Reflection service doesn't include service methods

[sishbi]

Describe the feature

The reflection service 'list services' does not include services registered via 'addCallHandler', it only includes services registered via 'addService'
All of our services use a custom handler for each service method, so none of the services are listed on the server when using reflection.

Contribution

No response

[vietj]

@zZHorizonZz can you have a look ?

[zZHorizonZz]

So the issue here would be that we are not really working with methodCallHandlers at all in reflection, we are only using services. The issue with methods registered through callHandler is that we only have access to ServiceName, but we don't really have access to descriptors, which are necessary for reflection.

[sishbi]

GrpcIoServer works with ServiceDescriptor though... I think

[zZHorizonZz]

GrpcIoServer works with ServiceDescriptor though... I think

That is GrpcIoServer. The ReflectionService is using the GrpcServer interface and is getting the info through service(), so I don't think we can support it in GrpcServerImpl without needing to do a bunch of refactoring. Although GrpcIoServer might be possible, we would probably need to have a separate list and override the service() method.

What do you think @vietj

[sishbi]

I am thinking that if you use this to register a service method:
public <Req, Resp> GrpcIoServerImpl callHandler(MethodDescriptor<Req, Resp> methodDesc, Handler<GrpcServerRequest<Req, Resp>> handler)
Then it also adds to the services list...

[zZHorizonZz]

I am thinking that if you use this to register a service method:
public <Req, Resp> GrpcIoServerImpl callHandler(MethodDescriptor<Req, Resp> methodDesc, Handler<GrpcServerRequest<Req, Resp>> handler)
Then it also adds to the services list...

Yes, that is what I'm thinking, although we cannot really access the service list from outside of the GrpcServerImpl, nor can we modify the result returned by services as that returns an unmodifiable list. But I think there could be a separate list, and an override of the services method would basically combine the results of these two, where the new list would only hold pseudo/internal service implementations, which would get created if they don't already exist when using grpcIo callHandler.