Migrate Spring Web{flux} instrumentation to Decorator

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/decorator/BaseDecorator.java

@@ -122,19 +122,27 @@ public abstract class BaseDecorator {
    * @return
    */
   public String spanNameForMethod(final Method method) {
-    final Class<?> declaringClass = method.getDeclaringClass();
+    return spanNameForClass(method.getDeclaringClass()) + "." + method.getName();
-    String className;
+  }
-    if (declaringClass.isAnonymousClass()) {
+
-      className = declaringClass.getName();
+  /**
-      if (declaringClass.getPackage() != null) {
+   * This method is used to generate an acceptable span (operation) name based on a given class
-        final String pkgName = declaringClass.getPackage().getName();
+   * reference. Anonymous classes are named based on their parent.
-        if (!pkgName.isEmpty()) {
+   *
-          className = declaringClass.getName().replace(pkgName, "").substring(1);
+   * @param clazz
-        }
+   * @return
-      }
+   */
-    } else {
+  public String spanNameForClass(final Class clazz) {
-      className = declaringClass.getSimpleName();
+    if (!clazz.isAnonymousClass()) {
+      return clazz.getSimpleName();
     }
-    return className + "." + method.getName();
+    String className = clazz.getName();
+    if (clazz.getPackage() != null) {
+      final String pkgName = clazz.getPackage().getName();
+      if (!pkgName.isEmpty()) {
+        className = clazz.getName().replace(pkgName, "").substring(1);
+      }
+    }
+    return className;
   }
 }

dd-java-agent/instrumentation/spring-web/src/main/java/datadog/trace/instrumentation/springweb/DispatcherServletInstrumentation.java

@@ -1,6 +1,7 @@
 package datadog.trace.instrumentation.springweb;
 
-import static io.opentracing.log.Fields.ERROR_OBJECT;
+import static datadog.trace.instrumentation.springweb.SpringWebHttpServerDecorator.DECORATE;
+import static datadog.trace.instrumentation.springweb.SpringWebHttpServerDecorator.DECORATE_RENDER;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.isProtected;
 import static net.bytebuddy.matcher.ElementMatchers.nameStartsWith;
@@ -11,10 +12,8 @@ import com.google.auto.service.AutoService;
 import datadog.trace.agent.tooling.Instrumenter;
 import io.opentracing.Scope;
 import io.opentracing.Span;
-import io.opentracing.Tracer;
 import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import net.bytebuddy.asm.Advice;
@@ -35,6 +34,17 @@ public final class DispatcherServletInstrumentation extends Instrumenter.Default
     return named("org.springframework.web.servlet.DispatcherServlet");
   }
 
+  @Override
+  public String[] helperClassNames() {
+    return new String[] {
+      "datadog.trace.agent.decorator.BaseDecorator",
+      "datadog.trace.agent.decorator.ServerDecorator",
+      "datadog.trace.agent.decorator.HttpServerDecorator",
+      packageName + ".SpringWebHttpServerDecorator",
+      packageName + ".SpringWebHttpServerDecorator$1",
+    };
+  }
+
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
     final Map<ElementMatcher<? super MethodDescription>, String> transformers = new HashMap<>();
@@ -57,29 +67,17 @@ public final class DispatcherServletInstrumentation extends Instrumenter.Default
 
     @Advice.OnMethodEnter(suppress = Throwable.class)
     public static Scope startSpan(@Advice.Argument(0) final ModelAndView mv) {
-
+      final Scope scope = GlobalTracer.get().buildSpan("response.render").startActive(true);
-      final Tracer.SpanBuilder builder =
+      DECORATE_RENDER.afterStart(scope);
-          GlobalTracer.get()
+      DECORATE_RENDER.onRender(scope, mv);
-              .buildSpan("response.render")
+      return scope;
-              .withTag(Tags.COMPONENT.getKey(), "spring-webmvc");
-      if (mv.getViewName() != null) {
-        builder.withTag("view.name", mv.getViewName());
-      }
-      if (mv.getView() != null) {
-        builder.withTag("view.type", mv.getView().getClass().getName());
-      }
-      return builder.startActive(true);
     }
 
