Fix Class Cast Exception when using OpenTelemetry and max-connections property

extensions/opentelemetry/deployment/src/test/java/io/quarkus/opentelemetry/deployment/metrics/ClassCastExceptionTest.java

@@ -0,0 +1,44 @@
+package io.quarkus.opentelemetry.deployment.metrics;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.opentelemetry.deployment.common.exporter.InMemoryMetricExporter;
+import io.quarkus.opentelemetry.deployment.common.exporter.InMemoryMetricExporterProvider;
+import io.quarkus.opentelemetry.deployment.common.exporter.TestSpanExporter;
+import io.quarkus.opentelemetry.deployment.common.exporter.TestSpanExporterProvider;
+import io.quarkus.test.QuarkusUnitTest;
+
+public class ClassCastExceptionTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest TEST = new QuarkusUnitTest()
+            .setArchiveProducer(
+                    () -> ShrinkWrap.create(JavaArchive.class)
+                            .addClasses(TestSpanExporter.class, TestSpanExporterProvider.class)
+                            .addClasses(InMemoryMetricExporter.class, InMemoryMetricExporterProvider.class)
+                            .addAsResource(new StringAsset(InMemoryMetricExporterProvider.class.getCanonicalName()),
+                                    "META-INF/services/io.opentelemetry.sdk.autoconfigure.spi.metrics.ConfigurableMetricExporterProvider")
+                            .add(new StringAsset(
+                                    "quarkus.otel.metrics.enabled=true\n" +
+                                            "quarkus.otel.metrics.exporter=in-memory\n" +
+                                            "quarkus.otel.metric.export.interval=300ms\n" +
+                                            "quarkus.http.limits.max-connections=50\n" +
+                                            "quarkus.otel.traces.exporter=none\n" +
+                                            "quarkus.otel.logs.exporter=none\n"),
+                                    "application.properties"));
+
+    /**
+     * ClassCastException when using OpenTelemetry and max-connections property
+     * See https://github.com/quarkusio/quarkus/issues/43852
+     */
+    @Test
+    public void testReproducer() {
+        // This test is successful if it does not throw an exception
+        Assertions.assertTrue(true);
+    }
+}

extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/tracing/intrumentation/vertx/OpenTelemetryVertxMetricsFactory.java

@@ -2,6 +2,7 @@
 
 import java.util.Optional;
 
+import io.quarkus.vertx.http.runtime.ExtendedQuarkusVertxHttpMetrics;
 import io.vertx.core.Context;
 import io.vertx.core.VertxOptions;
 import io.vertx.core.http.HttpServerOptions;
@@ -16,7 +17,7 @@
  * This is used to retrieve the route name from Vert.x. This is useful for OpenTelemetry to generate the Span name and
  * <code>http.route</code> attribute. Right now, there is no other way to retrieve the route name from Vert.x using the
  * Telemetry SPI, so we need to rely on the Metrics SPI.
- *
+ * <p>
  * Right now, it is not possible to register multiple <code>VertxMetrics</code>, meaning that only a single one is
  * available per Quarkus instance. To avoid clashing with other extensions that provide Metrics data (like the
  * Micrometer extension), we only register the {@link OpenTelemetryVertxMetricsFactory} if the
@@ -25,17 +26,19 @@
 public class OpenTelemetryVertxMetricsFactory implements VertxMetricsFactory {
     @Override
     public VertxMetrics metrics(final VertxOptions options) {
-        return new VertxMetrics() {
-            @Override
-            public HttpServerMetrics<?, ?, ?> createHttpServerMetrics(final HttpServerOptions options,
-                    final SocketAddress localAddress) {
-                return new OpenTelemetryHttpServerMetrics();
-            }
-        };
+        return new OpenTelemetryHttpServerMetrics();
     }
 
     public static class OpenTelemetryHttpServerMetrics
-            implements HttpServerMetrics<OpenTelemetryHttpServerMetrics.MetricRequest, Object, Object> {
+            implements HttpServerMetrics<OpenTelemetryHttpServerMetrics.MetricRequest, Object, Object>,
+            VertxMetrics, ExtendedQuarkusVertxHttpMetrics {
+
+        @Override
+        public HttpServerMetrics<?, ?, ?> createHttpServerMetrics(final HttpServerOptions options,
+                final SocketAddress localAddress) {
+            return this;
+        }
+
         @Override
         public MetricRequest requestBegin(final Object socketMetric, final HttpRequest request) {
             return MetricRequest.request(request);
@@ -48,6 +51,12 @@ public void requestRouted(final MetricRequest requestMetric, final String route)
             }
         }
 
+        @Override
+        public ConnectionTracker getHttpConnectionTracker() {
+            // To be implemented if we decide to instrument with OpenTelemetry. See VertxMeterBinderAdapter for an example.
+            return ExtendedQuarkusVertxHttpMetrics.NOOP_CONNECTION_TRACKER;
+        }
+
         static final class MetricRequest {
             private final HttpRequest request;