Developing with Rucio

Rucio Clients

Rucio includes a client class to remove some of the complexity of dealing with raw HTTP requests against the RESTful API.

All client methods are accessible through the high-level class Client. Below is one example of using Rucio Client class:

from rucio.client import Client
rucio_client = Client()
rucio_client.ping()

The methods are separated per resource type. The API in full can be viewed here.

Errors and Exceptions

In the case of an error, Rucio returns a Python Exception with the appropriate Traceback, a detailed error string, and a unique error number. If the error occurred on the server side, it will be propagated to the client. The command line clients will exit back to the shell with the POSIX errno of the unique Rucio error number. The full and up to date list can be found in the Exception definition.

RESTful APIs

Each resource can be accessed or modified using specially formed URLs and the standard HTTP methods:

GET to read
POST to create
PUT to update
DELETE to remove

We require that all requests are done over SSL. The API supports JSON formats. Rucio uses OAuth to authenticate all API requests. The method is to get an authentication token, and use it for the rest of the requests. Descriptions of the actions you may perform on each resource can be found in the REST API documentation.

Date format

All dates returned are in UTC and are strings in the following format (RFC 1123, ex RFC 822): Mon, 13 May 2013 10:23:03 UTC

In code format, which can be used in all programming languages that support strftime or strptime:

%a, %d %b %Y %H:%M:%S UTC

SSL only

We require that all requests(except for the ping) are done over SSL.

Response formats

The currently-available response format for all REST endpoints is the string-based format JavaScript Object Notation (JSON). The server answer can be one of the following content-type in the http Header:

Content-type: application/json
Content-Type: application/x-json-stream

In the last case, it corresponds to JSON objects delimited by newlines(streaming JSON for large answer), e.g.:

{ "id": 1, "foo": "bar" }
{ "id": 2, "foo": "baz" }
...

Error handling

Errors are returned using standard HTTP error code syntax. Additional info is included in the header or the body of the return call, JSON-formatted with the parameters:

ExceptionClass
ExceptionMessage

Where ExceptionClass refers to Rucio Exceptions.