Re: Need for machine-readable “Application Interface”

CF Runtime

It is something we are thinking about for the V3 cloud controller API, but
no formal decisions have been made at this point. So feedback and
suggestions are certainly welcome.

Zak and Joseph
CF Runtime Team

On Tue, Jun 16, 2015 at 2:51 PM, Deepak Vij (A) <deepak.vij(a)>

Hi folks, I would like to start a thread on the need for
machine-readable “*Application Interface*” supported at the platform
level. Essentially, this interface describes details such as available
methods/operations, inputs/outputs data types (schema), application
dependencies etc. Any standard specifications language can be used for
this purpose, as long as it clearly describes the schema of the requests
and responses – one can use Web Application Description Language (WADL),
Swagger, RESTful API Modeling Language (RAML), JSON Schema (something like *JSON
Schema for Heroku Platform APIs*) or any other language that provides
similar functionality. These specifications are to be automatically derived
from the code and are typically part of the application development process
(e.g. generated by the build system).

Such functionality can have lots of usage scenarios:

1. First and foremost, Deployment Governance for API Management (our
main vested interest) – API Versioning & Backward Compatibility,
Dependency Management and many more as part of the comprehensive telecom
API Management capabilities which we are currently in the process of
building out.

2. Auto-creating client libraries for your favorite programming

3. Automatic generation of up-to-date documentation.

4. Writing automatic acceptance and integration tests etc.

From historical perspective, in the early 2000s when SOA started out, the
mindset was to author the application contract-first (application interface
using WSDL at that time) and subsequently generate and author code from the
application interface. With the advent of RESTful services, REST community
initially took a stand against such metadata for applications. Although, a
number of metadata standards have none-the-less emerged over the last
couple of years, mainly fueled by the use case scenarios described earlier.

Based on my knowledge, none of this currently exists within Cloud Foundry
at the platform level. It would be highly desirable to have a standard
common “*application interface*” definition at the platform level,
agnostic of the underlying application development frameworks.

I hope this all makes sense. I think this is something could be very
relevant to the “Utilities” PMC. I will also copy&paste this text under
“Utilities” PMC-notes on the github.

I would love to hear from the community on this. Thanks.


Deepak Vij

cf-dev mailing list

Join { to automatically receive all group messages.