stupid.scala

//> using scala "2.13"
//> using lib "com.armanbilge::bayou:0.1-4fb42c8"
//> using lib "org.typelevel::cats-effect:3.3.7"
//> using lib "co.fs2::fs2-core:3.2.5"
//> using lib "org.typelevel::log4cats-core:2.2.0"
//> using lib "org.typelevel::log4cats-slf4j:2.2.0"
//> using lib "org.tpolecat::natchez-core:0.1.6"
//> using lib "org.tpolecat::natchez-log:0.1.6"

import cats.effect.{Trace => _, _}
import cats.implicits._
import fs2._
import bayou.Trace
import bayou.Trace._
import natchez.log.Log
import natchez.{Trace => _, _}
import org.typelevel.log4cats.Logger
import org.typelevel.log4cats.slf4j.Slf4jLogger
import scala.concurrent.duration._
import scala.concurrent.ExecutionContext.global
import java.net.URI

trait Setup {

  val entryPoint = Log.entryPoint[IO]("example")

  val trace = entryPoint.root("root").flatMap(r => Resource.eval(Trace.ioTrace(r)))

  implicit def logger: Logger[IO] =
    new Logger[IO] {
      def error(message: => String): IO[Unit] =
        IO.println(s"[error] $message\n")
      def warn(message: => String): IO[Unit] =
        IO.println(s"[warn] $message\n")
      def info(message: => String): IO[Unit] =
        IO.println(s"[info] $message\n")
      def debug(message: => String): IO[Unit] =
        IO.println(s"[debug] $message\n")
      def trace(message: => String): IO[Unit] =
        IO.println(s"[trace] $message\n")
      def error(t: Throwable)(message: => String): IO[Unit] =
        IO.println(s"[error] $message\n${t.getMessage}")
      def warn(t: Throwable)(message: => String): IO[Unit] =
        IO.println(s"[warn] $message\n${t.getMessage}")
      def info(t: Throwable)(message: => String): IO[Unit] =
        IO.println(s"[info] $message\n${t.getMessage}")
      def debug(t: Throwable)(message: => String): IO[Unit] =
        IO.println(s"[debug] $message\n${t.getMessage}")
      def trace(t: Throwable)(message: => String): IO[Unit] =
        IO.println(s"[trace] $message\n${t.getMessage}")
  }
}

object Single extends IOApp.Simple with Setup {
  def run: IO[Unit] = {
    trace.use { implicit trace =>
      for {
        a <- trace.spanR("a").allocated
        b <- trace.spanR("b").allocated
        _ <- trace.put("1" -> "1")
        _ <- a._2
        _ <- trace.put("2" -> "2")
        _ <- b._2
        _ <- trace.put("3" -> "3")
      } yield ()
    }
  }
}

trace.json

{
  "name" : "root",
  "service" : "example",
  "timestamp" : "2022-03-09T01:45:00.675Z",
  "duration_ms" : 213,
  "trace.span_id" : "4493b161-624c-487a-9df7-7e348090331f",
  "trace.parent_id" : null,
  "trace.trace_id" : "d373716f-afcf-4f3b-8b89-3a49487c48d2",
  "exit.case" : "succeeded",
  "2" : "2",
  "children" : [
    {
      "name" : "a",
      "service" : "example",
      "timestamp" : "2022-03-09T01:45:00.691Z",
      "duration_ms" : 136,
      "trace.span_id" : "0c951942-0a20-48ee-8756-148639a7cd79",
      "trace.parent_id" : "d373716f-afcf-4f3b-8b89-3a49487c48d2",
      "trace.trace_id" : "d373716f-afcf-4f3b-8b89-3a49487c48d2",
      "exit.case" : "succeeded",
      "children" : [
      ]
    }
  ]
}