WeatherApi.scala

package net.gutefrage

import com.twitter.finagle._
import com.twitter.finagle.http.service.HttpResponseClassifier
import com.twitter.server.TwitterServer
import com.twitter.util.Await
import io.finch._
import io.finch.circe._
import io.circe.generic.auto._
import net.gutefrage.temperature.thrift._

/**
  * Serves the mean temperature at `/weather/mean`
  */
object WeatherApi extends TwitterServer {

  def main(): Unit = {
  
    val client = ThriftMux.client.newIface[TemperatureService.FutureIface](
      "zk!127.0.0.1:2181!/service/temperature",  "weather-api-client")

    /** json model */
    case class Mean(mean: Double)

    // mean temperature endpoint
    val api: Endpoint[Mean] = get("weather" / "mean") {
      client.mean().map(mean => Ok(Mean(mean)))
    }

    // start and announce the server
    val server = Http.server
      .withLabel("weather-api")
      // 5xx response should be classified as server errors
      .withResponseClassifier(HttpResponseClassifier.ServerErrorsAsFailures)
      .serveAndAnnounce(
        name = "zk!127.0.0.1:2181/service/weather!0",
        addr = s":8080",
        service = api.toService
      )

    closeOnExit(server)
    Await.ready(server)
  }
}