Use external prom server

.github/workflows/test.yaml

@@ -35,10 +35,12 @@ jobs:
 
       - name: Install System Libs
         run: sudo apt-get install -y openssl libapr1
+
       - name: Setup gradle
         uses: gradle/gradle-build-action@v2
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Check
         run: make test
         env:

build.gradle

@@ -71,6 +71,7 @@ dependencies {
     implementation(libs.reactor.grpc.stub)
     implementation(libs.grpc.proto.util)
 
+    implementation libs.prom.exporter.server
     implementation libs.micrometer.registry.prometheus
     implementation libs.micrometer.ctx.prop
     implementation libs.lettuce.core

gradle/libs.versions.toml

@@ -61,6 +61,7 @@ kotlin-reflect = { module = "org.jetbrains.kotlin:kotlin-reflect", version.ref =
 
 lettuce-core = "io.lettuce:lettuce-core:5.2.2.RELEASE"
 
+prom-exporter-server = "io.prometheus:prometheus-metrics-exporter-httpserver:1.5.0"
 micrometer-registry-prometheus = "io.micrometer:micrometer-registry-prometheus:1.16.0"
 micrometer-ctx-prop = "io.micrometer:context-propagation:1.2.0"
 
@@ -104,7 +105,7 @@ spring-boot-starter-actuator = { module = "org.springframework.boot:spring-boot-
 
 spring-boot-starter-test = { module = "org.springframework.boot:spring-boot-starter-test", version.ref = "spring-boot" }
 
-testcontainers = "org.testcontainers:testcontainers:1.21.3"
+testcontainers = "org.testcontainers:testcontainers:2.0.3"
 testcontainers-ganache = "io.github.ganchix:testcontainers-java-module-ganache:0.0.4"
 
 assertj = "org.assertj:assertj-core:3.23.1"

src/main/kotlin/io/emeraldpay/dshackle/Starter.kt

@@ -42,14 +42,6 @@ fun main(args: Array<String>) {
     Hooks.enableAutomaticContextPropagation()
     OpenSsl.ensureAvailability()
 
-    if (!System.getProperties().containsKey("sun.net.httpserver.maxReqTime")) {
-        System.setProperty("sun.net.httpserver.maxReqTime", "60")
-    }
-
-    if (!System.getProperties().containsKey("sun.net.httpserver.maxRspTime")) {
-        System.setProperty("sun.net.httpserver.maxRspTime", "600")
-    }
-
     // add metrics for internal reactor schedulers
     Schedulers.addExecutorServiceDecorator("key") { scheduler, execService ->
         val schedulerName = Scannable.from(scheduler).scanOrDefault(Attr.NAME, scheduler.javaClass.name)

src/main/kotlin/io/emeraldpay/dshackle/monitoring/MonitoringSetup.kt

@@ -15,7 +15,6 @@
  */
 package io.emeraldpay.dshackle.monitoring
 
-import com.sun.net.httpserver.HttpServer
 import io.emeraldpay.dshackle.Global
 import io.emeraldpay.dshackle.config.MonitoringConfig
 import io.micrometer.core.instrument.Meter
@@ -28,19 +27,10 @@ import io.micrometer.core.instrument.binder.system.ProcessorMetrics
 import io.micrometer.core.instrument.config.MeterFilter
 import io.micrometer.prometheusmetrics.PrometheusConfig
 import io.micrometer.prometheusmetrics.PrometheusMeterRegistry
+import io.prometheus.metrics.exporter.httpserver.HTTPServer
 import jakarta.annotation.PostConstruct
 import org.slf4j.LoggerFactory
 import org.springframework.stereotype.Service
-import java.io.IOException
-import java.net.InetAddress
-import java.net.InetSocketAddress
-import java.net.ServerSocket
-import java.nio.charset.StandardCharsets
-import java.util.concurrent.Executors
-import java.util.concurrent.ThreadFactory
-import java.util.concurrent.TimeUnit
-import java.util.concurrent.atomic.AtomicInteger
-import java.util.zip.GZIPOutputStream
 
 @Service
 class MonitoringSetup(
@@ -51,20 +41,6 @@ class MonitoringSetup(
         private val log = LoggerFactory.getLogger(MonitoringSetup::class.java)
     }
 
