resolves #1653 export metrics using Prometheus format

yuzutech · Oct 12, 2023 · 15c82fd · 15c82fd
1 parent 759ca1a
commit 15c82fd
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Showing 9 changed files with 72 additions and 45 deletions.
diff --git a/server/pom.xml b/server/pom.xml
@@ -26,6 +26,7 @@
     <structurizr-dsl.version>1.32.0</structurizr-dsl.version>
     <structurizr-export.version>1.16.1</structurizr-export.version>
     <structurizr-core.version>1.26.1</structurizr-core.version>
+    <caffeine.version>3.1.8</caffeine.version>
   </properties>
 
   <dependencies>
@@ -59,7 +60,7 @@
     <dependency>
       <groupId>com.github.ben-manes.caffeine</groupId>
       <artifactId>caffeine</artifactId>
-      <version>3.1.8</version>
+      <version>${caffeine.version}</version>
     </dependency>
     <dependency>
       <groupId>com.googlecode.owasp-java-html-sanitizer</groupId>

diff --git a/server/src/main/java/io/kroki/server/Main.java b/server/src/main/java/io/kroki/server/Main.java
@@ -2,6 +2,7 @@
 
 import io.vertx.config.ConfigRetriever;
 import io.vertx.core.Vertx;
+import io.vertx.core.VertxOptions;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import java.util.Properties;
@@ -27,12 +28,13 @@ public static String getApplicationProperty(String key, String defaultValue) {
 
   public static void main(String[] args) {
     Vertx vertx = Vertx.vertx();
+    VertxOptions vertxOptions = new VertxOptions();
     ConfigRetriever retriever = ConfigRetriever.create(vertx);
     retriever.getConfig(configResult -> {
       if (configResult.failed()) {
         logger.error("Unable to start", configResult.cause());
       } else {
-        Server.start(vertx, configResult.result(), startResult -> {
+        Server.start(vertx, vertxOptions, configResult.result(), startResult -> {
           if (startResult.failed()) {
             logger.error("Unable to start", startResult.cause());
           }

diff --git a/server/src/main/java/io/kroki/server/Server.java b/server/src/main/java/io/kroki/server/Server.java
@@ -4,34 +4,7 @@
 import io.kroki.server.error.ErrorHandler;
 import io.kroki.server.error.InvalidRequestHandler;
 import io.kroki.server.log.Logging;
-import io.kroki.server.service.Blockdiag;
-import io.kroki.server.service.Bpmn;
-import io.kroki.server.service.Bytefield;
-import io.kroki.server.service.D2;
-import io.kroki.server.service.KrokiBlockedThreadChecker;
-import io.kroki.server.service.TikZ;
-import io.kroki.server.service.Dbml;
-import io.kroki.server.service.DiagramRegistry;
-import io.kroki.server.service.DiagramRest;
-import io.kroki.server.service.Diagramsnet;
-import io.kroki.server.service.Ditaa;
-import io.kroki.server.service.Erd;
-import io.kroki.server.service.Excalidraw;
-import io.kroki.server.service.Graphviz;
-import io.kroki.server.service.HealthHandler;
-import io.kroki.server.service.HelloHandler;
-import io.kroki.server.service.Mermaid;
-import io.kroki.server.service.Nomnoml;
-import io.kroki.server.service.Pikchr;
-import io.kroki.server.service.Plantuml;
-import io.kroki.server.service.ServiceVersion;
-import io.kroki.server.service.Structurizr;
-import io.kroki.server.service.Svgbob;
-import io.kroki.server.service.Symbolator;
-import io.kroki.server.service.Umlet;
-import io.kroki.server.service.Vega;
-import io.kroki.server.service.Wavedrom;
-import io.kroki.server.service.Wireviz;
+import io.kroki.server.service.*;
 import io.vertx.config.ConfigRetriever;
 import io.vertx.core.AbstractVerticle;
 import io.vertx.core.AsyncResult;
@@ -67,11 +40,12 @@ public class Server extends AbstractVerticle {
   @Override
   public void start(Promise<Void> startPromise) {
     ConfigRetriever retriever = ConfigRetriever.create(vertx);
+    VertxOptions vertxOptions = new VertxOptions();
     retriever.getConfig(configResult -> {
       if (configResult.failed()) {
         startPromise.fail(configResult.cause());
       } else {
-        start(vertx, configResult.result(), startResult -> {
+        start(vertx, vertxOptions, configResult.result(), startResult -> {
           if (startResult.succeeded()) {
             startPromise.complete();
           } else {
@@ -82,7 +56,7 @@ public void start(Promise<Void> startPromise) {
     });
   }
 
