Lighttpd¶
If you serve Django behind Lighttpd, then you can delegate the file streaming to Lighttpd and get increased performance:
- lower resources used by Python/Django workers ;
- faster download.
See Lighttpd X-Sendfile documentation [1] for details.
Note
Currently, django_downloadview supports X-Sendfile
, but not
X-Sendfile2
. If you need X-Sendfile2
or know how to handle it,
check X-Sendfile2 feature request on django_downloadview’s bugtracker [2].
Known limitations¶
- Lighttpd needs access to the resource by path on local filesystem.
- Thus only files that live on local filesystem can be streamed by Lighttpd.
Given a view¶
Let’s consider the following view:
import os
from django.conf import settings
from django.core.files.storage import FileSystemStorage
from django_downloadview import StorageDownloadView
storage_dir = os.path.join(settings.MEDIA_ROOT, 'lighttpd')
storage = FileSystemStorage(
location=storage_dir,
base_url=''.join([settings.MEDIA_URL, 'lighttpd/']))
optimized_by_middleware = StorageDownloadView.as_view(storage=storage,
path='hello-world.txt')
What is important here is that the files will have an url
property
implemented by storage. Let’s setup an optimization rule based on that URL.
Note
It is generally easier to setup rules based on URL rather than based on name in filesystem. This is because path is generally relative to storage, whereas URL usually contains some storage identifier, i.e. it is easier to target a specific location by URL rather than by filesystem name.
Setup XSendfile middlewares¶
Make sure django_downloadview.SmartDownloadMiddleware
is in
MIDDLEWARE_CLASSES
of your Django settings.
Example:
'django.middleware.common.CommonMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django_downloadview.SmartDownloadMiddleware'
]
# END middlewares
Then set django_downloadview.lighttpd.XSendfileMiddleware
as
DOWNLOADVIEW_BACKEND
:
"""Could also be:
Then register as many DOWNLOADVIEW_RULES
as you wish:
DOWNLOADVIEW_BACKEND = 'django_downloadview.lighttpd.XSendfileMiddleware'
'destination_dir': '/apache-optimized-by-middleware/',
# Bypass global default backend with additional argument "backend".
# Notice that in general use case, ``DOWNLOADVIEW_BACKEND`` should be
'source_url': '/media/lighttpd/',
'destination_dir': '/lighttpd-optimized-by-middleware/',
Each item in DOWNLOADVIEW_RULES
is a dictionary of keyword arguments passed
to the middleware factory. In the example above, we capture responses by
source_url
and convert them to internal redirects to destination_dir
.
-
class
django_downloadview.lighttpd.middlewares.
XSendfileMiddleware
(source_dir=None, source_url=None, destination_dir=None)¶ Bases:
django_downloadview.middlewares.ProxiedDownloadMiddleware
Configurable middleware, for use in decorators or in global middlewares.
Standard Django middlewares are configured globally via settings. Instances of this class are to be configured individually. It makes it possible to use this class as the factory in
django_downloadview.decorators.DownloadDecorator
.-
process_download_response
(request, response)¶ Replace DownloadResponse instances by XSendfileResponse ones.
-
get_redirect_url
(response)¶ Return redirect URL for file wrapped into response.
-
is_download_response
(response)¶ Return True for DownloadResponse, except for “virtual” files.
This implementation cannot handle files that live in memory or which are to be dynamically iterated over. So, we capture only responses whose file attribute have either an URL or a file name.
-
process_response
(request, response)¶ Call process_download_response() if
response
is download.
-
Per-view setup with x_sendfile decorator¶
Middlewares should be enough for most use cases, but you may want per-view
configuration. For Lighttpd, there is x_sendfile
:
-
django_downloadview.lighttpd.decorators.
x_sendfile
(view_func, *args, **kwargs)¶ Apply
XSendfileMiddleware
toview_func
.Proxies (
*args
,**kwargs
) to middleware constructor.
As an example:
import os
from django.conf import settings
from django.core.files.storage import FileSystemStorage
from django_downloadview import StorageDownloadView
from django_downloadview.lighttpd import x_sendfile
optimized_by_decorator = x_sendfile(
StorageDownloadView.as_view(storage=storage, path='hello-world.txt'),
source_url=storage.base_url,
destination_dir='/lighttpd-optimized-by-decorator/')
Test responses with assert_x_sendfile¶
Use assert_x_sendfile()
function as a shortcut in your tests.
import os
from django.core.files.base import ContentFile
from django.core.urlresolvers import reverse
import django.test
from django_downloadview.lighttpd import assert_x_sendfile
from demoproject.lighttpd.views import storage, storage_dir
def setup_file():
if not os.path.exists(storage_dir):
os.makedirs(storage_dir)
storage.save('hello-world.txt', ContentFile(u'Hello world!\n'))
class OptimizedByMiddlewareTestCase(django.test.TestCase):
def test_response(self):
"""'lighttpd:optimized_by_middleware' returns X-Sendfile response."""
setup_file()
url = reverse('lighttpd:optimized_by_middleware')
response = self.client.get(url)
assert_x_sendfile(
self,
response,
content_type="text/plain; charset=utf-8",
basename="hello-world.txt",
file_path="/lighttpd-optimized-by-middleware/hello-world.txt")
class OptimizedByDecoratorTestCase(django.test.TestCase):
def test_response(self):
"""'lighttpd:optimized_by_decorator' returns X-Sendfile response."""
setup_file()
url = reverse('lighttpd:optimized_by_decorator')
response = self.client.get(url)
assert_x_sendfile(
self,
response,
content_type="text/plain; charset=utf-8",
basename="hello-world.txt",
file_path="/lighttpd-optimized-by-decorator/hello-world.txt")
-
django_downloadview.lighttpd.tests.
assert_x_sendfile
(test_case, response, **assertions)¶ Make
test_case
assert thatresponse
is a XSendfileResponse.Optional
assertions
dictionary can be used to check additional items:basename
: the basename of the file in the response.content_type
: the value of “Content-Type” header.file_path
: the value of “X-Sendfile” header.
The tests above assert the Django part is OK. Now let’s configure Lighttpd.
Setup Lighttpd¶
See Lighttpd X-Sendfile documentation [1] for details.
Assert everything goes fine with healthchecks¶
Healthchecks are the best way to check the complete setup.
References
[1] | (1, 2) http://redmine.lighttpd.net/projects/lighttpd/wiki/X-LIGHTTPD-send-file |
[2] | https://github.com/benoitbryon/django-downloadview/issues/67 |