolute path to a directory of files which will be served at the root of your application (ignored if not set).

Don’t use this for the bulk of your static files because you won’t benefit from cache versioning, but it can be convenient for files like robots.txt or favicon.ico which you want to serve at a specific URL.

WHITENOISE_AUTOREFRESH
Default:settings.DEBUG

Recheck the filesystem to see if any files have changed before responding. This is designed to be used in development where it can be convenient to pick up changes to static files without restarting the server. For both performance and security reasons, this setting should not be used in production.

WHITENOISE_USE_FINDERS
Default:settings.DEBUG

Instead of only picking up files collected into STATIC_ROOT, find and serve files in their original directories using Django’s “finders” API. This is the same behaviour as runserver provides by default, and is only useful if you don’t want to use the default runserver configuration in development.

WHITENOISE_MAX_AGE
Default:60 if not settings.DEBUG else 0

Time (in seconds) for which browsers and proxies should cache non-versioned files.

Versioned files (i.e. files which have been given a unique name like base.a4ef2389.css by including a hash of their contents in the name) are detected automatically and set to be cached forever.

The default is chosen to be short enough not to cause problems with stale versions but long enough that, if you’re running WhiteNoise behind a CDN, the CDN will still take the majority of the strain during times of heavy load.

WHITENOISE_CHARSET
Default:settings.FILE_CHARSET (utf-8)

Charset to add as part of the Content-Type header for all files whose mimetype allows a charset.

WHITENOISE_ALLOW_ALL_ORIGINS
Default:True

Toggles whether to send an Access-Control-Allow-Origin: * header for all static files.

This allows cross-origin requests for static files which means your static files will continue to work as expected even if they are served via a CDN and therefore on a different domain. Without this your static files will mostly work, but you may have problems with fonts loading in Firefox, or accessing images in canvas elements, or other mysterious things.

The W3C explicity state that this behaviour is safe for publicly accessible files.

WHITENOISE_GZIP_EXCLUDE_EXTENSIONS
Default:('jpg', 'jpeg', 'png', 'gif', 'webp','zip', 'gz', 'tgz', 'bz2', 'tbz', 'swf', 'flv', 'woff')

File extensions to skip when gzipping.

Because the gzip process will only create compressed files where this results in an actual size saving, it would be safe to leave this list empty and attempt to gzip all files. However, for files which we’re confident won’t benefit from compression, it speeds up the process if we just skip over them.