otel4s instrumentation for fs2-grpc.

• Integrates otel4s tracing with fs2-grpc ClientAspect and ServiceAspect
• Propagates context through gRPC metadata

This repository is no longer the recommended source for the integration.

Use fs2-grpc-otel4s-trace from typelevel/fs2-grpc. While it remains unreleased there, consume the snapshot published from that repository.

The last artifact published from this archived repository was:

libraryDependencies += "io.github.irevive" %% "fs2-grpc-otel4s-trace" % "0.4.0-R1"

The API shown below reflects the tracing integration now maintained in fs2-grpc.

The example wires the trace aspects into a generated fs2-grpc service. TestService denotes your service implementation.

import org.typelevel.fs2grpc.trace.*

def tracedService(using TracerProvider[IO]): Resource[IO, ServerServiceDefinition] =
  for {
    serviceAspect <- Resource.eval(TraceServiceAspect.create[IO])
    dispatcher    <- Dispatcher.parallel[IO]
  } yield TestServiceFs2Grpc.serviceFull(dispatcher, new TestService, serviceAspect, ServerOptions.default)

def tracedClient(channel: Channel)(using TracerProvider[IO]): Resource[IO, TestServiceFs2Grpc[IO, Metadata]] =
  for {
    clientAspect <- Resource.eval(TraceClientAspect.create[IO])
    dispatcher   <- Dispatcher.parallel[IO]
  } yield TestServiceFs2Grpc.mkClientFull(dispatcher, channel, clientAspect, ClientOptions.default)

TraceClientAspect and TraceServiceAspect expose a Config that can be refined before creation.

• withTracerName selects the tracer acquired from the provided TracerProvider.
• withTextMapUpdater / withTextMapGetter adjust metadata injection - default ASCII key.
• withSpanName and withAttributes override naming and attributes - defaults use the gRPC method descriptor and RPC semantic conventions.
• withFinalizationStrategy sets the SpanFinalizer.Strategy - defaults to reportAbnormal.