     @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
     public static void stopSpan(
         @Advice.Enter final Scope scope, @Advice.Thrown final Throwable throwable) {
-
+      DECORATE_RENDER.onError(scope, throwable);
-      if (throwable != null) {
+      DECORATE_RENDER.beforeFinish(scope);
-        final Span span = scope.span();
-        Tags.ERROR.set(span, true);
-        span.log(Collections.singletonMap(ERROR_OBJECT, throwable));
-      }
       scope.close();
     }
   }
@@ -90,7 +88,7 @@ public final class DispatcherServletInstrumentation extends Instrumenter.Default
       final Scope scope = GlobalTracer.get().scopeManager().active();
       if (scope != null && exception != null) {
         final Span span = scope.span();
-        span.log(Collections.singletonMap(ERROR_OBJECT, exception));
+        DECORATE.onError(span, exception);
         // We want to capture the stacktrace, but that doesn't mean it should be an error.
         // We rely on a decorator to set the error state based on response code. (5xx -> error)
         Tags.ERROR.set(span, false);

dd-java-agent/instrumentation/spring-web/src/main/java/datadog/trace/instrumentation/springweb/HandlerAdapterInstrumentation.java

@@ -1,7 +1,7 @@
 package datadog.trace.instrumentation.springweb;
 
 import static datadog.trace.agent.tooling.ByteBuddyElementMatchers.safeHasSuperType;
-import static io.opentracing.log.Fields.ERROR_OBJECT;
+import static datadog.trace.instrumentation.springweb.SpringWebHttpServerDecorator.DECORATE;
 import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isInterface;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
@@ -14,11 +14,7 @@ import static net.bytebuddy.matcher.ElementMatchers.takesArguments;
 
 import com.google.auto.service.AutoService;
 import datadog.trace.agent.tooling.Instrumenter;
-import datadog.trace.api.DDSpanTypes;
-import datadog.trace.api.DDTags;
 import io.opentracing.Scope;
-import io.opentracing.Span;
-import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
 import java.lang.reflect.Method;
 import java.util.Map;
@@ -30,7 +26,6 @@ import net.bytebuddy.description.type.TypeDescription;
 import net.bytebuddy.matcher.ElementMatcher;
 import org.springframework.web.HttpRequestHandler;
 import org.springframework.web.method.HandlerMethod;
-import org.springframework.web.servlet.HandlerMapping;
 import org.springframework.web.servlet.mvc.Controller;
 
 @AutoService(Instrumenter.class)
@@ -46,6 +41,17 @@ public final class HandlerAdapterInstrumentation extends Instrumenter.Default {
         .and(safeHasSuperType(named("org.springframework.web.servlet.HandlerAdapter")));
   }
 
+  @Override
+  public String[] helperClassNames() {
+    return new String[] {
+      "datadog.trace.agent.decorator.BaseDecorator",
+      "datadog.trace.agent.decorator.ServerDecorator",
+      "datadog.trace.agent.decorator.HttpServerDecorator",
+      packageName + ".SpringWebHttpServerDecorator",
+      packageName + ".SpringWebHttpServerDecorator$1",
+    };
+  }
+
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
     return singletonMap(
@@ -66,15 +72,8 @@ public final class HandlerAdapterInstrumentation extends Instrumenter.Default {
       // Name the parent span based on the matching pattern
       // This is likely the servlet.request span.
       final Scope parentScope = GlobalTracer.get().scopeManager().active();
-      if (parentScope != null && request != null) {
+      if (parentScope != null) {
-        final String method = request.getMethod();
+        DECORATE.onRequest(parentScope.span(), request);
-        final Object bestMatchingPattern =
-            request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
-        if (method != null && bestMatchingPattern != null) {
-          final String resourceName = method + " " + bestMatchingPattern;
-          parentScope.span().setTag(DDTags.RESOURCE_NAME, resourceName);
-          parentScope.span().setTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_SERVER);
-        }
       }
 
       // Now create a span for controller execution.
@@ -105,33 +104,18 @@ public final class HandlerAdapterInstrumentation extends Instrumenter.Default {
         methodName = "<annotation>";
       }
 
