Spring Webflux Library Instrumentation (#7899)

Resolves
#7436

* Created new Module `spring-webflux-5.3` which contains only
server-side library instrumentation
* Minimum supported version is 5.3 because there are various problems in
older versions of reactor and webflux that prevent a few of the tests
from passing.
* Moved existing `spring-webflux-5.0` (webclient instrumentation) into a
common `spring-webflux` folder next to the 5.3 (server) instrumentation.
Moved the README to the parent folder so the docs are cohesive between
client/server instrumentation.
* Implemented `WebFilter` which instruments the server-side 
* Depends on the `reactor-3.1` instrumentation to pass the context
around. Registers the react hook when it creates the `WebFilter`
* Tests using the standard HTTP server test suite

---------

Co-authored-by: Trask Stalnaker <[email protected]>
Co-authored-by: Mateusz Rzeszutek <[email protected]>

Author: 3 people

docs/supported-libraries.md

@@ -21,7 +21,7 @@ dependencies {
   implementation(project(":instrumentation:spring:spring-webmvc:spring-webmvc-5.3:library"))
   implementation(project(":instrumentation:spring:spring-webmvc:spring-webmvc-6.0:library"))
   compileOnly("jakarta.servlet:jakarta.servlet-api:5.0.0")
-  implementation(project(":instrumentation:spring:spring-webflux-5.0:library"))
+  implementation(project(":instrumentation:spring:spring-webflux:spring-webflux-5.3:library"))
   implementation(project(":instrumentation:micrometer:micrometer-1.5:library"))
 
   compileOnly("org.springframework.kafka:spring-kafka:2.9.0")

instrumentation/spring/spring-boot-autoconfigure/README.md

@@ -6,7 +6,7 @@
 package io.opentelemetry.instrumentation.spring.autoconfigure.httpclients.webclient;
 
 import io.opentelemetry.api.OpenTelemetry;
-import io.opentelemetry.instrumentation.spring.webflux.v5_0.client.SpringWebfluxTelemetry;
+import io.opentelemetry.instrumentation.spring.webflux.v5_3.SpringWebfluxTelemetry;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.web.reactive.function.client.WebClient;

instrumentation/spring/spring-boot-autoconfigure/build.gradle.kts

@@ -39,7 +39,7 @@ muzzle {
 }
 
 dependencies {
-  implementation(project(":instrumentation:spring:spring-webflux-5.0:library"))
+  implementation(project(":instrumentation:spring:spring-webflux:spring-webflux-5.3:library"))
 
   compileOnly("org.springframework:spring-webflux:5.0.0.RELEASE")
   compileOnly("io.projectreactor.ipc:reactor-netty:0.7.0.RELEASE")
@@ -51,7 +51,7 @@ 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-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")
   testLibrary("org.springframework.boot:spring-boot-starter-test:2.0.0.RELEASE")

instrumentation/spring/spring-boot-autoconfigure/src/main/java/io/opentelemetry/instrumentation/spring/autoconfigure/httpclients/webclient/WebClientBeanPostProcessor.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.instrumentation.spring.webflux.v5_0.client;
+
+import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
+import io.opentelemetry.instrumentation.api.instrumenter.net.PeerServiceAttributesExtractor;
+import io.opentelemetry.instrumentation.spring.webflux.v5_3.internal.SpringWebfluxTelemetryClientBuilder;
+import io.opentelemetry.instrumentation.spring.webflux.v5_3.internal.WebClientNetAttributesGetter;
+import io.opentelemetry.instrumentation.spring.webflux.v5_3.internal.WebClientTracingFilter;
+import io.opentelemetry.javaagent.bootstrap.internal.CommonConfig;
+import io.opentelemetry.javaagent.bootstrap.internal.InstrumentationConfig;
+import java.util.List;
+import org.springframework.web.reactive.function.client.ClientRequest;
+import org.springframework.web.reactive.function.client.ClientResponse;
+import org.springframework.web.reactive.function.client.ExchangeFilterFunction;
+
+public final class WebClientHelper {
+
+  private static final Instrumenter<ClientRequest, ClientResponse> instrumenter =
+      new SpringWebfluxTelemetryClientBuilder(GlobalOpenTelemetry.get())
+          .setCapturedClientRequestHeaders(CommonConfig.get().getClientRequestHeaders())
+          .setCapturedClientResponseHeaders(CommonConfig.get().getClientResponseHeaders())
+          .addClientAttributesExtractor(
+              PeerServiceAttributesExtractor.create(
+                  new WebClientNetAttributesGetter(), CommonConfig.get().getPeerServiceMapping()))
+          .setCaptureExperimentalSpanAttributes(
+              InstrumentationConfig.get()
+                  .getBoolean(
+                      "otel.instrumentation.spring-webflux.experimental-span-attributes", false))
+          .build();
+
+  public static void addFilter(List<ExchangeFilterFunction> exchangeFilterFunctions) {
+    for (ExchangeFilterFunction filterFunction : exchangeFilterFunctions) {
+      if (filterFunction instanceof WebClientTracingFilter) {
+        return;
+      }
+    }
+    exchangeFilterFunctions.add(
+        new WebClientTracingFilter(instrumenter, GlobalOpenTelemetry.get().getPropagators()));
+  }
+
+  private WebClientHelper() {}
+}