Swift WebDAV Proxy

The Swift WebDAV Proxy provides a mechanism to connect to OpenStack Swift, the object storage project, via WebDAV. That includes the ability to connect to Swift in HP Helion OpenStack and HP Public Cloud.

How It Works

Swift WebDAV Proxy provides three things:

• A complete WebDAV library.
• A WebDAV server.
• An OpenStack Swift backend (and a file system backend for testing)

The library is built to make it easy to add a custom backend.

Installation

Short version:

$ sudo apt-get intall nodejs npm memcached libcap2-bin
$ git clone https://github.com/hpcloud/swift-webdav
$ cd swift-webdav
$ cp example.settings.json settings.json
$ edit settings.json
$ node server.js

Detailed version:

1. Clone the swift-webdav repository from GitHub Enterprise: git clone https://github.com/hpcloud/swift-webdav
2. Install Node.js. On Ubuntu Linux, you can install with: sudo apt-get install nodejs npm
3. Install Memcached. On Ubuntu Linux you can install that with: sudo apt-get install memcached (Make sure memcached starts.)
4. At a commandline, change directories into the swift-webdav directory: cd swift-webdav
5. Install Node.js dependencies: npm install
6. Create a settings file. The easiest way to do this is: cp example.settings.json settings.json && edit settings.json
7. Start the WebDAV server: node server.js.

You will now have a sing WebDAV server. By default, it is listening on localhost:8000, though you can change that in the settings.

You may now use any supported WebDAV client to connect to the service. (see doc/ for examples.)

Installation on a Server

To install on a server (running on port 443), the following additional steps should be done:

• Install libcap2-bin: sudo apt-get install libcap2-bin
• Allow Node.js to bind to low ports: sudo setcap cap_net_bind_service=+ep /usr/bin/node
• Run as a non-privileged user: node server.js path/to/settings.json

We recommend that you DO NOT install npm on a production system. Instead package up the server and it's JavaScript dependencies then deploy that package.

Running with Forever.js

forever start path/to/server.js path/to/settings.json

Running with the start/stop daemon

$ bin/swift-webdav start

Pronto.js and Swift-WebDAV

Pronto is an application framework for Node.js. Swift-WebDAV is built for that framework. It assumes the basic model, and is designed to make it trivially easy to modify WebDAV behavior using the Pronto configuration.

Start with the server.js file.

Extending

Swift-WebDAV is built to be extended.

To add your own backend:

• Create your own ResourceBridge
• Create a server (or copy and modify server.js)

The code in lib/fs will get you started.

External Utilities

There are a few command line utilities that can be used for testing Swift-WebDAV:

• cadaver: http://www.webdav.org/cadaver/
• nd: http://gohome.org/nd/

FAQ

Why don't you use Content-Length?

We prefer chunked transfer where possible, letting the server optimize the network layer. Node.js handles this for us, provided we don't set the Content-Length header.

Why do some Litmus tests fail?

All major Litmus tests pass. However, there are a few regression tests that do not pass. These are explained below.

Currently, the following Litmus tests fail:

Properties Tests

• props: 15 propnullns, 16 propget: These two tests were a regression test on a bug in Apache mod_dav. Because we respond with the correct error code (400) to both of these requests, the regression (which assumes the bug) breaks. THIS IS THE CORRECT BEHAVIOR.
• prop: 17 prophighunicode, 18 propget: This tests Plane 1 unicode, which JavaScript does not support (http://en.wikipedia.org/wiki/Mapping_of_Unicode_character_planes).

Locks Tests

• locks 23-30: We do not implement the OPTIONAL shared locks portion of RFC-4918. So these tests are skipped by Litmus.
• locks 33: Some versions of Litmus fail test 33 because of a bug in Litmus. It fails to send an If header for a locked resource.