-  static void start(Vertx vertx, JsonObject config, Handler<AsyncResult<HttpServer>> listenHandler) {
+  static void start(Vertx vertx, VertxOptions vertxOptions, JsonObject config, Handler<AsyncResult<HttpServer>> listenHandler) {
     HttpServerOptions serverOptions = new HttpServerOptions();
     Optional<Integer> maxUriLength = Optional.ofNullable(config.getInteger("KROKI_MAX_URI_LENGTH"));
     maxUriLength.ifPresent(serverOptions::setMaxInitialLineLength);
@@ -151,8 +125,13 @@ static void start(Vertx vertx, JsonObject config, Handler<AsyncResult<HttpServer
       .handler(bodyHandler)
       .handler(new DiagramRest(registry).create());
 
+    // metrics
+    final var blockedThreadChecker = new KrokiBlockedThreadChecker(vertx, vertxOptions);
+    MetricHandler metricHandler = new MetricHandler(blockedThreadChecker);
+    Handler<RoutingContext> metricHandlerService = metricHandler.create();
+    router.get("/metrics")
+      .handler(metricHandlerService);
     // health
-    final var blockedThreadChecker = new KrokiBlockedThreadChecker(vertx, new VertxOptions());//TODO this should match the option used to init vertx
     HealthHandler healthHandler = new HealthHandler(registry.getVersions(), blockedThreadChecker);
     Handler<RoutingContext> healthHandlerService = healthHandler.create();
     router.get("/health")

diff --git a/server/src/main/java/io/kroki/server/service/DiagramHandler.java b/server/src/main/java/io/kroki/server/service/DiagramHandler.java
@@ -83,7 +83,7 @@ public Handler<RoutingContext> createPost(String serviceName) {
         JsonObject jsonBody;
         MIMEHeader contentType = routingContext.parsedHeaders().contentType();
         if (contentType != null && contentType.value() != null && contentType.value().equals("application/json")) {
-          String bodyAsString = routingContext.getBodyAsString();
+          String bodyAsString = routingContext.body().asString();
           if (bodyAsString == null || bodyAsString.trim().isEmpty()) {
             routingContext.fail(new BadRequestException("Request body must not be empty."));
             return;
@@ -98,7 +98,7 @@ public Handler<RoutingContext> createPost(String serviceName) {
         } else {
           // assumes that the Content-Type is "plain/text" (default)
           jsonBody = new JsonObject();
-          diagramSource = routingContext.getBodyAsString();
+          diagramSource = routingContext.body().asString();
           if (diagramSource == null || diagramSource.trim().isEmpty()) {
             routingContext.fail(new BadRequestException("Request body must not be empty."));
             return;

diff --git a/server/src/main/java/io/kroki/server/service/DiagramRest.java b/server/src/main/java/io/kroki/server/service/DiagramRest.java
@@ -20,7 +20,7 @@ public DiagramRest(DiagramRegistry registry) {
 
   public Handler<RoutingContext> create() {
     return routingContext -> {
-      String bodyAsString = routingContext.getBodyAsString();
+      String bodyAsString = routingContext.body().asString();
       if (bodyAsString == null || bodyAsString.trim().isEmpty()) {
         routingContext.fail(new BadRequestException("Request body must not be empty."));
         return;

diff --git a/server/src/main/java/io/kroki/server/service/HealthHandler.java b/server/src/main/java/io/kroki/server/service/HealthHandler.java
@@ -17,8 +17,6 @@ public class HealthHandler {
   private final String krokiBuildHash;
   private final List<ServiceVersion> serviceVersions;
 
-  private final KrokiBlockedThreadChecker blockedThreadChecker;
-
   public HealthHandler(Map<String, String> versions) {
     this(versions, null);
   }
@@ -31,7 +29,6 @@ public HealthHandler(Map<String, String> versions, KrokiBlockedThreadChecker blo
     for (Map.Entry<String, String> entry : versions.entrySet()) {
       serviceVersions.add(new ServiceVersion(entry.getKey(), entry.getValue()));
     }
-    this.blockedThreadChecker = blockedThreadChecker;
   }
 
   public Handler<RoutingContext> create() {
@@ -47,10 +44,6 @@ public Handler<RoutingContext> create() {
       for (ServiceVersion serviceVersion : serviceVersions) {
         versions.put(serviceVersion.getService(), serviceVersion.getVersion());
       }
-      if (blockedThreadChecker != null) {
-        data.put("blockedWorkerPercentage", blockedThreadChecker.blockedWorkerThreadPercentage());
-        data.put("blockedEventLoopPercentage", blockedThreadChecker.blockedEventLoopThreadPercentage());
-      }
       routingContext
         .response()
         .putHeader(HttpHeaders.CONTENT_TYPE, "application/health+json")

