convert spring-webflux groovy test to java (#9677)

Co-authored-by: Jean Bisutti <jean.bisutti@gmail.com>

instrumentation/spring/spring-webflux/spring-webflux-5.0/javaagent/build.gradle.kts

@@ -52,6 +52,8 @@ dependencies {
   testInstrumentation(project(":instrumentation:reactor:reactor-3.1:javaagent"))
   testInstrumentation(project(":instrumentation:reactor:reactor-netty:reactor-netty-1.0:javaagent"))
 
+  testImplementation(project(":instrumentation:spring:spring-webflux:spring-webflux-5.0:testing"))
+
   testImplementation(project(":instrumentation:spring:spring-webflux:spring-webflux-5.3:testing"))
 
   testLibrary("org.springframework.boot:spring-boot-starter-webflux:2.0.0.RELEASE")

instrumentation/spring/spring-webflux/spring-webflux-5.0/javaagent/src/test/java/io/opentelemetry/javaagent/instrumentation/spring/webflux/v5_0/server/SpringThreadedSpringWebfluxTest.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.instrumentation.spring.webflux.v5_0.server;
+
+import io.opentelemetry.instrumentation.spring.webflux.IpcSingleThreadNettyCustomizer;
+import io.opentelemetry.instrumentation.spring.webflux.server.SingleThreadNettyCustomizer;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.boot.web.embedded.netty.NettyReactiveWebServerFactory;
+import org.springframework.boot.web.embedded.netty.NettyServerCustomizer;
+import org.springframework.context.annotation.Bean;
+import server.SpringWebFluxTestApplication;
+
+/**
+ * Run all Webflux tests under netty event loop having only 1 thread. Some of the bugs are better
+ * visible in this setup because same thread is reused for different requests.
+ */
+@SpringBootTest(
+    webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
+    classes = {
+      SpringWebFluxTestApplication.class,
+      SpringThreadedSpringWebfluxTest.ForceSingleThreadedNettyAutoConfiguration.class
+    })
+class SpringThreadedSpringWebfluxTest extends SpringWebfluxTest {
+
+  @TestConfiguration
+  static class ForceSingleThreadedNettyAutoConfiguration {
+    @Bean
+    NettyReactiveWebServerFactory nettyFactory() {
+      NettyReactiveWebServerFactory factory = new NettyReactiveWebServerFactory();
+      factory.addServerCustomizers(customizer());
+      return factory;
+    }
+  }
+
+  static NettyServerCustomizer customizer() {
+    if (Boolean.getBoolean("testLatestDeps")) {
+      return new SingleThreadNettyCustomizer();
+    }
+    return new IpcSingleThreadNettyCustomizer();
+  }
+}

instrumentation/spring/spring-webflux/spring-webflux-5.0/testing/build.gradle.kts

@@ -0,0 +1,11 @@
+plugins {
+  id("otel.java-conventions")
+}
+
+dependencies {
+  implementation(project(":testing-common"))
+
+  compileOnly("org.springframework:spring-webflux:5.0.0.RELEASE")
+  compileOnly("org.springframework.boot:spring-boot-starter-reactor-netty:2.0.0.RELEASE")
+  compileOnly("org.springframework.boot:spring-boot:2.0.0.RELEASE")
+}

instrumentation/spring/spring-webflux/spring-webflux-5.0/testing/src/main/java/io/opentelemetry/instrumentation/spring/webflux/IpcSingleThreadNettyCustomizer.java

@@ -0,0 +1,17 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.spring.webflux;
+
+import org.springframework.boot.web.embedded.netty.NettyServerCustomizer;
+import reactor.ipc.netty.http.server.HttpServerOptions;
+
+public class IpcSingleThreadNettyCustomizer implements NettyServerCustomizer {
+
+  @Override
+  public void customize(HttpServerOptions.Builder builder) {
+    builder.loopResources(reactor.ipc.netty.resources.LoopResources.create("my-http", 1, true));
+  }
+}

instrumentation/spring/spring-webflux/spring-webflux-5.3/testing/build.gradle.kts

@@ -11,4 +11,6 @@ dependencies {
   // latest dep tests.
   compileOnly("io.projectreactor.ipc:reactor-netty:0.7.0.RELEASE")
   compileOnly("io.projectreactor.netty:reactor-netty-http:1.0.7")
+
+  compileOnly("org.springframework.boot:spring-boot:2.1.0.RELEASE")
 }

instrumentation/spring/spring-webflux/spring-webflux-5.3/testing/src/main/java/io/opentelemetry/instrumentation/spring/webflux/server/SingleThreadNettyCustomizer.java

@@ -0,0 +1,17 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.spring.webflux.server;
+
+import org.springframework.boot.web.embedded.netty.NettyServerCustomizer;
+import reactor.netty.http.server.HttpServer;
+
+public class SingleThreadNettyCustomizer implements NettyServerCustomizer {
+
+  @Override
+  public HttpServer apply(HttpServer server) {
+    return server.runOn(reactor.netty.resources.LoopResources.create("my-http", 1, true));
+  }
+}

settings.gradle.kts

@@ -519,6 +519,7 @@ include(":instrumentation:spring:spring-webmvc:spring-webmvc-6.0:library")
 include(":instrumentation:spring:spring-webmvc:spring-webmvc-common:javaagent")
 include(":instrumentation:spring:spring-webmvc:spring-webmvc-common:testing")
 include(":instrumentation:spring:spring-webflux:spring-webflux-5.0:javaagent")
+include(":instrumentation:spring:spring-webflux:spring-webflux-5.0:testing")
 include(":instrumentation:spring:spring-webflux:spring-webflux-5.3:testing")
 include(":instrumentation:spring:spring-webflux:spring-webflux-5.3:library")
 include(":instrumentation:spring:spring-ws-2.0:javaagent")