Add fs2-grpc-otel4s-trace module

.github/workflows/ci.yml

@@ -87,11 +87,11 @@ jobs:
 
       - name: Make target directories
         if: github.event_name != 'pull_request' && (startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main')
-        run: mkdir -p plugin/target runtime/target/jvm-2.12 codegen/target/jvm-3 codegen/target/jvm-2.13 runtime/target/jvm-3 codegen/target/jvm-2.12 runtime/target/jvm-2.13 project/target
+        run: mkdir -p plugin/target otel4s-trace/target/jvm-3 runtime/target/jvm-2.12 codegen/target/jvm-3 codegen/target/jvm-2.13 runtime/target/jvm-3 codegen/target/jvm-2.12 runtime/target/jvm-2.13 otel4s-trace/target/jvm-2.13 project/target
 
       - name: Compress target directories
         if: github.event_name != 'pull_request' && (startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main')
-        run: tar cf targets.tar plugin/target runtime/target/jvm-2.12 codegen/target/jvm-3 codegen/target/jvm-2.13 runtime/target/jvm-3 codegen/target/jvm-2.12 runtime/target/jvm-2.13 project/target
+        run: tar cf targets.tar plugin/target otel4s-trace/target/jvm-3 runtime/target/jvm-2.12 codegen/target/jvm-3 codegen/target/jvm-2.13 runtime/target/jvm-3 codegen/target/jvm-2.12 runtime/target/jvm-2.13 otel4s-trace/target/jvm-2.13 project/target
 
       - name: Upload target directories
         if: github.event_name != 'pull_request' && (startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main')
@@ -224,7 +224,7 @@ jobs:
       - name: Submit Dependencies
         uses: scalacenter/sbt-dependency-submission@v2
         with:
-          modules-ignore: root_3 e2e_2.12 e2e_3 e2e_2.13
+          modules-ignore: root_3 e2e_2.12 e2eotel4s_3 e2eotel4s_2.13 e2e_3 e2e_2.13
           configs-ignore: test scala-tool scala-doc-tool test-internal
 
   validate-steward:

