Hi, I wanted to find out if any of you guys know what the status is of gRPC for kotlin #multiplatform?

it looks like the google grpc kotlin examples are using a different plugin hierarchy from a medium article that has a "kotlin-grpc-plugin" and if i want to get an idea of the samples i should ... run a shellscript?

@jimn what are you trying to do? Compile protos? Call a grpc service?

Looks like grpc Kotlin finally getting some love https://github.com/grpc/grpc-kotlin Coroutine stubs: https://github.com/grpc/grpc-kotlin/tree/master/examples/src/main/kotlin/io/grpc/examples/routeguide/RouteGuideServer.kt

Happening rn

@Gary and for anyone else who missed it https://www.cncf.io/webinars/announcing-open-source-grpc-kotlin/

hello! are there any suggestions for grpc client? e.g. looks like https://github.com/yidongnan/grpc-spring-boot-starter is pretty popular but wondering if there is something better

hello! trying to work around https://github.com/grpc/grpc-kotlin/issues/66 with setting up MDC from GRPC context -> while searching online it looks all examples point to GO

metadata.FromIncomingContext

. Does anyone know if there is similar function for Kotlin/Java?

btw you can also use https://github.com/marcoferrer/kroto-plus to generate nice Kotlin DSL style builders

hi! is there a way in grpc-kotlin to customize the worker coroutine name on client side?

"SendMessage worker for ${method.fullMethodName}"

seems overkill

Hello 👋 Anyone knows whether it is possible to limit which

.proto

files are going to be extracted by the protobuf plugin? i.e. configure

extractIncludeProto

task to exclude certain files?

Has anyone developed a nice way of wrapping the generated java builders to make things a bit nicer in kotlin? At the moment we are doing

val message = with(MyMessage.newBuilder()) {
    someField = 1
    build()
}

I was thinking it would be nicer to do something like....

val message = build(MyMessage) {
   someField = 1
}

... but my Kotlin isn't good enough to be able to write that build function yet 😄

Hello 👋 Was just wondering how do you structure your protobuf repos? Based on some articles [1][2] and stack overflow questions looks like people are leaning towards a monorepo approach but that also means that there is a potential disconnect between the schema and actual server implementation (which can run using older definitions). Guess that it is probably less troublesome than the alternatives....

Maybe give some thoughts to a monorepo approach, if that's an option

Has anyone worked with the new option to generate Kotlin code in Protobuf? Any impressions on it? I just looked at their docs and it looks rather weird, going to generate some code soon to check it out, but, yeah, looks weird, just like the Java code looks weird too. 😞

Are there here right people to tell them, that I would love gRPC for koltin-multiplatform? I have frontend running on node.js and backend on jvm.

The best place to start a discussion on that would most likely be the grpc-kotlin GitHub issues (edit: there's already one: https://github.com/grpc/grpc-kotlin/issues/51)

Hi! I'm pretty knew to Kotlin coroutines and gRPC, my server code is generated with grpc/grpc-kotlin and I struggle a bit to understand how I can even use the first coroutine explained in Kotlin's documentation in my gRPC server. Say I have the following server method (from the Kotlin gRPC Quick start):

private class HelloWorldService : GreeterGrpcKt.GreeterCoroutineImplBase() {
    override suspend fun sayHello(request: HelloRequest) = helloReply {}
}

And I want to write the following code at the beginning of this method (from Kotlin's documentation):

launch {
    delay(1000L)
    println("World!")
}
println("Hello")

If I simply copy-paste this code in my method,

launch

isn't recognized as a valid method because it should by used on a coroutine scope. If I wrap my code with a

coroutineScope

like this:

override suspend fun sayHello(request: HelloRequest) = coroutineScope {
    launch {
        delay(1000L)
        println("World!")
    }
    println("Hello")

    helloReply {}
}

It builds, the code is even executed when I make a call from the client, however the server returns an

UNKNOWN

code before the

launch

job can even finish and the

HelloReply

is not used. So I think I shouldn't create my own coroutine scope and I should use a scope already defined by the server, but I don't find anything related to a "default gRPC coroutine scope" in the API reference. I must be missing something really obvious, can someone help me run this really basic code please? 🙏

Hi! Does someone have a minimal setup to gradle kotlin grpc? I tried this https://github.com/grpc/grpc-kotlin/blob/master/compiler/README.md but it doesn’t work because it miss coroutines depedency and also I have this error

@io.grpc.stub.annotations.GrpcGenerated

^

symbol:   class GrpcGenerated

location: package io.grpc.stub.annotations

Guys, can I use the lib

grpc-kotlin

for web projects?

Hey y'all. I notice the stubs generated have the headers as an optional parameter to the service method. I really want to send response headers/trailers from the stub code. It seems like the way is via interceptors and threadlocals and coroutineContexts so that mutable things in the threadlocal get updated. That seems really painful to just add a response header. Am I missing something to have my stubbs return a Pair of <RESP, Metadata> ?

I did the threadlocal version. I added an AtmonicReference<String> as a threadLocal/contextElement. In the stubb, I get the Threadlocal and set the value. In the interceptor, I get the threadLocal then get the value and set it. But.. That's a lot of pain, and I'm not even sure the "post interceptor" is even running on the same thread after the "stub service method" runs.

Is there any decent documentation on how to create a gRPC request? It seems like everything uses the DSL stuff which I can't find any documentation for and isn't particularly intuitive:

val request = rectangle {
            lo = point(lowLat, lowLon)
            hi = point(hiLat, hiLon)
        }
        var i = 1
        stub.listFeatures(request).

☝️ that looks easy in theory but try it with a nontrivial request and it becomes near impossible to come up with the right syntax. Seems like sometimes things are a "DSL code block" and other time they're done like constructors? It would be nice if I could just construct the request like a

data class

instead of all this stuff

as an example how would I build this?

message DateRange {
  // The beginning of the date range
  google.type.Date from = 1 [(validate.rules).message.required = true];

  // The end of the date range
  google.type.Date until = 2 [(validate.rules).message.required = true];
}

Hi @everybody

Anyone have experience with Kotlin-gRPC?

Question: right now my application (which includes gRPC code) builds fine from the command-line (

gradlew bootJar

). Can build, run, everything works fine.

Yet IntelliJ is showing compile errors for some of the generated gRPC code. Has anyone experienced this?

If this is true, all the fields in the data model are platform types, which means no null safety unless you explicitly cast each one of them to a nullable type -- which is pretty bad for null safety. If Java is what's generated it would be nice if it at least marked everything nullable with an annotation (https://kotlinlang.org/docs/java-interop.html#nullability-annotations) just so Kotlin has some idea what to do. Ideally it would be nice if it actually generated Kotlin instead of Java; maybe it does but I'm not seeing it?