-      String className = clazz.getSimpleName();
+      final String operationName = DECORATE.spanNameForClass(clazz) + "." + methodName;
-      if (className.isEmpty()) {
-        className = clazz.getName();
-        if (clazz.getPackage() != null) {
-          final String pkgName = clazz.getPackage().getName();
-          if (!pkgName.isEmpty()) {
-            className = clazz.getName().replace(pkgName, "").substring(1);
-          }
-        }
-      }
 
-      final String operationName = className + "." + methodName;
+      final Scope scope = GlobalTracer.get().buildSpan(operationName).startActive(true);
-
+      DECORATE.afterStart(scope);
-      return GlobalTracer.get()
+      return scope;
-          .buildSpan(operationName)
-          .withTag(Tags.COMPONENT.getKey(), "spring-web-controller")
-          .startActive(true);
     }
 
     @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
     public static void stopSpan(
         @Advice.Enter final Scope scope, @Advice.Thrown final Throwable throwable) {
-      if (throwable != null) {
+      DECORATE.onError(scope, throwable);
-        final Span span = scope.span();
+      DECORATE.beforeFinish(scope);
-        Tags.ERROR.set(span, true);
-        span.log(singletonMap(ERROR_OBJECT, throwable));
-      }
       scope.close();
     }
   }

dd-java-agent/instrumentation/spring-web/src/main/java/datadog/trace/instrumentation/springweb/SpringWebHttpServerDecorator.java

@@ -0,0 +1,87 @@
+package datadog.trace.instrumentation.springweb;
+
+import datadog.trace.agent.decorator.HttpServerDecorator;
+import datadog.trace.api.DDSpanTypes;
+import datadog.trace.api.DDTags;
+import io.opentracing.Scope;
+import io.opentracing.Span;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.servlet.HandlerMapping;
+import org.springframework.web.servlet.ModelAndView;
+
+@Slf4j
+public class SpringWebHttpServerDecorator
+    extends HttpServerDecorator<HttpServletRequest, HttpServletResponse> {
+  public static final SpringWebHttpServerDecorator DECORATE = new SpringWebHttpServerDecorator();
+  public static final SpringWebHttpServerDecorator DECORATE_RENDER =
+      new SpringWebHttpServerDecorator() {
+        @Override
+        protected String component() {
+          return "spring-webmvc";
+        }
+      };
+
+  @Override
+  protected String[] instrumentationNames() {
+    return new String[] {"spring-web"};
+  }
+
+  @Override
+  protected String component() {
+    return "spring-web-controller";
+  }
+
+  @Override
+  protected String method(final HttpServletRequest httpServletRequest) {
+    return httpServletRequest.getMethod();
+  }
+
+  @Override
+  protected String url(final HttpServletRequest httpServletRequest) {
+    return httpServletRequest.getRequestURL().toString();
+  }
+
+  @Override
+  protected String hostname(final HttpServletRequest httpServletRequest) {
+    return httpServletRequest.getServerName();
+  }
+
+  @Override
+  protected Integer port(final HttpServletRequest httpServletRequest) {
+    return httpServletRequest.getServerPort();
+  }
+
+  @Override
+  protected Integer status(final HttpServletResponse httpServletResponse) {
+    return httpServletResponse.getStatus();
+  }
+
+  @Override
+  public Span onRequest(final Span span, final HttpServletRequest request) {
+    super.onRequest(span, request);
+    if (request != null) {
+      final String method = request.getMethod();
+      final Object bestMatchingPattern =
+          request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
+      if (method != null && bestMatchingPattern != null) {
+        final String resourceName = method + " " + bestMatchingPattern;
+        span.setTag(DDTags.RESOURCE_NAME, resourceName);
+        span.setTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_SERVER);
+      }
+    }
+    return span;
+  }
+
+  public Scope onRender(final Scope scope, final ModelAndView mv) {
+    final Span span = scope.span();
+    if (mv.getViewName() != null) {
+      span.setTag("view.name", mv.getViewName());
+    }
+    if (mv.getView() != null) {
+      span.setTag("view.type", mv.getView().getClass().getName());
+    }
+    return scope;
+  }
+}

dd-java-agent/instrumentation/spring-web/src/test/groovy/test/SpringBootBasedTest.groovy

