jonasheylen / opentracing-scala

opentracing-scala

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

---

Tracing monad is defined over type constructor T[_[*], *], that wraps the underlying monad. But its interface is separated into two typeclasses.

Traced[F[_]] ignores underlying type constructor and defines most operations:

  def apply[A](op: String, tags: Traced.Tag*)(fa: F[A]): F[A]
  def spanResource(op: String, tags: Traced.Tag*): Resource[F, ActiveSpan]
    
  def pure[A](a: A): F[A]
  def defer[A](fa: => F[A]): F[A]
  
  def currentSpan: Traced.SpanInterface[F]
  
  def injectContext(context: SpanContext): Traced.Interface[F]
  def injectContextFrom[C](carrier: C, format: Format[C]): Traced.Interface[F]
  
  def extractContext[C0 <: C, C](carrier: C0, format: Format[C]): F[Option[C0]] 

Traced2[T[_[*], *], F[_]] refines operations, that require knowing underlying functor:

  def currentRunParams: F[U, Traced.RunParams]
  def run[A](traced: F[U, A], params: Traced.RunParams): U[A]
  
  def lift[A](ua: U[A]): F[U, A]
  def mapK[G[_]](f: U ~> G): F[U, *] ~> F[G, *]

Traced Transformer

Implementation using cats' state transformer.

  type TracedT[F[_], A] = StateT[F, State, A]

Provides (experimental) instances of Sync and ConcurrentEffect.

opentracing-jaeger-scalac-implicits

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

Usage

• Put to your build.sbt

  addCompilerPlugin("com.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