rOCCI – A Ruby OCCI Framework

rOCCI is an OCCI 1.1 compliant server implementation written in Ruby. Through its modular architecture it can be easily extended to support arbitrary Cloud Frameworks.

rOCCI as mentioned in our last blog post, is the OCCI implementation that powers the work which enables OCCI interoperability with Amazon EC2.

Work on rOCCI started as part of the EU FP7 project SLA@SOI under the working name OGF-OCCI in early 2011. The goal was to develop an OCCI 1.1 compliant server which initially supports OpenNebula and can later be easily extended to support other Cloud Frameworks. As OpenNebula offered a robust Ruby API binding, it was decided to develop the project in Ruby as well. Soon after work on the implementation started it was accepted as an official OpenNebula Ecosystem project.

Interoperability with other implementations of the OCCI standard was ensured by taking part in testing sessions during the SNIA Cloud Plugfests and using OCCI compliance tools such as the OCCI ANTLR Grammar and the DoYouSpeakOCCI tool. For the last Plugfest taking place at the end of February 2012, the project was renamed to rOCCI in order to distinguish it from the name of the standard (OGF-OCCI).

The current architecture of rOCCI is shown in the following overview:

Detailed architecture showing the components of rOCCI

Current features include:

rOCCI is currently mainly developed by employees of GWDG. New contributors are very welcome. For more information visit:

Home of rOCCI

rOCCI on GitHub

OCCI’fied Amazon EC2

OCCI has been successfully mapped and implemented upon the Amazon EC2 API. The work has been carried out by TU Dortmund University in cooperation with the compute and research center GWDG. The implementation uses the rOCCI framework – more on that in a later post!

Screencast EC2 in rOCCI from Max Günther on Vimeo.


OCCI and OpenStack

OpenStack is one of the major players in the cloud community at the moment. Still it currently lacks an standardized Interface which can be used to manage VMs. This changes now! During the Cloud Plugfest OCCI has been demoed on top of OpenStack.

The blueprint (details on wiki) for this feature enhancement has been around a while now. And based on this blueprint a first implementation has been created.

Andy Edmonds presented the following slides during the Cloud Plugfest in Düsseldorf which highlight more details of the OCCI interface for OpenStack

As noted this work has partly been sponsored by dgsi and FI-WARE. Now on to interoperability testing and looking into getting other Standards like CDMI on top of OpenStack.

OCCI HTTP Rendering Spec Released

The OCCI HTTP Rendering specification defines how to interact with the OCCI Core Model using the RESTful OCCI API. The document defines how the OCCI Core Model can be communicated with and thus serialised using the HTTP protocol via RESTful semantics.

This is the last document in the v1.1 document series and is now available on the main OGF web site as document GFD.185.

Thanks to all that contributed content and reviews!


OCCI Presentation – A Walkthrough of the Specification

The following slide-set gives an overview (incl. examples) of the OCCI specification:

Please see the ‘speaker notes’ for more information on each slide. The presentation of course can be shared upon request in several formats. Feel free to contact the chairs of the OCCI working group.

Happy Birthday OCCI!

It was two years ago when the first official mail on the then new OCCI mailing list was sent. Since than the OCCI community had a steady grow and is still going strong! This is all the more appropriate given the release of OCCI v1.1 Core and Infrastructure specification documents. As a little special for today we have a celebration version of our logo:

We want to thank the designer of our official Logo since he was so kind to create this special birthday version for us.

OCCI 1.1 Document Series in Public Comment

As of today, all the documents for the revised version (1.1) of the OCCI document series are now in public comment. A lot of work by the OCCI community has gone into this revision so a huge “thanks!” goes out to all who have contributed to the many discussions on the mailing list, IRC, wiki and confcalls. This version paves the way to much exciting implementation work and plugfests in the upcoming months. If you would like to make comments and have your views heard and taken on board, now is an excellent time to do so. Simply:
  1. navigate to the public comments section on the OGF website,
  2. grab a copy of any or all the specification documents
  3. read the spec
  4. submit any comments, questions or improvements back to the public comments page (this can be anonymous if you prefer)