File storage for development server

storages.py

from django.core.files.base import ContentFile
from django.core.files.storage import FileSystemStorage
from django.utils.encoding import filepath_to_uri
from django.utils.log import getLogger
from django.conf import settings

from urllib2 import urlopen, HTTPError
from urlparse import urljoin


logger = getLogger(__name__)


class FallbackStorage(FileSystemStorage):
    """
    A storage that will download files from a remote location when the file
    doesn't exist locally. Useful for downloading assets from your production
    server from your development server on demand.
    """
    
    def __init__(self, *args, **kwargs):
        self.fallback_url = getattr(settings, 'FALLBACK_STORAGE_URL', '/')
        super(FallbackStorage, self).__init__(*args, **kwargs)

    def _fetch(self, name):
        url = urljoin(self.fallback_url, filepath_to_uri(name))
        try:
            content = ContentFile(urlopen(url).read())
            self._save(name, content)
        except HTTPError:
            logger.warning('Failed fetching %s' % name)
            return False
        return True

    def url(self, name):
        if not self.exists(name):
            self._fetch(name)
        return super(FallbackStorage, self).url(name)