django-storage-swift: a storage layer for OpenStack Swift

django-storage-swift allows Django applications to use OpenStack Swift as a file storage layer.

Features

• Reads/writes files into/out of Swift.
• Automatically derives the correct URL to allow files to be accessed through a web browser based on information returned from the authorisation server.
  • Allows you to override the host, port and path as necessary.
  • Supports the generation of temporary URLs to restrict access to files.

Usage

You can install django-storage-swift through pip. To store your media files on swift, add the following line to your settings.py or local_settings.py:

DEFAULT_FILE_STORAGE = 'swift.storage.SwiftStorage'

To store your static files on swift, add the following line:

STATICFILES_STORAGE = 'swift.storage.StaticSwiftStorage'

This will use another container.

Configuring

django-storage-swift recognises the following options.

SWIFT_BASE_URL

django-swift-storage will automatically query the authentication server for the URL where your files can be accessed, which takes the form http://server:port/v1/AUTH_token/.

Sometimes you want to override the server and port (for example if you're developing using devstack inside Vagrant). This can be accomplished with SWIFT_BASE_URL.

The provided value is parsed, and:

• host and port override any automatically derived values
• any path component is put before derived path components.

So if your auth server returns http://10.0.2.2:8080/v1/AUTH_012345abcd/ and you have SWIFT_BASE_URL="http://127.0.0.1:8888/foo", the url function will a path based on http://127.0.0.1:8888/foo/v1/AUTH_012345abcd/.

Temporary URLs

Temporary URLs provide a means to grant a user permission to access a file for a limited time only and without making the entire container public.

Temporary URLs work as described in the Swift documentation. (The code to generate the signatures is heavily based on their implementation.) They require setup of a key for signing: the process is described in the OpenStack documentation.

Use

Once installed and configured, use of django-storage-swift should be automatic and seamless.

You can verify that swift is indeed being used by running, inside python manage.py shell:

from django.core.files.storage import default_storage
default_storage.http_conn

The result should be <>

Openstack Keystone/Identity v3

To authenticate with a swift installation using Keystone AUTH and the Identity v3 API, you must also specify either the domain ID or name that your user and project (tenant) belongs to.

SWIFT_AUTH_URL='https://keystoneserver/v3'
SWIFT_AUTH_VERSION='3'
SWIFT_USERNAME='<>'
SWIFT_KEY='<>'
SWIFT_TENANT_NAME='<>'
SWIFT_USER_DOMAIN_NAME='<>'
SWIFT_PROJECT_DOMAIN_NAME='<>'

Troubleshooting

• I'm getting permission errors accessing my files: If you are not using temporary URLs, you may need to make the container publically readable. See this helpful discussion. If you are using temporary URLs, verify that your key is set correctly.
• I'm getting empty or truncated file uploads: Issues with some content types may cause an incorrect content_length header to be sent with file uploads, resulting in 0 byte or truncated files. To avoid this, set SWIFT_CONTENT_LENGTH_FROM_FD: True.

Quickstart

# This was executed on a VM running a SAIO, for example with
# https://github.com/swiftstack/vagrant-swift-all-in-one

# Create two world-readable containers
swift post -r ".r:*" django
swift post -r ".r:*" django-static

# A virtualenv to keep installation separated
virtualenv sampleenv
source sampleenv/bin/activate
pip install django-storage-swift
pip install django

# Create a sample project
django-admin startproject sampleproj
export DJANGO_SETTINGS_MODULE=sampleproj.settings
cd sampleproj/

# A few required settings, using SAIO defaults
cat <> sampleproj/settings.py
DEFAULT_FILE_STORAGE='swift.storage.SwiftStorage'
STATICFILES_STORAGE ='swift.storage.StaticSwiftStorage'
SWIFT_AUTH_URL='http://127.0.0.1:8080/auth/v1.0'
SWIFT_USERNAME='test:tester'
SWIFT_KEY='testing'
SWIFT_CONTAINER_NAME='django'
SWIFT_STATIC_CONTAINER_NAME='django-static'
EOF

# Create the initial DB data
python manage.py migrate

# This uploads static files to Swift
python manage.py collectstatic --noinput

# Now open http://127.0.0.1:8000/admin/ in your browser
# Static files like CSS are served by Swift
python manage.py runserver