Add rest endpoint annotations for health.proto

[iagoquirino]

Please answer these questions before submitting your issue.

What version of gRPC are you using?

Using gRPC 1.9.0

What did you expect to see?

If it were possible to implement the health.proto service as REST interface too, it would minimize the duplication and generation of protofiles when using together with the repository of gRPC-gateway( https://github.com/grpc-ecosystem/grpc-gateway).

[carl-mastrangelo]

@iaguera Do you mean adding the http annotations to the proto?

[iagoquirino]

Yes :)

[iagoquirino]

@carl-mastrangelo is there any problem to submit a pull request with that change?

(If not) is there any tip or something procedures to submit the code?

[carl-mastrangelo]

Main issue is dependencies. In order to compile that proto, we would need to pull in a dependency on googleapis.

[ejona86]

Health.proto is shared with other repositories. We need to keep them all consistent. But other than that, seems fine. But it is probably hard to add those annotations to the main grpc/grpc repo. I'd be best to start there (and that is the canonical source of health.proto).