@@ -368,10 +368,12 @@ class SpringBootBasedTest extends AgentTestRunner {
       serviceName "unnamed-java-app"
       operationName name
       resourceName name
+      spanType DDSpanTypes.HTTP_SERVER
       childOf(trace.span(0))
       errored errorType != null
       tags {
         "$Tags.COMPONENT.key" "spring-web-controller"
+        "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
         if (errorType) {
           "error.msg" String
           errorTags(errorType)

dd-java-agent/instrumentation/spring-webflux/src/main/java/datadog/trace/instrumentation/springwebflux/AbstractWebfluxInstrumentation.java

@@ -4,8 +4,6 @@ import datadog.trace.agent.tooling.Instrumenter;
 
 public abstract class AbstractWebfluxInstrumentation extends Instrumenter.Default {
 
-  public static final String PACKAGE = AbstractWebfluxInstrumentation.class.getPackage().getName();
-
   public AbstractWebfluxInstrumentation(final String... additionalNames) {
     super("spring-webflux", additionalNames);
   }
@@ -13,11 +11,14 @@ public abstract class AbstractWebfluxInstrumentation extends Instrumenter.Defaul
   @Override
   public String[] helperClassNames() {
     return new String[] {
+      "datadog.trace.agent.decorator.BaseDecorator",
+      "datadog.trace.agent.decorator.ServerDecorator",
+      packageName + ".SpringWebfluxHttpServerDecorator",
       // Some code comes from reactor's instrumentation's helper
       "datadog.trace.instrumentation.reactor.core.ReactorCoreAdviceUtils",
       "datadog.trace.instrumentation.reactor.core.ReactorCoreAdviceUtils$TracingSubscriber",
-      PACKAGE + ".AdviceUtils",
+      packageName + ".AdviceUtils",
-      PACKAGE + ".RouteOnSuccessOrError"
+      packageName + ".RouteOnSuccessOrError"
     };
   }
 }

dd-java-agent/instrumentation/spring-webflux/src/main/java/datadog/trace/instrumentation/springwebflux/DispatcherHandlerInstrumentation.java

@@ -31,6 +31,6 @@ public final class DispatcherHandlerInstrumentation extends AbstractWebfluxInstr
             .and(takesArgument(0, named("org.springframework.web.server.ServerWebExchange")))
             .and(takesArguments(1)),
         // Cannot reference class directly here because it would lead to class load failure on Java7
-        PACKAGE + ".DispatcherHandlerAdvice");
+        packageName + ".DispatcherHandlerAdvice");
   }
 }

dd-java-agent/instrumentation/spring-webflux/src/main/java/datadog/trace/instrumentation/springwebflux/HandlerAdapterInstrumentation.java

@@ -38,6 +38,6 @@ public final class HandlerAdapterInstrumentation extends AbstractWebfluxInstrume
             .and(takesArgument(1, named("java.lang.Object")))
             .and(takesArguments(2)),
         // Cannot reference class directly here because it would lead to class load failure on Java7
-        PACKAGE + ".HandlerAdapterAdvice");
+        packageName + ".HandlerAdapterAdvice");
   }
 }

dd-java-agent/instrumentation/spring-webflux/src/main/java/datadog/trace/instrumentation/springwebflux/RouterFunctionInstrumentation.java

@@ -45,6 +45,6 @@ public final class RouterFunctionInstrumentation extends AbstractWebfluxInstrume
                     0, named("org.springframework.web.reactive.function.server.ServerRequest")))
             .and(takesArguments(1)),
         // Cannot reference class directly here because it would lead to class load failure on Java7
-        PACKAGE + ".RouterFunctionAdvice");
+        packageName + ".RouterFunctionAdvice");
   }
 }

dd-java-agent/instrumentation/spring-webflux/src/main/java8/datadog/trace/instrumentation/springwebflux/AdviceUtils.java

@@ -1,5 +1,7 @@
 package datadog.trace.instrumentation.springwebflux;
 
