Prototype grpc server

[dsyer]

The app now listens on port 10382 for a stream of riff
Messages, processing them using a Function from
the URI passed in on startup.

[markfisher]

getting build failures with this in the log:

java.lang.ClassNotFoundException: io.netty.buffer.PoolArena$1

these are the errors:

Tests in error:
  FunctionConfigurationTests$ConsumerCompositionTests.testConsumer » IllegalState
  FunctionConfigurationTests$FunctionCompositionTests.testFunction » IllegalState
  FunctionConfigurationTests$FunctionCompositionTests.testThen » IllegalState Fa...
  FunctionConfigurationTests$SingleFunctionTests.testDouble » IllegalState Faile...
  FunctionConfigurationTests$SupplierCompositionTests.testFunction » IllegalState
  FunctionConfigurationTests$SupplierCompositionTests.testSupplier » IllegalState

Tests run: 18, Failures: 0, Errors: 6, Skipped: 0

[dsyer]

Bizarre error (cause still unknown - something to do with an abstract test class). I think it's fixed now. Not sure what the abstract class does.

[markfisher]

yes, the build passes now

thanks!

[dturanski]

Maybe extract from here down, along with the mapper, to a separate class

[dturanski]

ProtocolStringList can be a List here

[ericbottard]

Comment leftover from gRPC getting started guide I believe. will remove

[ericbottard]

Can't make this to work with the Greeter sample from riif, modified to return headers like this (needed to that correlationId is propagated):

public class Greeter implements Function<Message<String>, Message<String>> {

	public Message<String> apply(Message<String> in) {
		return MessageBuilder.withPayload("Hello " + in.getPayload())
				.setHeaders(new MessageHeaderAccessor(in)).build();
	}
}

The Message class is not found.

Tried with --function.runner.isolated=false, or with a boot packaged uberjar. No luck.

[ericbottard]

I have a rebased branch with this, with some additional polish that you may want to grab at https://github.com/ericbottard/java-function-invoker/tree/grpc

[dsyer]

@ericbottard I don't think that message function would work on master either. Did you say you had it working there (confused)?

[ericbottard]

No, didn't say (or looked) that it worked on master either.

This is prompted by the fact that, switching to this gRPC style, we now need to take care of propagating the correlationId at the function level (at least for now), so this PR would be useless if we can't use spring-messaging in the function classloader

[dsyer]

It doesn't work on master then, as I suspected. We can discuss OOB.

[jldec]

from OOB discussion today

i don't have enough context to offer guidance on the <Message> idea
i do think it would be ok to release 0.0.4 with a java invoker that supports req/resp on http and flux streams (without correlation) on grpc if that is easier

[dsyer]

Superseded by #26.