1f67eb7403
I moved the checking of If-Match and If-None-Match out of the object server's GET method and into swob so that everyone can use it. The interface is similar to the Range handling; make a response with conditional_response=True, and you get handing of If-Match and If-None-Match. Since the only users of conditional_response are object GET, object HEAD, SLO, and DLO, this has the effect of adding support for If-Match and If-None-Match to just the latter three places and nowhere else. This makes object GET and HEAD consistent for any kind of object, large or small. This also fixes a bug where various conditional headers (If-*) were passed through to the object server on segment requests, which could cause segment requests to fail with a 304 or 412 response. Now only certain headers are copied to the segment requests, and that doesn't include the conditional ones, so they can't goof up the segment retrieval. Note that I moved SegmentedIterable to swift.common.request_helpers because it sprouted a transitive dependency on swob, and leaving it in utils caused a circular import. Bonus fix: unified the handling of DiskFileQuarantined and DiskFileNotFound in object server GET and HEAD. Now in either case, a 412 will be returned if the client said "If-Match: *". If not, the response is a 404, just like before. Closes-Bug: 1279076 Closes-Bug: 1280022 Closes-Bug: 1280028 Change-Id: Id2ee78346244d516b980202e990aa38ce6812de5
Swift
A distributed object storage system designed to scale from a single machine to thousands of servers. Swift is optimized for multi-tenancy and high concurrency. Swift is ideal for backups, web and mobile content, and any other unstructured data that can grow without bound.
Swift provides a simple, REST-based API fully documented at http://docs.openstack.org/.
Swift was originally developed as the basis for Rackspace's Cloud Files and was open-sourced in 2010 as part of the OpenStack project. It has since grown to include contributions from many companies and has spawned a thriving ecosystem of 3rd party tools. Swift's contributors are listed in the AUTHORS file.
Docs
To build documentation install sphinx (pip install sphinx), run
python setup.py build_sphinx, and then browse to /doc/build/html/index.html.
These docs are auto-generated after every commit and available online at
http://docs.openstack.org/developer/swift/.
For Developers
The best place to get started is the "SAIO - Swift All In One". This document will walk you through setting up a development cluster of Swift in a VM. The SAIO environment is ideal for running small-scale tests against swift and trying out new features and bug fixes.
You can run unit tests with .unittests and functional tests with
.functests.
Code Organization
- bin/: Executable scripts that are the processes run by the deployer
- doc/: Documentation
- etc/: Sample config files
- swift/: Core code
- account/: account server
- common/: code shared by different modules
- middleware/: "standard", officially-supported middleware
- ring/: code implementing Swift's ring
- container/: container server
- obj/: object server
- proxy/: proxy server
- test/: Unit and functional tests
Data Flow
Swift is a WSGI application and uses eventlet's WSGI server. After the
processes are running, the entry point for new requests is the Application
class in swift/proxy/server.py. From there, a controller is chosen, and the
request is processed. The proxy may choose to forward the request to a back-
end server. For example, the entry point for requests to the object server is
the ObjectController class in swift/obj/server.py.
For Deployers
Deployer docs are also available at http://docs.openstack.org/developer/swift/. A good starting point is at http://docs.openstack.org/developer/swift/deployment_guide.html
You can run functional tests against a swift cluster with .functests. These
functional tests require /etc/swift/test.conf to run. A sample config file
can be found in this source tree in test/sample.conf.
For Client Apps
For client applications, official Python language bindings are provided at http://github.com/openstack/python-swiftclient.
Complete API documentation at http://docs.openstack.org/api/openstack-object-storage/1.0/content/
For more information come hang out in #openstack-swift on freenode.
Thanks,
The Swift Development Team