A team in Engineering (partially funded by Venus-C) have released a tool, ovf4one, which provides an OCCI interface that accepts OVF and provisions resources through the OpenNebula OCA interface. It is implemented in Java and implements the OCCI specifications and uses OVF messages and OpenNebula as backend.

From a technical perspective, ovf4one is an OCCI to OCA gateway, translating RESTful OCCI calls into OCA RESTful calls and the OVF XML message is translated into OpenNebula VM templates. This project has been realised as part of Venus-C EU project.

We blogged previously about the availability of an OCCI implementation for OpenStack. Below is a screen cast that demonstrates some, not all, of the functionality available.

Demonstration of OCCI on OpenStack from dizz on Vimeo.

Hot on the heels of the OCCI OpenStack implementation (wiki, code review) a number of our community members (big thanks to Eugene from R2AD) will be organising an OpenStack Design Summit unconference OCCI session. All are welcome to it from the inquisitive to the sceptical!

Topics to be discussed include:

• What is OCCI and its goals?
• Where does OCCI fit the OpenStack picture?
• How should OpenStack address “extra” APIs?
• Q&As

The session will be on Wednesday at 4.30pm.in the Golden Gate room.

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.

Today, we are happy and proud to find the German Federal Minstry of Economics and Technology (BMWi) fully endorses OCCI in its freshly published analysis on “The Standardisation Environment for Cloud Computing”.

This is a big vote of confidence in our work which was echoed by the UK G-Cloud report. Being picked up by the German government is obviously kudos to the community’s work, especially as it shows OCCI as a leader of current Cloud standardisation activities.

Lately, OCCI has received a lot of attention: the leading open-source cloud computing software stack implements it, a commercially focused project and related companies builds its whole ecosystem around it, the largest eInfrastructure provider in Europe endorses it, and many other things are ongoing around it.

The study identifies 19 standardisation organisations as “leading”, among which well-known international ones such as ISO, NIST, SNIA, and DMTF are listed next to OGF, the home of OCCI, and other European ones, such as ETSI and BITKOM.

Regarding standards, the report features “20 prototypical cloud standards [that] serve as models, […] and are greatly respected by experts”. Looking at this in detail, it is hugely encouraging to see that OCCI is considered to be the one with the greatest importance (together with OpenStack, which is on the way of speaking OCCI as well, and OAuth, which is orthogonal): the matrix above shows the classification by Booz and Partners on behalf of the BMWi. If you take a look on the upper right, you’ll find that OCCI is not only the one with the greatest maturity and quality, but also has the highest dissemination potential!

The report makes an analysis from the European and German point of view, and discusses the current field of standardisation in the Cloud arena. Stating that “the standardisation environment for cloud computing is only just starting to develop”, the report identifies OCCI (next to OVF, OpenStack, and CDMI) as “proving attractive”. It features a taxonomy of standards in cloud computing along challenges they address (“why?”) and the basis of their approach (“how?”), and identifies nine challenges, with data privacy the most prevalent, next to three fields (technology, management, and legal).

Well done to all and thanks to Alexander for the article and translations!

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.

Interoperability is key belief in OCCI. The OCCI specifications set out in text how to implement the API and formats, however it is still up to our community and adopters to implement this. It is often the case when implementing a specification certain implementation decisions made can have an impact on an implementations interoperability. It is for this reason why this ANTLR grammar has been created (thanks to SLA@SOI) to aid developers in creating their parser. The ANTLR grammar specifies the text rendering format in an abstract language known as a grammar.

What?

The grammar defined, when used with the ANTLR tools, will generate a lexer and parser that will validate any valid OCCI text format. The grammar itself does not currently check whether a value associated with an attribute is valid. Rather it primarily ensures that the structure of the request is valid. It is still up to the implementer that service behaviours (e.g. correctly responding to HTTP GETs) are implemented correctly.

Why?

One of the key strengths of ANTLR, outside of its lexer/parser technology, is it has a wide range of target languages (18), so your favourite language has a good chance!  This is an important advantage as this enables multiple implementations of OCCI (client or server) to all share a the same rules that parse the OCCI text format, regardless of language.

The Goodies

There are two grammars currently defined, one based on the other:

1. occi-antlr-grammar: this solely defines the grammar and does not contain any target language specifics. It can be used as the foundation of target language specific OCCI grammars. An example of this extension is the occi-antlr-java. This grammar can generate lexer and parsers, however they will only validate the input and not extract values from the supplied input. If extracted values are required, a very common case, then the occi-antlr-java grammar gives an example of this.
2. occi-antlr-java: this extends occi-antlr-grammar to include target language specifics. The target language used is Java. In this grammar file there are Java-specific ANTLR actions that extract the values from a valid OCCI text request/responses.
3. occi-antlr-ruby: this just like occi-antlr-java extends the occi-antlr-grammar to include ruby language specifics. This was contributed by GWDG.

There are a number of rules that are present within the OCCI grammar that can be reused in order to validate certain supplied values. This would describe a second pass parsing phase. In the case that an implementer would like to validate a URI value then they can do so by using this URI grammar.

The following presentation also goes through some details related to ANTLR and the OCCI grammar.

We hope you find this useful! If there are any problems, issues or suggestions open a ticket.

CompatibleOne provides an implementation of the OCCI server in C. You can also see all the OCCI-based services and interfaces that CompatibleOne supports. CompatibleOne has a clear focus on the need of interoperability in the Cloud and so uses OCCI.

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!

Dear OGF Board and WG participants:

We would like to inform you that the Open Cloud Computing Interface Core & Models and Infrastructure specification documents, GFD.183 and GFD.184, were published today as OGF Proposed Recommendations and are now available for downloading on the http://ogf.org/documents site.

We are very proud of all of the accomplishments of all OGF work groups and of the entire OGF document series. Thank you for all of your work, regardless of the work group or area in which you are making contributions.

OCCI represents the work of a dedicated set of participants that deserves highlighting, however, and that opens up a significant set of opportunities for new work in OGF in the area of cloud computing. Here for your information is some of the text that we have been using in announcing the release of the first two documents in the series. The next document covering the HTTP rendering just completed its public comment period and should be completed and ready for publication shortly.

OCCI is a general-purpose set of specifications for cloud-based interactions with resources in a way that is explicitly vendor-independent, platform-neutral and can be extended to solve a broad variety of problems in cloud computing. The OCCI specification set is a product of the Open Grid Forum. OGF is a leading development organization for open standards in the area of distributed networking, computing and storage with an emphasis on technologies for large-scale distributed computing. OGF develops its standards through an open process that gathers input and contributions from the community and refines them through peer review and public comment to produce standards, guidance and information of value to the community through the Grid Final Document (GFD) series.

We are very proud of OCCI and think that it provides an important and timely set of contributions to cloud computing technology that is already gathering great interest and rapid evidence of adoption by a broad range of participants in the cloud computing community.

Congratulations to the OCCI working group and its participants. More information can be found on the OGF and OCCI working group sites at http://ogf.org and http://occi-wg.orgrespectively. Please let me know if you have any further questions.

Thanks,
Alan Sill
VP of Standards
Open Grid Forum

Source.: http://www.ogf.org/pipermail/wg-all/2011-April/000313.html