Vertx HTTP: execute custom logic when HTTP server is started

- resolves quarkusio#42366

docs/src/main/asciidoc/http-reference.adoc

@@ -498,6 +498,27 @@ public class MyCustomizer implements HttpServerOptionsCustomizer {
 <1> By making the class a managed bean, Quarkus will take the customizer into account when it starts the Vert.x servers
 <2> In this case, we only care about customizing the HTTP server, so we just override the `customizeHttpServer` method, but users should be aware that `HttpServerOptionsCustomizer` allows configuring the HTTPS and Domain Socket servers as well
 
+
+== How to execute logic when HTTP server started
+
+In order to execute some custom action when the HTTP server is started you'll need to declare an _asynchronous_ CDI observer method. 
+Quarkus _asynchronously_ fires CDI events of types `io.quarkus.vertx.http.HttpServerStart`, `io.quarkus.vertx.http.HttpsServerStart` and `io.quarkus.vertx.http.DomainSocketServerStart` when the corresponding HTTP server starts listening on the configured host and port.
+
+.`HttpServerStart` example
+[source,java]
+----
+@ApplicationScoped
+public class MyListener {
+
+   void httpStarted(@ObservesAsync HttpServerStart start) { <1>
+      // ...notified when the HTTP server starts listening
+   }
+}
+----
+<1> An asynchronous `HttpServerStart` observer method may be declared by annotating an `HttpServerStart` parameter with `@jakarta.enterprise.event.ObservesAsync`.
+
+NOTE: It's not possible to use the `StartupEvent` for this particular use case because this CDI event is fired before the HTTP server is started.
+
 [[reverse-proxy]]
 == Running behind a reverse proxy
 

extensions/vertx-http/deployment/src/test/java/io/quarkus/vertx/http/start/HttpServerStartEventsTest.java

@@ -0,0 +1,69 @@
+package io.quarkus.vertx.http.start;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.File;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import jakarta.annotation.PreDestroy;
+import jakarta.enterprise.context.Dependent;
+import jakarta.enterprise.event.ObservesAsync;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+import io.quarkus.vertx.http.HttpServerStart;
+import io.quarkus.vertx.http.HttpsServerStart;
+import io.smallrye.certs.Format;
+import io.smallrye.certs.junit5.Certificate;
+import io.smallrye.certs.junit5.Certificates;
+
+@Certificates(baseDir = "target/certs", certificates = @Certificate(name = "ssl-test", password = "secret", formats = {
+        Format.JKS, Format.PKCS12, Format.PEM }))
+public class HttpServerStartEventsTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .withApplicationRoot(root -> root.addClasses(MyListener.class)
+                    .addAsResource(new File("target/certs/ssl-test-keystore.jks"), "server-keystore.jks"))
+            .overrideConfigKey("quarkus.http.ssl.certificate.key-store-file", "server-keystore.jks")
+            .overrideConfigKey("quarkus.http.ssl.certificate.key-store-password", "secret");
+
+    @Test
+    public void test() throws InterruptedException {
+        assertTrue(MyListener.HTTP.await(5, TimeUnit.SECONDS));
+        assertTrue(MyListener.HTTPS.await(5, TimeUnit.SECONDS));
+        // httpsStarted() is static
+        assertEquals(1, MyListener.COUNTER.get());
+    }
+
+    @Dependent
+    public static class MyListener {
+
+        static final AtomicInteger COUNTER = new AtomicInteger();
+        static final CountDownLatch HTTP = new CountDownLatch(1);
+        static final CountDownLatch HTTPS = new CountDownLatch(1);
+
+        void httpStarted(@ObservesAsync HttpServerStart start) {
+            assertNotNull(start.options());
+            HTTP.countDown();
+        }
+
+        static void httpsStarted(@ObservesAsync HttpsServerStart start) {
+            assertNotNull(start.options());
+            HTTPS.countDown();
+        }
+
+        @PreDestroy
+        void destroy() {
+            COUNTER.incrementAndGet();
+        }
+
+    }
+
+}

extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/DomainSocketServerStart.java

@@ -0,0 +1,21 @@
+package io.quarkus.vertx.http;
+
+import io.vertx.core.http.HttpServerOptions;
+
+/**
+ * Quarkus fires a CDI event of this type asynchronously when the domain socket server starts listening
+ * on the configured host and port.
+ *
+ * <pre>
+ * &#064;ApplicationScoped
+ * public class MyListener {
+ *
+ *     void domainSocketStarted(&#064;ObservesAsync DomainSocketServerStart start) {
+ *         // ...notified when the domain socket server starts listening
+ *     }
+ * }
+ * </pre>
+ */
+public record DomainSocketServerStart(HttpServerOptions options) {
+
+}

extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/HttpServerStart.java

@@ -0,0 +1,21 @@
+package io.quarkus.vertx.http;
+
+import io.vertx.core.http.HttpServerOptions;
+
+/**
+ * Quarkus fires a CDI event of this type asynchronously when the HTTP server starts listening
+ * on the configured host and port.
+ *
+ * <pre>
+ * &#064;ApplicationScoped
+ * public class MyListener {
+ *
+ *     void httpStarted(&#064;ObservesAsync HttpServerStart start) {
+ *         // ...notified when the HTTP server starts listening
+ *     }
+ * }
+ * </pre>
+ */
+public record HttpServerStart(HttpServerOptions options) {
+
+}

extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/HttpsServerStart.java

@@ -0,0 +1,21 @@
+package io.quarkus.vertx.http;
+
+import io.vertx.core.http.HttpServerOptions;
+
+/**
+ * Quarkus fires a CDI event of this type asynchronously when the HTTPS server starts listening
+ * on the configured host and port.
+ *
+ * <pre>
+ * &#064;ApplicationScoped
+ * public class MyListener {
+ *
+ *     void httpsStarted(&#064;ObservesAsync HttpsServerStart start) {
+ *         // ...notified when the HTTPS server starts listening
+ *     }
+ * }
+ * </pre>
+ */
+public record HttpsServerStart(HttpServerOptions options) {
+
+}

extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/VertxHttpRecorder.java

@@ -23,6 +23,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
@@ -46,6 +47,7 @@
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.quarkus.arc.Arc;
+import io.quarkus.arc.ArcContainer;
 import io.quarkus.arc.InstanceHandle;
 import io.quarkus.arc.runtime.BeanContainer;
 import io.quarkus.bootstrap.runner.Timing;
@@ -71,7 +73,10 @@
 import io.quarkus.tls.runtime.config.TlsConfig;
 import io.quarkus.vertx.core.runtime.VertxCoreRecorder;
 import io.quarkus.vertx.core.runtime.config.VertxConfiguration;
+import io.quarkus.vertx.http.DomainSocketServerStart;
 import io.quarkus.vertx.http.HttpServerOptionsCustomizer;
+import io.quarkus.vertx.http.HttpServerStart;
+import io.quarkus.vertx.http.HttpsServerStart;
 import io.quarkus.vertx.http.ManagementInterface;
 import io.quarkus.vertx.http.runtime.HttpConfiguration.InsecureRequests;
 import io.quarkus.vertx.http.runtime.devmode.RemoteSyncHandler;
@@ -744,8 +749,9 @@ private static CompletableFuture<String> initializeMainHttpServer(Vertx vertx, H
                 launchMode, websocketSubProtocols, registry);
 
         // Customize
-        if (Arc.container() != null) {
-            List<InstanceHandle<HttpServerOptionsCustomizer>> instances = Arc.container()
+        ArcContainer container = Arc.container();
+        if (container != null) {
+            List<InstanceHandle<HttpServerOptionsCustomizer>> instances = container
                     .listAll(HttpServerOptionsCustomizer.class);
             for (InstanceHandle<HttpServerOptionsCustomizer> instance : instances) {
                 HttpServerOptionsCustomizer customizer = instance.get();
@@ -784,12 +790,17 @@ private static CompletableFuture<String> initializeMainHttpServer(Vertx vertx, H
         CompletableFuture<String> futureResult = new CompletableFuture<>();
 
         AtomicInteger connectionCount = new AtomicInteger();
+
+        // Note that a new HttpServer is created for each IO thread but we only want to fire the events (HttpServerStart etc.) once,
+        // for the first server that started listening
+        // See https://vertx.io/docs/vertx-core/java/#_server_sharing for more information
+        AtomicBoolean startEventsFired = new AtomicBoolean();
+
         vertx.deployVerticle(new Supplier<Verticle>() {
             @Override
             public Verticle get() {
                 return new WebDeploymentVerticle(httpMainServerOptions, httpMainSslServerOptions, httpMainDomainSocketOptions,
-                        launchMode,
-                        insecureRequestStrategy, httpConfiguration, connectionCount, registry);
+                        launchMode, insecureRequestStrategy, httpConfiguration, connectionCount, registry, startEventsFired);
             }
         }, new DeploymentOptions().setInstances(ioThreads), new Handler<AsyncResult<String>>() {
             @Override
@@ -1129,11 +1140,12 @@ private static class WebDeploymentVerticle extends AbstractVerticle implements R
         private final HttpConfiguration quarkusConfig;
         private final AtomicInteger connectionCount;
         private final List<Long> reloadingTasks = new CopyOnWriteArrayList<>();
+        private final AtomicBoolean startEventsFired;
 
         public WebDeploymentVerticle(HttpServerOptions httpOptions, HttpServerOptions httpsOptions,
                 HttpServerOptions domainSocketOptions, LaunchMode launchMode,
                 InsecureRequests insecureRequests, HttpConfiguration quarkusConfig, AtomicInteger connectionCount,
-                TlsConfigurationRegistry registry) {
+                TlsConfigurationRegistry registry, AtomicBoolean startEventsFired) {
             this.httpOptions = httpOptions;
             this.httpsOptions = httpsOptions;
             this.launchMode = launchMode;
@@ -1142,6 +1154,7 @@ public WebDeploymentVerticle(HttpServerOptions httpOptions, HttpServerOptions ht
             this.quarkusConfig = quarkusConfig;
             this.connectionCount = connectionCount;
             this.registry = registry;
+            this.startEventsFired = startEventsFired;
             org.crac.Core.getGlobalContext().register(this);
         }
 
