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

This is the major feature branch, as maintained by DigiACTive. It has diverged considerably from the original project.

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.

Installing

To get started with django-storage-swift, install it:

• This version is not on PyPI, so you need to: pip install git+git://github.com/DigiACTive/django-storage-swift.git@digiactive#egg=django-storage-swift

  Be careful with subsequent uses of pip freeze, as it will just print the package name and lose the git stanza - you'll need to manually edit any requirements.txt files.

• In your settings.py file, add:

  DEFAULT_FILE_STORAGE='swift.storage.SwiftStorage'

Configuring

django-storage-swift recognises the following options.

Option	Default	Description
SWIFT_AUTH_URL	None	The URL for the auth server, e.g. http://127.0.0.1:5000/v2.0
SWIFT_USERNAME	None	The username to use to authenticate.
SWIFT_KEY	None	The key (password) to use to authenticate.
SWIFT_AUTH_VERSION	1	The version of the authentication protocol to use.
SWIFT_TENANT_NAME	None	The tenant name to use when authenticating.
SWIFT_CONTAINER_NAME	None	The container in which to store the files.
SWIFT_AUTO_CREATE_CONTAINER	False	Should the container be created if it does not exist?
SWIFT_BASE_URL	None	The base URL from which the files can be retrieved, e.g. http://127.0.0.1:8080/.
SWIFT_USE_TEMP_URLS	False	Generate temporary URLs for file access (allows files to be accessed without a permissive ACL).
SWIFT_TEMP_URL_KEY	None	Temporary URL key --- see the OpenStack documentation.
SWIFT_TEMP_URL_DURATION	30*60	How long a temporary URL remains valid, in seconds.

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.connection

The result should be <<swiftclient.client.Connection object ...>>

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.