btorch / swift_undelete

Undelete middleware for OpenStack Swift

Swift Undelete

Middleware for OpenStack Swift that implements "undelete" functionality.

When this middleware is installed, an object DELETE request will cause a copy of the object to be saved into a "trash location" prior to deletion. Subsequently, an administrator can recover the deleted object.

Caveats

• This does not provide protection against overwriting an object. Use Swift's object versioning if you require overwrite protection.

• If your account names are near the maximum length, this middleware will fail to create trash accounts, leaving some objects unable to be deleted.

• If your container names are near the maximum length, this middleware will fail to create trash containers, leaving some objects unable to be deleted.

• If your cluster is too full to allow an object to be copied, you will be unable to delete it. In extremely full clusters, this may result in a situation where you need to add capacity before you can delete objects.

• Requires Swift 1.12.0+, which introduced system metadata.

Enabling

Add a new filter section to your proxy-server.conf:

[filter:swift_undelete]
use = egg:swift_undelete#undelete
trash_prefix = .trash-
trash_lifetime = 120
block_trash_deletes = no
enable_by_default = yes

Add the filter to the [pipeline:main] section:

[pipeline:main]
pipeline = catch_errors ... <auth middleware> swift_undelete ... proxy-server

By placing swift_undelete somewhere after auth, you avoid unnecessary additional auth requests.

Future work

• Move to separate account, not container, for trash. This requires Swift to allow cross-account COPY requests.

• If block_trash_deletes is on, modify the Allow header in responses (both OPTIONS responses and any other 405 response).

Swift-Undelete is Copyright (c) 2014 SwiftStack, Inc. and licensed under the Apache 2.0 license (see LICENSE).