scala and akka-http

[antosha417]

Hi!
I have troubles using auto instrumentation with scala and akka-http. Is it supported?
I'm using java instrumentation 1.14.0

I would appreciate if you could take a look.

This is what I tried (click to expand)

I created a new akka-http project as suggested in docs

$ sbt new akka/akka-http-quickstart-scala.g8

Then I got generated code with these versions:

scalaVersion                  = "2.13.4"
akkaHttpVersion               = "10.2.9"
akkaVersion                   = "2.6.19"

Then I ran it with environment variables:

$ export JAVA_OPTS="-javaagent:/Users/antosha417/opentelemetry-javaagent.jar"
$ export OTEL_TRACES_EXPORTER=logging
$ export OTEL_METRICS_EXPORTER=none
$ export OTEL_LOGS_EXPORTER=none
$ export OTEL_SERVICE_NAME=testservicename
$ sbt run
[main] INFO io.opentelemetry.javaagent.tooling.VersionLogger - 
opentelemetry-javaagent - version: 1.14.0
[main] INFO io.opentelemetry.javaagent.tooling.VersionLogger - 
opentelemetry-javaagent - version: 1.14.0
...
[info] [2022-05-31 00:00:54,363] [INFO] [akka.actor.typed.ActorSystem] 
[HelloAkkaHttpServer akka.actor.default-dispatcher-6] [] - 
Server online at http://127.0.0.1:8080/

When I send get request to http://127.0.0.1:8080/users I expect to see spans in the terminal. But I see nothing 😿

I did exactly the same but with the java template and it works.

$ sbt new akka/akka-http-quickstart-java.g8

[antosha417]

I managed to get it working 🎉

I ended up using sbt-javaagent plugin to pass opentelemetry-javaagent.jar.
So now my build.sbt look like this:

lazy val root = (project in file("."))
  .settings(
    inThisBuild(
      List(
        organization := "com.example",
        scalaVersion := "2.13.4"
      )
    ),
    name := "akka-http-scala",
    libraryDependencies ++= Seq(
      "com.typesafe.akka" %% "akka-http" % akkaHttpVersion,
      "com.typesafe.akka" %% "akka-http-spray-json" % akkaHttpVersion,
      "com.typesafe.akka" %% "akka-actor-typed" % akkaVersion,
      "com.typesafe.akka" %% "akka-stream" % akkaVersion,
      "ch.qos.logback" % "logback-classic" % "1.2.3",
      "com.typesafe.akka" %% "akka-http-testkit" % akkaHttpVersion % Test,
      "com.typesafe.akka" %% "akka-actor-testkit-typed" % akkaVersion % Test,
      "org.scalatest" %% "scalatest" % "3.1.4" % Test
    ),
    javaAgents += "io.opentelemetry.javaagent" % "opentelemetry-javaagent" % "1.14.0" % "runtime"
  )
  .enablePlugins(JavaAgent)