from django.conf import settings
from django.http import HttpResponsePermanentRedirect

class PermanentRedirectMiddleware(object):
    def process_request(self, request):
        if hasattr(settings, 'HTTP_HOST_DOMAIN') and\
           'HTTP_HOST' in request.META and \
           request.META['HTTP_HOST'] != settings.HTTP_HOST_DOMAIN:
            return HttpResponsePermanentRedirect("http%s://%s%s"%(
                request.is_secure() and 's' or '',
                settings.HTTP_HOST_DOMAIN,
                request.get_full_path(),
                )
            )