Hi hono-devs,
I am interested to provide CoAP protocol adapter support for Hono as part of GSoC '18. I am a PhD student (in the preparatory phase) at Saarland University (Germany).
I have an interest in contributing to opensource and started doing so for the Apache Jackrabbit project in 2014. The reason for choosing an Eclipse project for my GSoC is that I have been using the Eclipse IDE for all my Java projects and want to use this opportunity to contribute back to the community.
For Apache Jackrabbit, I implemented a missing feature within the client-server-based implementation of JSR 283[1] present with Apache Jackrabbit[2]. While the reference implementation already provided support for access control management, as defined by the specification (JSR 283), this was outstanding in the "JCR Remoting"[3]. My contribution was to fill that gap and the end result was appreciated by the community[4].
I have forked the Hono and Californium repositories and already have my development environment setup. I looked at the Hono Protocol Adapter base class and studied how the Http protocol adapter was implemented as an extension to the base protocol adapter. Concretely, I looked at how the implementation was tested by going through the org.eclipse.hono.adapter.http.AbstractVertxBasedHttpProtocolAdapterTest and org.eclipse.hono.adapter.http.vertx.VertxBasedHttpProtocolAdapterTest unit tests.
I also spent sometime experimenting with a custom HTTP protocol adapter as described in [5]. For californium, I started the HelloWorldServer and use the copper firefox add-on as a client to interract with the server.
I just have few questions:
1. Should the coap adapter be built on top of Californium i.e use it as a library?
2. Who will be the consumer of the API exposed by the coap adapter, IoT devices only?
3. Where on the stack will the CoAP server sit on? Or do we not care?