diff --git a/server/src/main/java/io/kroki/server/service/MetricHandler.java b/server/src/main/java/io/kroki/server/service/MetricHandler.java
@@ -0,0 +1,36 @@
+package io.kroki.server.service;
+
+import io.vertx.core.Handler;
+import io.vertx.core.buffer.Buffer;
+import io.vertx.core.http.HttpHeaders;
+import io.vertx.ext.web.RoutingContext;
+
+public class MetricHandler {
+
+  private final KrokiBlockedThreadChecker blockedThreadChecker;
+  private final String namespace;
+
+  public MetricHandler(KrokiBlockedThreadChecker blockedThreadChecker) {
+    this.blockedThreadChecker = blockedThreadChecker;
+    this.namespace = "kroki";
+  }
+
+  public Handler<RoutingContext> create() {
+    String workerThreadBlockedMetricName = namespace + "_worker_thread_blocked_percentage";
+    String eventLoopThreadBlockedMetricName = namespace + "_event_loop_thread_blocked_percentage";
+    return routingContext -> {
+      long timestamp = System.currentTimeMillis();
+      Buffer buffer = Buffer.buffer();
+      buffer.appendString("# HELP " + workerThreadBlockedMetricName + " The percentage of worker thread blocked.\n");
+      buffer.appendString("# TYPE " + workerThreadBlockedMetricName + " gauge\n");
+      buffer.appendString(String.join(" ", workerThreadBlockedMetricName, Long.toString(blockedThreadChecker.blockedWorkerThreadPercentage()), Long.toString(timestamp)) + "\n\n");
+      buffer.appendString("# HELP " + eventLoopThreadBlockedMetricName + " The percentage of event loop thread blocked.\n");
+      buffer.appendString("# TYPE " + eventLoopThreadBlockedMetricName + " gauge\n");
+      buffer.appendString(String.join(" ", eventLoopThreadBlockedMetricName, Long.toString(blockedThreadChecker.blockedEventLoopThreadPercentage()), Long.toString(timestamp)) + "\n\n");
+      routingContext
+        .response()
+        .putHeader(HttpHeaders.CONTENT_TYPE, "text/plain; version=0.0.4")
+        .end(buffer);
+    };
+  }
+}
diff --git a/server/src/main/java/io/kroki/server/service/Structurizr.java b/server/src/main/java/io/kroki/server/service/Structurizr.java
@@ -236,6 +236,7 @@ public StructurizrTheme(JsonObject object) {
     if (elementsObject instanceof JsonArray) {
       for (Object elementObject : ((JsonArray) elementsObject).getList()) {
         if (elementObject instanceof Map) {
+          @SuppressWarnings("unchecked")
           JsonObject element = new JsonObject((Map<String, Object>) elementObject);
           ElementStyle elementStyle = new ElementStyle(
             element.getString("tag"),
@@ -263,9 +264,8 @@ public List<ElementStyle> getElementStyles() {
   }
 
   public List<RelationshipStyle> getRelationshipStyle() {
-    List<RelationshipStyle> result = new ArrayList<>();
     // remind: RelationshipStyle does not have a public constructor, as a result, we cannot instantiate it.
-    return result;
+    return new ArrayList<>();
   }
 
   private Shape getShape(JsonObject element) {

diff --git a/server/src/test/java/io/kroki/server/ServerTest.java b/server/src/test/java/io/kroki/server/ServerTest.java
@@ -50,6 +50,22 @@ void http_server_check_response(Vertx vertx, VertxTestContext testContext) {
       })));
   }
 
+  @Test
+  void http_server_check_metrics(Vertx vertx, VertxTestContext testContext) {
+    WebClient client = WebClient.create(vertx);
+    client.get(port, "localhost", "/metrics")
+      .as(BodyCodec.string())
+      .send(testContext.succeeding(response -> testContext.verify(() -> {
+        assertThat(response.body()).contains("# HELP kroki_worker_thread_blocked_percentage");
+        assertThat(response.body()).contains("# TYPE kroki_worker_thread_blocked_percentage gauge");
+        assertThat(response.body()).contains("# HELP kroki_event_loop_thread_blocked_percentage The percentage of event loop thread blocked.");
+        assertThat(response.body()).contains("# TYPE kroki_event_loop_thread_blocked_percentage gauge");
+        assertThat(response.body()).contains("kroki_worker_thread_blocked_percentage 0 ");
+        assertThat(response.body()).contains("kroki_event_loop_thread_blocked_percentage 0 ");
+        testContext.completeNow();
+      })));
+  }
+
   @Test
   void http_server_check_cors_handling_regular_origin(Vertx vertx, VertxTestContext testContext) {
     WebClient client = WebClient.create(vertx);