+import static datadog.trace.instrumentation.springwebflux.SpringWebfluxHttpServerDecorator.DECORATE;
+
 import datadog.trace.instrumentation.reactor.core.ReactorCoreAdviceUtils;
 import io.opentracing.Span;
 import lombok.extern.slf4j.Slf4j;
@@ -11,10 +13,10 @@ public class AdviceUtils {
 
   public static final String SPAN_ATTRIBUTE = "datadog.trace.instrumentation.springwebflux.Span";
   public static final String PARENT_SPAN_ATTRIBUTE =
-    "datadog.trace.instrumentation.springwebflux.ParentSpan";
+      "datadog.trace.instrumentation.springwebflux.ParentSpan";
 
   public static String parseOperationName(final Object handler) {
-    final String className = parseClassName(handler.getClass());
+    final String className = DECORATE.spanNameForClass(handler.getClass());
     final String operationName;
     final int lambdaIdx = className.indexOf("$$Lambda$");
 
@@ -26,29 +28,15 @@ public class AdviceUtils {
     return operationName;
   }
 
-  public static String parseClassName(final Class clazz) {
+  public static void finishSpanIfPresent(
-    String className = clazz.getSimpleName();
+      final ServerWebExchange exchange, final Throwable throwable) {
-    if (className.isEmpty()) {
+    ReactorCoreAdviceUtils.finishSpanIfPresent(
-      className = clazz.getName();
+        (Span) exchange.getAttributes().remove(SPAN_ATTRIBUTE), throwable);
-      if (clazz.getPackage() != null) {
-        final String pkgName = clazz.getPackage().getName();
-        if (!pkgName.isEmpty()) {
-          className = clazz.getName().replace(pkgName, "").substring(1);
-        }
-      }
-    }
-    return className;
   }
 
   public static void finishSpanIfPresent(
-    final ServerWebExchange exchange, final Throwable throwable) {
+      final ServerRequest serverRequest, final Throwable throwable) {
     ReactorCoreAdviceUtils.finishSpanIfPresent(
-      (Span) exchange.getAttributes().remove(SPAN_ATTRIBUTE), throwable);
+        (Span) serverRequest.attributes().remove(SPAN_ATTRIBUTE), throwable);
-  }
-
-  public static void finishSpanIfPresent(
-    final ServerRequest serverRequest, final Throwable throwable) {
-    ReactorCoreAdviceUtils.finishSpanIfPresent(
-      (Span) serverRequest.attributes().remove(SPAN_ATTRIBUTE), throwable);
   }
 }

dd-java-agent/instrumentation/spring-webflux/src/main/java8/datadog/trace/instrumentation/springwebflux/DispatcherHandlerAdvice.java

@@ -1,12 +1,11 @@
 package datadog.trace.instrumentation.springwebflux;
 
-import datadog.trace.api.DDSpanTypes;
+import static datadog.trace.instrumentation.springwebflux.SpringWebfluxHttpServerDecorator.DECORATE;
-import datadog.trace.api.DDTags;
+
 import datadog.trace.context.TraceScope;
 import datadog.trace.instrumentation.reactor.core.ReactorCoreAdviceUtils;
 import io.opentracing.Scope;
 import io.opentracing.Span;
-import io.opentracing.tag.Tags;
 import io.opentracing.util.GlobalTracer;
 import java.util.function.Function;
 import net.bytebuddy.asm.Advice;
@@ -29,12 +28,8 @@ public class DispatcherHandlerAdvice {
     if (parentSpan != null) {
       exchange.getAttributes().put(AdviceUtils.PARENT_SPAN_ATTRIBUTE, parentSpan);
     }
-    final Scope scope =
+    final Scope scope = GlobalTracer.get().buildSpan("DispatcherHandler.handle").startActive(false);
-      GlobalTracer.get()
+    DECORATE.afterStart(scope);
-        .buildSpan("DispatcherHandler.handle")
-        .withTag(Tags.COMPONENT.getKey(), "spring-webflux-controller")
-        .withTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_SERVER)
-        .startActive(false);
     ((TraceScope) scope).setAsyncPropagation(true);
     exchange.getAttributes().put(AdviceUtils.SPAN_ATTRIBUTE, scope.span());
     return scope;
@@ -42,13 +37,13 @@ public class DispatcherHandlerAdvice {
 
