Functional interface for opentracing and its implementation, based on cats.data.StateT.

Requires cats-effect 3.

Supports scala 2.12, 2.13 and 3.1.

Code

• Lifting values and effects through pure and defer.
• Creating new spans (extends Traced.Interface[F])

    def apply[A](op: String, tags: Traced.Tag*)(fa: F[A]): F[A]
    def spanResource(op: String, tags: Traced.Tag*): Resource[F, ActiveSpan]

    def withParent(span: ActiveSpan | SpanContext): Interface[F]
    def withoutParent: Interface[F]

• Accessing currentSpan through Traced.SpanInterface[F]

    def context: F[Option[SpanContext]]

    def setOperation(op: String): F[Unit]
    def setTag(tag: Traced.Tag): F[Unit]
    def setTags(tags: Traced.Tag*): F[Unit]

    def log(fields: (String, Any)*): F[Unit]
    def log(event: String): F[Unit]

    def setBaggageItem(key: String, value: String): F[Unit]
    def getBaggageItem(key: String): F[Option[String]]

• Setting current span

  def forceCurrentSpan(active: Traced.ActiveSpan): F[Traced.SpanInterface[F]]
  /** Sets `active` span if no other is set. */
  def recoverCurrentSpan(active: Traced.ActiveSpan): F[Traced.SpanInterface[F]]

• Transferring span context

  def injectContext(context: SpanContext): Traced.Interface[F]
  def injectContextFrom(carrier: Propagation#Carrier): Traced.Interface[F]
  def extractContext[C <: Propagation#Carrier](carrier: C): F[Option[C]]

extends Traced[T[F, _]]

Defines tracing over transformer T[F, _], allowing to run and lift T[F, _] <~> F

  def currentRunParams: T[F, Traced.RunParams]
  def run[A](traced: T[F, A], params: Traced.RunParams): F[A]

  def lift[A](ua: F[A]): T[F, A]
  def mapK[G[_]](f: F ~> G): T[F, _] ~> T[G, _]

Running the transformer requires

• currently active span
• setup
  • tracer
  • beforeStart, justAfterStart, beforeStop hooks (Traced.Hooks)
  • error logger

Default setups can be obtained at Traced.Setup.default(_: Tracer) or

• Jaeger (in opentracing-scala-jaeger) module
• NoOp (in opentracing-scala-noop) module

Support for

• BinaryPropagation
• TextMapPropagation

import io.github.fehu.opentracing.syntax._

TODO

Traced transformer implementation with underlying cats.data.StateT.

Provides instances of most cats.effect typeclasses and a Dispatcher for TracedT[IO, A].

Other modules:

• opentracing-scala-akka - TracingActor and ask(actor, message).trace(...) syntax.
• opentracing-scala-fs2 - Syntax extensions for fs2 at io.github.fehu.opentracing.syntax.FS2.
• opentracing-scala-jaeger - Setup helper for io.jaegertracing.
• opentracing-scala-noop - No-op setup.

Compiler plugin that traces implicit searches performed by scalac and reports them to local jaegertracing backend.

• Put to your build.sbt

  addCompilerPlugin("io.github.fehu" %% "opentracing-jaeger-scalac-implicits" % "0.1.3")
  

• Run, for example, all-in-one jaeger backend with docker
• Compile your project
• See the traces at http://localhost:16686