ktor-metrics-extension

This ktor-metrics-extension is an extension library that exposes metrics collected using Kotor's MicroMeter at the default Prometheus endpoint.

Installation

Step 1. Add the JitPack repository to your build file

repositories {
    ...
    maven(url = "https://jitpack.io")
}

Step 2. Add the dependency

implementation("ch.qos.logback:logback-classic:$logbackVersion")
implementation("io.ktor:ktor-server-core:$ktorVersion")
implementation("io.ktor:ktor-metrics:$ktorVersion")
implementation("io.ktor:ktor-metrics-micrometer:$ktorVersion")
implementation("io.micrometer:micrometer-registry-prometheus:$micrometerVersion")
implementation("io.prometheus:simpleclient_httpserver:$prometheusVersion")
implementation("com.github.otkmnb2783:ktor-metrics-extension:<this_library_current_version>")

Usage

fun main(args: Array<String>): Unit = EngineMain.main(args)

@OptIn(KtorExperimentalLocationsAPI::class)
@Suppress("unused", "UNUSED_PARAMETER")
@kotlin.jvm.JvmOverloads
fun Application.module(testing: Boolean = false) {

    install(Locations) {
    }

    install(CallLogging) {
        level = Level.INFO
        filter { call -> call.request.path().startsWith("/") }
    }

    val prometheus = PrometheusMeterRegistry(PrometheusConfig.DEFAULT)

    install(MicrometerMetrics) {
        registry = prometheus
        distributionStatisticConfig = DistributionStatisticConfig.DEFAULT
        meterBinders = listOf(
            JvmMemoryMetrics(),
            JvmGcMetrics(),
            ProcessorMetrics(),
            JvmThreadMetrics()
        )
    }

    install(PrometheusExporterServer) {
        registry = prometheus
        runServer = true
    }

    routing {
        get("/") {
            call.respondText("HELLO WORLD!", contentType = ContentType.Text.Plain)
        }
    }
}

curl -XGET http://localhost:8080/metrics
curl -XGET http://localhost:9090/metrics