Apache

If you serve Django behind Apache, then you can delegate the file streaming to Apache and get increased performance:

  • lower resources used by Python/Django workers ;
  • faster download.

See Apache mod_xsendfile documentation [1] for details.

Known limitations

  • Apache needs access to the resource by path on local filesystem.
  • Thus only files that live on local filesystem can be streamed by Apache.

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, "apache")
storage = FileSystemStorage(
    location=storage_dir, base_url="".join([settings.MEDIA_URL, "apache/"])
)


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.csrf.CsrfViewMiddleware",
    "django.contrib.auth.middleware.AuthenticationMiddleware",
    "django.contrib.messages.middleware.MessageMiddleware",
    "django_downloadview.SmartDownloadMiddleware",
]
# END middlewares


Then set django_downloadview.apache.XSendfileMiddleware as DOWNLOADVIEW_BACKEND:


Then register as many DOWNLOADVIEW_RULES as you wish:

        "destination_url": "/nginx-optimized-by-middleware/",
        # Bypass global default backend with additional argument "backend".
        # Notice that in general use case, ``DOWNLOADVIEW_BACKEND`` should be
        # enough. Here, the django_downloadview demo project needs to
        # demonstrate usage of several backends.
        "backend": "django_downloadview.apache.XSendfileMiddleware",
    },
    {
        "source_url": "/media/lighttpd/",
        "destination_dir": "/lighttpd-optimized-by-middleware/",
# Test/development settings.

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.

Per-view setup with x_sendfile decorator

Middlewares should be enough for most use cases, but you may want per-view configuration. For Apache, there is x_sendfile:

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.apache import x_sendfile
)


optimized_by_decorator = x_sendfile(
    StorageDownloadView.as_view(storage=storage, path="hello-world.txt"),
    source_url=storage.base_url,
    destination_dir="/apache-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
import django.test
from django.urls import reverse

from django_downloadview.apache import assert_x_sendfile

from demoproject.apache.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("Hello world!\n"))


class OptimizedByMiddlewareTestCase(django.test.TestCase):
    def test_response(self):
        """'apache:optimized_by_middleware' returns X-Sendfile response."""
        setup_file()
        url = reverse("apache: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="/apache-optimized-by-middleware/hello-world.txt",
        )


class OptimizedByDecoratorTestCase(django.test.TestCase):
    def test_response(self):
        """'apache:optimized_by_decorator' returns X-Sendfile response."""
        setup_file()
        url = reverse("apache: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="/apache-optimized-by-decorator/hello-world.txt",
        )

The tests above assert the Django part is OK. Now let’s configure Apache.

Setup Apache

See Apache mod_xsendfile documentation [1] for details.

Assert everything goes fine with healthchecks

Healthchecks are the best way to check the complete setup.

References

[1](1, 2) https://tn123.org/mod_xsendfile/