Http4sBlazeServerBuilder.scala

object Http4sBlazeServerBuilder {

  case class Server(fiber: Fiber[IO, Nothing]) {
    def shutdownNow(): Unit = fiber.cancel.unsafeRunSync()
  }
  type MappedService = (String, HttpRoutes[IO])

  private implicit val cs = IO.contextShift(ExecutionContext.Implicits.global)

  def startServer(port: Int,
                  monitoringOrdinals: Option[DevOpsController.FlowOrdinalF] = None)
                 (services: MappedService*): Server = {
    DevOpsMetrics.registerDefaultMetrics()

    val withPrometheusMetrics = PrometheusMetrics[IO](CollectorRegistry.defaultRegistry, prefix = "tmnow_http_server")

    val mappings: List[MappedService] = {
      ("/devops/internal", DevOpsController.createService(monitoringOrdinals)) ::
        services.toList
    }

    Server(
      BlazeServerBuilder[IO].
        bindHttp(port, "0.0.0.0").
        withIdleTimeout(5.minutes).
        withHttpApp(
          IORequestLogger(
            withPrometheusMetrics(
              Router[IO](mappings: _*)
            ).unsafeRunSync.orNotFound
          )
        ).
        resource.
        use(_ => IO.never).
        start.
        unsafeRunSync()
    )
  }

}