blacknoise

blacknoise is an ASGI app for static file serving inspired by whitenoise and following the principles of low maintenance software.

Using blacknoise to serve static files

Install blacknoise into your Python environment:

pip install blacknoise

Wrap your ASGI application with the BlackNoise app:

from blacknoise import BlackNoise
from django.core.asgi import get_asgi_application
from pathlib import Path

BASE_DIR = Path(__file__).parent

application = BlackNoise(get_asgi_application())
application.add(BASE_DIR / "static", "/static")

The example uses Django, but you can wrap any ASGI application.

BlackNoise will automatically handle all paths below the prefixes added, and either return the files or return 404 errors if files do not exist. The files are added on server startup, which also means that BlackNoise only knows about files which existed at that particular point in time.

BlackNoise doesn't watch the added folders for changes; if you add new files you have to restart the server, otherwise those files aren't served. It doesn't cache file contents though, so changes to files are directly picked up.

Improving performance

BlackNoise has worse performance than when using an optimized webserver such as nginx and others. Sometimes it doesn't matter much if the app is behind a caching reverse proxy or behind a content delivery network anyway. To further support this use case BlackNoise can be configured to serve media files with far-future expiry headers and has support for serving compressed assets.

Serving pre-compressed assets

Compressing is possible by running:

python -m blacknoise.compress static/

BlackNoise will try compress non-binary files using gzip or brotli (if the Brotli library is available), and will serve the compressed version if the compression actually results in (significantly) smaller files and if the client also supports it. Files are compressed in parallel for faster completion times.

Setting far-future expiry headers

Far-future expiry headers can be enabled by passing the immutable_file_test callable to the BlackNoise constructor:

def immutable_file_test(path):
    return True  # Enable far-future expiry headers for all files

application = BlackNoise(
    get_asgi_application(),
    immutable_file_test=immutable_file_test,
)

Maybe you want to add some other logic, for example check if the path contains a hash based upon the contents of the static file. Such hashes can be added by Django's ManifestStaticFilesStorage or by appropriately configuring bundlers such as webpack and others.

License