Move metrics endpoint to separate server on :9090

Author: SIMULATAN

src/main/kotlin/me/snoty/backend/config/Config.kt

@@ -3,6 +3,7 @@ package me.snoty.backend.config
 data class Config(
 	val database: DatabaseConfig,
 	val port: Short = 8080,
+	val prometheusPort: Short = 9090,
 	val publicHost: String,
 	val environment: Environment,
 	val authentication: OidcConfig

src/main/kotlin/me/snoty/backend/server/KtorServer.kt

@@ -36,7 +36,7 @@ class KtorServer(
 	}
 
 	private fun Application.module() {
-		configureMonitoring(metricsRegistry)
+		configureMonitoring(config, metricsRegistry)
 		configureHTTP()
 		configureSecurity(config)
 		configureSerialization()

src/main/kotlin/me/snoty/backend/server/plugins/Monitoring.kt

@@ -2,17 +2,20 @@ package me.snoty.backend.server.plugins
 
 import io.ktor.http.*
 import io.ktor.server.application.*
+import io.ktor.server.engine.*
 import io.ktor.server.metrics.micrometer.*
+import io.ktor.server.netty.*
 import io.ktor.server.plugins.callid.*
 import io.ktor.server.plugins.callloging.*
 import io.ktor.server.request.*
 import io.ktor.server.response.*
 import io.ktor.server.routing.*
 import io.micrometer.core.instrument.MeterRegistry
 import io.micrometer.prometheus.PrometheusMeterRegistry
+import me.snoty.backend.config.Config
 import org.slf4j.event.Level
 
-fun Application.configureMonitoring(meterRegistry: MeterRegistry) {
+fun Application.configureMonitoring(config: Config, meterRegistry: MeterRegistry) {
 	install(MicrometerMetrics) {
 		registry = meterRegistry
 	}
@@ -30,10 +33,12 @@ fun Application.configureMonitoring(meterRegistry: MeterRegistry) {
 		generate(10)
 	}
 	if (meterRegistry is PrometheusMeterRegistry) {
-		routing {
-			get("/metrics") {
-				call.respond(meterRegistry.scrape())
+		embeddedServer(Netty, port = config.prometheusPort.toInt()) {
+			routing {
+				get("/metrics") {
+					call.respond(meterRegistry.scrape())
+				}
 			}
-		}
+		}.start(wait = false)
 	}
 }