zio-http-premetheus

zio-http.scala

import zio.http.*
import zio.http.service.*
import zio.metrics.connectors.prometheus.*
import zio.*
import zio.metrics.Metric
import zio.metrics.connectors.MetricsConfig
import zio.http.model.Method.GET

object Metrics extends ZIOAppDefault {

  def reqCounter(method: String, path: String) =
    Metric
      .counterInt("request-counter")
      .fromConst(1)
      .tagged("method", method)
      .tagged("path", path)

  private val appRoutes = Http.collectZIO[Request] {
    case GET -> !! / "metrics" => ZIO.serviceWithZIO[PrometheusPublisher](_.get.map(Response.text))
    case GET -> !! / "hit"     =>
      ZIO.succeed(
        Response.text("OK")
      ) @@ reqCounter("GET", "/hit")
  }

  val run = (for {
    ticker <- (ZIO.log("tick") @@ reqCounter("NA", "/tick")).schedule(Schedule.spaced(3.second)).fork
    _      <- ZIO.log("starting web application...")
    _      <- Server.serve(appRoutes) zipPar ticker.await
  } yield ())
    .provide(
      Server.live,
      ServerConfig.live(ServerConfig.default.port(9300)),
      publisherLayer,
      prometheusLayer,
      ZLayer.succeed(MetricsConfig(1.second))
    )
}

lazy val zioMetricsConnectors = zioOrg %% "zio-metrics-connectors" % "2.0.4"