   @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
   public static void methodExit(
-    @Advice.Enter final Scope scope,
+      @Advice.Enter final Scope scope,
-    @Advice.Thrown final Throwable throwable,
+      @Advice.Thrown final Throwable throwable,
-    @Advice.Argument(0) final ServerWebExchange exchange,
+      @Advice.Argument(0) final ServerWebExchange exchange,
-    @Advice.Return(readOnly = false) Mono<Object> mono) {
+      @Advice.Return(readOnly = false) Mono<Object> mono) {
     if (throwable == null && mono != null) {
       final Function<? super Mono<Object>, ? extends Publisher<Object>> function =
-        ReactorCoreAdviceUtils.finishSpanNextOrError();
+          ReactorCoreAdviceUtils.finishSpanNextOrError();
       mono = ReactorCoreAdviceUtils.setPublisherSpan(mono, scope.span());
     } else if (throwable != null) {
       AdviceUtils.finishSpanIfPresent(exchange, throwable);

dd-java-agent/instrumentation/spring-webflux/src/main/java8/datadog/trace/instrumentation/springwebflux/HandlerAdapterAdvice.java

@@ -1,5 +1,7 @@
 package datadog.trace.instrumentation.springwebflux;
 
+import static datadog.trace.instrumentation.springwebflux.SpringWebfluxHttpServerDecorator.DECORATE;
+
 import datadog.trace.api.DDTags;
 import datadog.trace.context.TraceScope;
 import io.opentracing.Scope;
@@ -15,8 +17,8 @@ public class HandlerAdapterAdvice {
 
   @Advice.OnMethodEnter(suppress = Throwable.class)
   public static Scope methodEnter(
-    @Advice.Argument(0) final ServerWebExchange exchange,
+      @Advice.Argument(0) final ServerWebExchange exchange,
-    @Advice.Argument(1) final Object handler) {
+      @Advice.Argument(1) final Object handler) {
 
     Scope scope = null;
     final Span span = exchange.getAttribute(AdviceUtils.SPAN_ATTRIBUTE);
@@ -27,11 +29,8 @@ public class HandlerAdapterAdvice {
       if (handler instanceof HandlerMethod) {
         // Special case for requests mapped with annotations
         final HandlerMethod handlerMethod = (HandlerMethod) handler;
-        final Class handlerClass = handlerMethod.getMethod().getDeclaringClass();
+        operationName = DECORATE.spanNameForMethod(handlerMethod.getMethod());
-
+        handlerType = handlerMethod.getMethod().getDeclaringClass().getName();
-        operationName =
-          AdviceUtils.parseClassName(handlerClass) + "." + handlerMethod.getMethod().getName();
-        handlerType = handlerClass.getName();
       } else {
         operationName = AdviceUtils.parseOperationName(handler);
         handlerType = handler.getClass().getName();
@@ -46,11 +45,11 @@ public class HandlerAdapterAdvice {
 
     final Span parentSpan = exchange.getAttribute(AdviceUtils.PARENT_SPAN_ATTRIBUTE);
     final PathPattern bestPattern =
-      exchange.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
+        exchange.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
     if (parentSpan != null && bestPattern != null) {
       parentSpan.setTag(
-        DDTags.RESOURCE_NAME,
+          DDTags.RESOURCE_NAME,
-        exchange.getRequest().getMethodValue() + " " + bestPattern.getPatternString());
+          exchange.getRequest().getMethodValue() + " " + bestPattern.getPatternString());
     }
 
     return scope;
@@ -58,9 +57,9 @@ public class HandlerAdapterAdvice {
 
   @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
   public static void methodExit(
-    @Advice.Argument(0) final ServerWebExchange exchange,
+      @Advice.Argument(0) final ServerWebExchange exchange,
-    @Advice.Enter final Scope scope,
+      @Advice.Enter final Scope scope,
-    @Advice.Thrown final Throwable throwable) {
+      @Advice.Thrown final Throwable throwable) {
     if (throwable != null) {
       AdviceUtils.finishSpanIfPresent(exchange, throwable);
     }

dd-java-agent/instrumentation/spring-webflux/src/main/java8/datadog/trace/instrumentation/springwebflux/SpringWebfluxHttpServerDecorator.java