@@ -1166,6 +1179,9 @@ public void start(Promise<Void> startFuture) {
                         .fail(new IllegalArgumentException("Must configure at least one of http, https or unix domain socket"));
             }
 
+            ArcContainer container = Arc.container();
+            boolean notifyStartObservers = container != null ? startEventsFired.compareAndSet(false, true) : false;
+
             if (httpServerEnabled) {
                 httpServer = vertx.createHttpServer(httpOptions);
                 if (insecureRequests == HttpConfiguration.InsecureRequests.ENABLED) {
@@ -1196,27 +1212,34 @@ public void handle(HttpServerRequest req) {
                         }
                     });
                 }
-                setupTcpHttpServer(httpServer, httpOptions, false, startFuture, remainingCount, connectionCount);
+                setupTcpHttpServer(httpServer, httpOptions, false, startFuture, remainingCount, connectionCount,
+                        container, notifyStartObservers);
             }
 
             if (domainSocketOptions != null) {
                 domainSocketServer = vertx.createHttpServer(domainSocketOptions);
                 domainSocketServer.requestHandler(ACTUAL_ROOT);
-                setupUnixDomainSocketHttpServer(domainSocketServer, domainSocketOptions, startFuture, remainingCount);
+                setupUnixDomainSocketHttpServer(domainSocketServer, domainSocketOptions, startFuture, remainingCount,
+                        container, notifyStartObservers);
             }
 
             if (httpsOptions != null) {
                 httpsServer = vertx.createHttpServer(httpsOptions);
                 httpsServer.requestHandler(ACTUAL_ROOT);
-                setupTcpHttpServer(httpsServer, httpsOptions, true, startFuture, remainingCount, connectionCount);
+                setupTcpHttpServer(httpsServer, httpsOptions, true, startFuture, remainingCount, connectionCount,
+                        container, notifyStartObservers);
             }
         }
 
         private void setupUnixDomainSocketHttpServer(HttpServer httpServer, HttpServerOptions options,
                 Promise<Void> startFuture,
-                AtomicInteger remainingCount) {
+                AtomicInteger remainingCount, ArcContainer container, boolean notifyStartObservers) {
             httpServer.listen(SocketAddress.domainSocketAddress(options.getHost()), event -> {
                 if (event.succeeded()) {
+                    if (notifyStartObservers) {
+                        container.beanManager().getEvent().select(DomainSocketServerStart.class)
+                                .fireAsync(new DomainSocketServerStart(options));
+                    }
                     if (remainingCount.decrementAndGet() == 0) {
                         startFuture.complete(null);
                     }
@@ -1240,7 +1263,8 @@ private void setupUnixDomainSocketHttpServer(HttpServer httpServer, HttpServerOp
         }
 
         private void setupTcpHttpServer(HttpServer httpServer, HttpServerOptions options, boolean https,
-                Promise<Void> startFuture, AtomicInteger remainingCount, AtomicInteger currentConnectionCount) {
+                Promise<Void> startFuture, AtomicInteger remainingCount, AtomicInteger currentConnectionCount,
+                ArcContainer container, boolean notifyStartObservers) {
 
             if (quarkusConfig.limits.maxConnections.isPresent() && quarkusConfig.limits.maxConnections.getAsInt() > 0) {
                 var tracker = vertx.isMetricsEnabled()
@@ -1315,11 +1339,20 @@ public void handle(AsyncResult<HttpServer> event) {
                         }
 
                         if (https) {
-                            CDI.current().select(HttpCertificateUpdateEventListener.class).get()
+                            container.instance(HttpCertificateUpdateEventListener.class).get()
                                     .register(event.result(), quarkusConfig.tlsConfigurationName.orElse(TlsConfig.DEFAULT_NAME),
                                             "http server");
                         }
 
+                        if (notifyStartObservers) {
+                            Event<Object> startEvent = container.beanManager().getEvent();
+                            if (https) {
+                                startEvent.select(HttpsServerStart.class).fireAsync(new HttpsServerStart(options));
+                            } else {
+                                startEvent.select(HttpServerStart.class).fireAsync(new HttpServerStart(options));
+                            }
+                        }
+
                         if (remainingCount.decrementAndGet() == 0) {
                             //make sure we only complete once
                             startFuture.complete(null);