adamw

def addBookLogic(b: Book, authToken: String): Future[Either[Unit, Boolean]] = ...
val addBook: Endpoint[(Book, String), Unit, Boolean, Nothing] = ...

import tapir.server.akkahttp._
import akka.http.scaladsl.server.Route
val addBookRoute: Route = addBook.toRoute(addBookLogic _)

adamw

val findBook: Endpoint[String, Unit, Option[Book], Nothing] = 
  endpoint
    .get
    .in("book" / "find" / path[String])
    .out(jsonBody[Option[Book]])

adamw

val addBook: Endpoint[(Book, String), Unit, Boolean, Nothing] =
  endpoint
    .post
    .in("book" / "add")
    .in(jsonBody[Book])
    .in(header[String]("X-Auth-Token"))
    .out(plainBody[Boolean])

adamw

import tapir._
val addBook: Endpoint[(Book, String), Unit, Boolean, Nothing] =
  endpoint
    .in(jsonBody[Book])
    .in(header[String]("X-Auth-Token"))
    .out(plainBody[Boolean])

adamw

<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
  <encoder>
    <pattern>%d{HH:mm:ss.SSS} %highlight(%replace([%X{cid}] ){'\[\] ', ''})[%thread] %-5level %logger{5} - %msg%n</pattern>
  </encoder>

  <filter class="com.softwaremill.monix.SetCorrelationIdInMDCFilter" />
</appender>

adamw

class SetCorrelationIdInMDCFilter extends Filter[ILoggingEvent] {
  override def decide(event: ILoggingEvent): FilterReply = {
    CorrelationId().foreach(MDC.put("cid", _)) 
    FilterReply.NEUTRAL
  }
}

adamw

class SetCorrelationIdBackend(delegate: SttpBackend[Task, Nothing]) 
  extends SttpBackend[Task, Nothing] {
    
  override def send[T](request: sttp.Request[T, Nothing]): Task[Response[T]] = {
    // suspending the calculation of the correlation id until the request 
    // send is evaluated
    Task {
      CorrelationId() match {
        case Some(cid) => request.header(CorrelationIdHeader, cid)
        case None => request

adamw

object Server1 extends App with StrictLogging {
  val dsl = Http4sDsl[Task]
  import dsl._

  val service = HttpRoutes.of[Task] {
    case GET -> Root / "test1" => Ok()
  }

  BlazeServerBuilder[Task]
    .bindHttp(8081)

adamw

object CorrelationId {
  val CorrelationIdHeader = "X-Correlation-ID"
  
  def setCorrelationIdMiddleware(service: HttpRoutes[Task]): HttpRoutes[Task] = 
    Kleisli { req: Request[Task] =>
      val cid = req.headers.get(CaseInsensitiveString(CorrelationIdHeader)) match {
        case None => newCorrelationId()
        case Some(cidHeader) => cidHeader.value
      }

adamw

object CorrelationId extends StrictLogging {
  private val localCid = new Local[Option[String]](() => {
    None
  })

  def apply(): Option[String] = localCid()
}