Remote storages¶

In some cases it’s useful to use a CDN for serving static files such as those generated by Django Compressor. Due to the way Django Compressor processes files, it requires the files to be processed (in the {% compress %} block) to be available in a local file system cache.

Django Compressor provides hooks to automatically have compressed files pushed to a remote storage backend. Simply set the storage backend that saves the result to a remote service (see COMPRESS_STORAGE).

django-storages¶

So assuming your CDN is Amazon S3, you can use the boto storage backend from the 3rd party app django-storages. Some required settings are:

AWS_ACCESS_KEY_ID = 'XXXXXXXXXXXXXXXXXXXXX'
AWS_SECRET_ACCESS_KEY = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
AWS_STORAGE_BUCKET_NAME = 'compressor-test'

Next, you need to specify the new CDN base URL and update the URLs to the files in your templates which you want to compress:

COMPRESS_URL = "http://compressor-test.s3.amazonaws.com/"

Note

For staticfiles just set STATIC_URL = COMPRESS_URL

The storage backend to save the compressed files needs to be changed, too:

COMPRESS_STORAGE = 'storages.backends.s3boto.S3BotoStorage'

Using staticfiles¶

If you are using Django 1.3’s staticfiles contrib app or the standalone app django-staticfiles, you’ll need to use a temporary filesystem cache for Django Compressor to know which files to compress. Since staticfiles provides a management command to collect static files from various locations which uses a storage backend, this is where both apps can be integrated.

Make sure the COMPRESS_ROOT and STATIC_ROOT settings are equal since both apps need to look at the same directories when to do their job.

You need to create a subclass of the remote storage backend you want to use; below is an example of the boto S3 storage backend from django-storages:

from django.core.files.storage import get_storage_class
from storages.backends.s3boto import S3BotoStorage

class CachedS3BotoStorage(S3BotoStorage):
    """
    S3 storage backend that saves the files locally, too.
    """
    def __init__(self, *args, **kwargs):
        super(CachedS3BotoStorage, self).__init__(*args, **kwargs)
        self.local_storage = get_storage_class(
            "compressor.storage.CompressorFileStorage")()

    def save(self, name, content):
        name = super(CachedS3BotoStorage, self).save(name, content)
        self.local_storage._save(name, content)
        return name

Set your COMPRESS_STORAGE and STATICFILES_STORAGE settings to the dotted path of your custom cached storage backend, e.g. 'mysite.storage.CachedS3BotoStorage'.
To have Django correctly render the URLs to your static files, set the STATIC_URL setting to the same value as COMPRESS_URL (e.g. "http://compressor-test.s3.amazonaws.com/").