Example Kotlin Vert.x tcp server with prometheus metrics

example-kotlin-vertx-tcp-prometheus.kt

fun main() {
  // init prometheus registry
  val registry = PrometheusMeterRegistry(PrometheusConfig.DEFAULT)
  // bind micrometer metrics
  ClassLoaderMetrics().bindTo(registry)
  JvmMemoryMetrics().bindTo(registry)
  JvmGcMetrics().bindTo(registry)
  ProcessorMetrics().bindTo(registry)
  JvmThreadMetrics().bindTo(registry)
  UptimeMetrics().bindTo(registry)
  FileDescriptorMetrics().bindTo(registry)

  // create custom counter metric for packets received
  Counter.builder("packets.received")
    .description("number of reports added")
    .baseUnit(BaseUnits.TASKS)
    .register(registry)

  // set up vertx options to report tcp metrics and start an embedded http server on port 9999
  val vertxOptions = VertxOptions().setMetricsOptions(
    MicrometerMetricsOptions()
      .setPrometheusOptions(
        VertxPrometheusOptions().setEnabled(true)
          .setStartEmbeddedServer(true)
          .setEmbeddedServerOptions(HttpServerOptions().setPort(9999))
          .setEmbeddedServerEndpoint("/metrics")
      )
      .setMicrometerRegistry(registry)
      .setEnabled(true)
  )

  val vertx = Vertx.vertx(vertxOptions)
  // start our tcp server
  vertx.createNetServer().connectHandler { it.handler { registry.counter("packets.received").increment() } }
    .listen(9091)
}