README.md

@@ -126,6 +126,51 @@ The full set of options available are:
 PB.protocOptions in Compile := Seq("-xyz")
 ```
 
+## OpenTelemetry tracing with otel4s
+
+The `fs2-grpc-otel4s-trace` module provides client and service aspects for tracing with [otel4s](https://typelevel.org/otel4s/).
+The default configuration follows the OpenTelemetry gRPC semantic conventions for span kind, span name,
+`rpc.system.name`, `rpc.method`, and `rpc.response.status_code`.
+
+```scala
+import cats.effect.IO
+import fs2.grpc.otel4s.trace.{TraceClientAspect, TraceServiceAspect}
+import io.grpc.Metadata
+import org.typelevel.otel4s.trace.TracerProvider
+
+def clientAspect(implicit tracerProvider: TracerProvider[IO]) =
+  TraceClientAspect.create[IO]
+
+def serviceAspect(implicit tracerProvider: TracerProvider[IO]) =
+  TraceServiceAspect.create[IO]
+```
+
+Use `withServerAddress` when the logical server address is known. The aspect cannot infer it from the generated call
+context:
+
+```scala
+val clientConfig =
+  TraceClientAspect.Config.default
+    .withServerAddress("grpc.example.com", Some(443))
+
+val serviceConfig =
+  TraceServiceAspect.Config.default
+    .withServerAddress("grpc.example.com", Some(443))
+```
+
+Other defaults can be customized through `Config`, for example span names, metadata propagation, attributes, and
+finalization.
+
+```scala
+val clientConfig =
+  TraceClientAspect.Config.default
+    .withTracerName("my-client")
+    .withSpanName((_, ctx) => ctx.methodDescriptor.getFullMethodName)
+```
+
+See the [OpenTelemetry gRPC semantic conventions](https://opentelemetry.io/docs/specs/semconv/rpc/grpc/) for the
+attribute definitions.
+
 ### Tool Sponsorship
 
 <img width="185px" height="44px" align="right" src="https://www.yourkit.com/images/yklogo.png"/>Development of fs2-grpc is generously supported in part by [YourKit](https://www.yourkit.com) through the use of their excellent Java profiler.

build.sbt

@@ -53,7 +53,8 @@ inThisBuild(
 )
 
 lazy val projects =
-  runtime.projectRefs ++ codegen.projectRefs ++ e2e.projectRefs ++ List(plugin.project, protocGen.agg.project)
+  runtime.projectRefs ++ otel4sTrace.projectRefs ++ codegen.projectRefs ++ e2e.projectRefs ++ e2eOtel4s.projectRefs ++
+    List(plugin.project, protocGen.agg.project)
 
 lazy val root = (project in file("."))
   .enablePlugins(BuildInfoPlugin, NoPublishPlugin)
@@ -112,6 +113,7 @@ lazy val plugin = project
 
 lazy val runtime = (projectMatrix in file("runtime"))
   .defaultAxes(axesDefault: _*)
+  .enablePlugins(BuildInfoPlugin)
   .settings(
     name := "fs2-grpc-runtime",
     tlVersionIntroduced := Map("2.12" -> "2.5.3", "2.13" -> "2.5.3", "3" -> "2.5.3"),
@@ -124,10 +126,32 @@ lazy val runtime = (projectMatrix in file("runtime"))
     scalacOptions ++= {
       if (tlIsScala3.value) { Seq("-language:implicitConversions", "-Ykind-projector", "-source:3.0-migration") }
       else Seq.empty
-    }
+    },
+    buildInfoPackage := "fs2.grpc",
+    buildInfoKeys := Seq[BuildInfoKey](version),
+    buildInfoOptions += BuildInfoOption.PackagePrivate
   )
   .jvmPlatform(scalaVersions = Seq(Scala212, Scala213, Scala3))
 
+lazy val otel4sTrace = (projectMatrix in file("otel4s-trace"))
+  .dependsOn(runtime)
+  .defaultAxes(axesDefault: _*)
+  .settings(
+    name := "fs2-grpc-otel4s-trace",
+    tlVersionIntroduced := Map("2.13" -> "3.1.0", "3" -> "3.1.0"),
+    libraryDependencies ++= List(otel4sCoreTrace, otel4sSemconv) ++ List(grpcNetty, ceTestkit, ceMunit).map(_ % Test),
+    Test / parallelExecution := false,
+    scalacOptions := {
+      if (tlIsScala3.value) { scalacOptions.value.filterNot(_ == "-Ykind-projector:underscores") }
+      else scalacOptions.value
+    },
+    scalacOptions ++= {
+      if (tlIsScala3.value) { Seq("-language:implicitConversions", "-Ykind-projector", "-source:3.0-migration") }
+      else Seq.empty
+    }
+  )
+  .jvmPlatform(scalaVersions = Seq(Scala213, Scala3))
+
 lazy val codeGenJVM212 = codegen.jvm(Scala212)
 lazy val protocGen = protocGenProject("protoc-gen-fs2-grpc", codeGenJVM212)
   .settings(
@@ -194,3 +218,36 @@ lazy val e2e = (projectMatrix in file("e2e"))
     }
   )
   .jvmPlatform(scalaVersions = Seq(Scala212, Scala213, Scala3))
+
+lazy val e2eOtel4s = (projectMatrix in file("e2e-otel4s"))
+  .dependsOn(runtime, otel4sTrace)
+  .defaultAxes(axesDefault: _*)
+  .enablePlugins(LocalCodeGenPlugin, NoPublishPlugin)
+  .settings(
+    codeGenClasspath := (codeGenJVM212 / Compile / fullClasspath).value,
+    libraryDependencies := Nil,
+    libraryDependencies ++= List(
+      scalaPbGrpcRuntime,
+      scalaPbRuntime,
+      scalaPbRuntime % "protobuf",
+      ceMunit % Test,
+      otel4sOtelJavaTestkit % Test,
+      otel4sSemconvExperimental % Test,
+      "io.grpc" % "grpc-inprocess" % versions.grpc % Test
+    ),
+    Compile / PB.targets := Seq(
+      scalapb.gen() -> (Compile / sourceManaged).value / "scalapb",
+      genModule(codegenFullName + "$") -> (Compile / sourceManaged).value / "fs2-grpc"
+    ),
+    githubWorkflowArtifactUpload := false,
+    scalacOptions := {
+      if (tlIsScala3.value) {
+        scalacOptions.value.filterNot(o => o == "-Ykind-projector:underscores" || o == "-Wvalue-discard")
+      } else scalacOptions.value
+    },
+    scalacOptions ++= {
+      if (tlIsScala3.value) { Seq("-language:implicitConversions", "-Ykind-projector", "-source:3.0-migration") }
+      else Seq.empty
+    }
+  )
+  .jvmPlatform(scalaVersions = Seq(Scala213, Scala3))

e2e-otel4s/src/main/protobuf/test_service.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+
+package hello.world;
+
+// TestService: Example gRPC service used in e2e tests
+// It demonstrates all four RPC shapes.
+service TestService {
+  // Unary RPC: no streaming in either direction
+  rpc noStreaming (TestRequest) returns (TestResponse);
+  // Client streaming RPC: client streams, server returns a single response
+  rpc clientStreaming (stream TestRequest) returns (TestResponse);
+  // Server streaming RPC: client sends one request, server streams responses
+  rpc serverStreaming (TestRequest) returns (stream TestResponse);
+  // Bidirectional streaming RPC: both client and server stream
+  rpc bothStreaming (stream TestRequest) returns (stream TestResponse);
+}
+
+message TestRequest {}
+message TestResponse {}