@@ -0,0 +1,26 @@
+package datadog.trace.instrumentation.springwebflux;
+
+import datadog.trace.agent.decorator.ServerDecorator;
+import datadog.trace.api.DDSpanTypes;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class SpringWebfluxHttpServerDecorator extends ServerDecorator {
+  public static final SpringWebfluxHttpServerDecorator DECORATE =
+      new SpringWebfluxHttpServerDecorator();
+
+  @Override
+  protected String[] instrumentationNames() {
+    return new String[] {"spring-webflux"};
+  }
+
+  @Override
+  protected String spanType() {
+    return DDSpanTypes.HTTP_SERVER;
+  }
+
+  @Override
+  protected String component() {
+    return "spring-webflux-controller";
+  }
+}

dd-java-agent/instrumentation/spring-webflux/src/test/groovy/SpringWebfluxTest.groovy

@@ -62,6 +62,7 @@ class SpringWebfluxTest extends AgentTestRunner {
           childOf(span(1))
           tags {
             "$Tags.COMPONENT.key" "spring-webflux-controller"
+            "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             if (annotatedMethod == null) {
               // Functional API
               "request.predicate" "(GET && $urlPathWithVariables)"
@@ -135,6 +136,7 @@ class SpringWebfluxTest extends AgentTestRunner {
           childOf(span(1))
           tags {
             "$Tags.COMPONENT.key" "spring-webflux-controller"
+            "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             if (annotatedMethod == null) {
               // Functional API
               "request.predicate" "(GET && $urlPathWithVariables)"
@@ -234,6 +236,7 @@ class SpringWebfluxTest extends AgentTestRunner {
           errored true
           tags {
             "$Tags.COMPONENT.key" "spring-webflux-controller"
+            "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "handler.type" "org.springframework.web.reactive.resource.ResourceWebHandler"
             errorTags(ResponseStatusException, String)
             defaultTags()
@@ -265,6 +268,7 @@ class SpringWebfluxTest extends AgentTestRunner {
           childOf(span(1))
           tags {
             "$Tags.COMPONENT.key" "spring-webflux-controller"
+            "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "request.predicate" "(POST && /echo)"
             "handler.type" { String tagVal ->
               return tagVal.contains(EchoHandlerFunction.getName())
@@ -348,6 +352,7 @@ class SpringWebfluxTest extends AgentTestRunner {
           errored true
           tags {
             "$Tags.COMPONENT.key" "spring-webflux-controller"
+            "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             if (annotatedMethod == null) {
               // Functional API
               "request.predicate" "(GET && $urlPathWithVariables)"
@@ -412,6 +417,7 @@ class SpringWebfluxTest extends AgentTestRunner {
           childOf(span(0))
           tags {
             "$Tags.COMPONENT.key" "spring-webflux-controller"
+            "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "request.predicate" "(GET && /double-greet-redirect)"
             "handler.type" { String tagVal ->
               return (tagVal.contains(INNER_HANDLER_FUNCTION_CLASS_TAG_PREFIX)
@@ -429,6 +435,7 @@ class SpringWebfluxTest extends AgentTestRunner {
           childOf(span(1))
           tags {
             "$Tags.COMPONENT.key" "spring-webflux-controller"
+            "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
             "request.predicate" "(GET && /double-greet)"
             "handler.type" { String tagVal ->
               return tagVal.contains(INNER_HANDLER_FUNCTION_CLASS_TAG_PREFIX)
@@ -485,6 +492,7 @@ class SpringWebfluxTest extends AgentTestRunner {
             childOf(span(1))
             tags {
               "$Tags.COMPONENT.key" "spring-webflux-controller"
+              "$Tags.SPAN_KIND.key" Tags.SPAN_KIND_SERVER
               if (annotatedMethod == null) {
                 // Functional API
                 "request.predicate" "(GET && $urlPathWithVariables)"