Merge pull request #452 from NDLANO/prometheus-metrics

Add prometheus metrics endpoint to applications
NDLANO · Apr 16, 2024 · c9a13a4 · c9a13a4
2 parents 0277302 + 6e512c7
commit c9a13a4
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Showing 2 changed files with 26 additions and 9 deletions.
diff --git a/network/src/main/scala/no/ndla/network/tapir/Routes.scala b/network/src/main/scala/no/ndla/network/tapir/Routes.scala
@@ -8,11 +8,12 @@
 package no.ndla.network.tapir
 
 import com.sun.net.httpserver.HttpServer
-import io.circe.generic.auto._
+import io.circe.generic.auto.*
+import io.prometheus.metrics.model.registry.PrometheusRegistry
 import no.ndla.common.RequestLogger
 import no.ndla.common.configuration.HasBaseProps
 import no.ndla.network.model.RequestInfo
-import no.ndla.network.tapir.NoNullJsonPrinter._
+import no.ndla.network.tapir.NoNullJsonPrinter.*
 import org.log4s.{Logger, getLogger}
 import sttp.model.StatusCode
 import sttp.monad.MonadError
@@ -24,6 +25,8 @@ import sttp.tapir.server.interceptor.exception.{ExceptionContext, ExceptionHandl
 import sttp.tapir.server.interceptor.reject.{RejectContext, RejectHandler}
 import sttp.tapir.server.interceptor.{RequestInterceptor, RequestResult}
 import sttp.tapir.server.jdkhttp.{Id, JdkHttpServer, JdkHttpServerOptions}
+import sttp.tapir.server.metrics.MetricLabels
+import sttp.tapir.server.metrics.prometheus.PrometheusMetrics
 import sttp.tapir.server.model.ValuedEndpointOutput
 import sttp.tapir.{AttributeKey, EndpointInput, statusCode}
 
@@ -85,7 +88,12 @@ trait Routes[F[_]] {
     }
 
     object JDKMiddleware {
-      private def shouldLogRequest(req: ServerRequest): Boolean = s"/${req.uri.path.mkString("/")}" != "/health"
+      private def shouldLogRequest(req: ServerRequest): Boolean = {
+        if (req.uri.path.size != 1) return true
+        if (req.uri.path.head == "metrics") return false
+        if (req.uri.path.head == "health") return false
+        true
+      }
 
       val beforeTime = new AttributeKey[Long]("beforeTime")
       def before(req: ServerRequest): ServerRequest = {
@@ -135,6 +143,12 @@ trait Routes[F[_]] {
     }
 
     def startJdkServerAsync(name: String, port: Int)(warmupFunc: => Unit): HttpServer = {
+      val registry = new PrometheusRegistry()
+      val prometheusMetrics = PrometheusMetrics.default[Id](
+        namespace = "tapir",
+        registry = registry,
+        labels = MetricLabels.Default
+      )
       // val executor: ExecutorService = Executors.newVirtualThreadPerTaskExecutor()
       val executor: ExecutorService = Executors.newWorkStealingPool(props.TAPIR_THREADS)
 
@@ -144,6 +158,7 @@ trait Routes[F[_]] {
         .exceptionHandler(NdlaExceptionHandler[Id]())
         .decodeFailureHandler(decodeFailureHandler[Id])
         .serverLog(None)
+        .metricsInterceptor(prometheusMetrics.metricsInterceptor())
         .prependInterceptor(RequestInterceptor.transformServerRequest[Id](JDKMiddleware.before))
         .prependInterceptor(RequestInterceptor.transformResultEffect(new JDKMiddleware.after))
         .options
@@ -154,6 +169,7 @@ trait Routes[F[_]] {
         .options(options)
         .executor(executor)
         .addEndpoints(endpoints)
+        .addEndpoint(prometheusMetrics.metricsEndpoint)
         .port(port)
         .start()
 

diff --git a/project/Dependencies.scala b/project/Dependencies.scala
@@ -93,12 +93,13 @@ object Dependencies {
     )
 
     lazy val tapir: Seq[ModuleID] = Seq(
-      "com.softwaremill.sttp.tapir"   %% "tapir-http4s-server"     % TapirV,
-      "com.softwaremill.sttp.tapir"   %% "tapir-swagger-ui-bundle" % TapirV,
-      "com.softwaremill.sttp.tapir"   %% "tapir-json-circe"        % TapirV,
-      "com.softwaremill.sttp.tapir"   %% "tapir-jdkhttp-server"    % TapirV,
-      "com.softwaremill.sttp.apispec" %% "openapi-circe-yaml"      % ApiSpecV,
-      "com.softwaremill.sttp.tapir"   %% "tapir-testing"           % TapirV % "test"
+      "com.softwaremill.sttp.tapir"   %% "tapir-http4s-server"      % TapirV,
+      "com.softwaremill.sttp.tapir"   %% "tapir-swagger-ui-bundle"  % TapirV,
+      "com.softwaremill.sttp.tapir"   %% "tapir-json-circe"         % TapirV,
+      "com.softwaremill.sttp.tapir"   %% "tapir-jdkhttp-server"     % TapirV,
+      "com.softwaremill.sttp.tapir"   %% "tapir-prometheus-metrics" % TapirV,
+      "com.softwaremill.sttp.apispec" %% "openapi-circe-yaml"       % ApiSpecV,
+      "com.softwaremill.sttp.tapir"   %% "tapir-testing"            % TapirV % "test"
     ).map {
       // NOTE: tapir-jdkhttp-server includes some logback provider for slf4j
       //       this conflicts with the existing provider, so lets exclude it.