-    private fun isTcpPortAvailable(host: String, port: Int): Boolean {
-        try {
-            ServerSocket().use { serverSocket ->
-                // setReuseAddress(false) is required only on macOS,
-                // otherwise the code will not work correctly on that platform
-                serverSocket.reuseAddress = false
-                serverSocket.bind(InetSocketAddress(InetAddress.getByName(host), port), 1)
-                return true
-            }
-        } catch (ex: java.lang.Exception) {
-            return false
-        }
-    }
-
     @PostConstruct
     fun setup() {
         val prometheusRegistry = PrometheusMeterRegistry(PrometheusConfig.DEFAULT)
@@ -93,77 +69,13 @@ class MonitoringSetup(
         }
 
         if (monitoringConfig.prometheus.enabled) {
-            // use standard JVM server with a single thread blocking processing
-            // prometheus is a single thread periodic call, no reason to setup anything complex
-            Thread {
-                var started = false
-                val scrapeThreadCounter = AtomicInteger(0)
-                val scrapeExecutor = Executors.newFixedThreadPool(
-                    4,
-                    ThreadFactory { runnable ->
-                        Thread(runnable, "prometheus-scrape-${scrapeThreadCounter.incrementAndGet()}").apply {
-                            isDaemon = true
-                        }
-                    },
-                )
-                while (true) {
-                    if (isTcpPortAvailable(monitoringConfig.prometheus.host, monitoringConfig.prometheus.port)) {
-                        started = true
-                        try {
-                            log.info("Run Prometheus metrics on ${monitoringConfig.prometheus.host}:${monitoringConfig.prometheus.port}${monitoringConfig.prometheus.path}")
-                            val server = HttpServer.create(
-                                InetSocketAddress(
-                                    monitoringConfig.prometheus.host,
-                                    monitoringConfig.prometheus.port,
-                                ),
-                                0,
-                            )
-                            server.executor = scrapeExecutor
-                            server.createContext(monitoringConfig.prometheus.path) { httpExchange ->
-                                val startTime = System.nanoTime()
-                                try {
-                                    val response = prometheusRegistry.scrape()
-                                    val responseBytes = response.toByteArray(StandardCharsets.UTF_8)
-                                    httpExchange.responseHeaders.add("Content-Encoding", "gzip")
-                                    httpExchange.responseHeaders.add("Content-Type", "text/plain; version=0.0.4; charset=utf-8")
-                                    httpExchange.sendResponseHeaders(200, 0)
-                                    httpExchange.responseBody.use { os ->
-                                        GZIPOutputStream(os).use { gzos ->
-                                            gzos.write(responseBytes)
-                                        }
-                                    }
-                                    val durationMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startTime)
-                                    if (durationMs > 5000) {
-                                        log.warn("Prometheus scrape served in {} ms", durationMs)
-                                    } else {
-                                        log.debug("Prometheus scrape served in {} ms", durationMs)
-                                    }
-                                } catch (e: Exception) {
-                                    log.error("Failed to serve Prometheus metrics", e)
-                                    val messageBytes = "internal error".toByteArray(StandardCharsets.UTF_8)
-                                    runCatching {
-                                        httpExchange.responseHeaders.add("Content-Type", "text/plain; charset=utf-8")
-                                        httpExchange.sendResponseHeaders(500, messageBytes.size.toLong())
-                                        httpExchange.responseBody.use { os ->
-                                            os.write(messageBytes)
-                                        }
-                                    }
-                                } finally {
-                                    httpExchange.close()
-                                }
-                            }
-                            Thread(server::start).start()
-                        } catch (e: IOException) {
-                            log.error("Failed to start Prometheus Server", e)
-                        }
-                    } else {
-                        if (!started) {
-                            log.error("Can't start prometheus metrics on ${monitoringConfig.prometheus.host}:${monitoringConfig.prometheus.port}${monitoringConfig.prometheus.path}")
-                        }
-                        Thread.sleep(1000)
-                    }
-                }
-            }.start()
+            HTTPServer
+                .builder()
+                .hostname(monitoringConfig.prometheus.host)
+                .port(monitoringConfig.prometheus.port)
+                .registry(prometheusRegistry.prometheusRegistry)
+                .metricsHandlerPath(monitoringConfig.prometheus.path)
+                .buildAndStart()
         }
     }
 }