Bring back webflux client instrumentation (#406)

instrumentation/spring-webflux-5.0/src/main/java/io/opentelemetry/auto/instrumentation/springwebflux/client/WebClientFilterInstrumentation.java

@@ -22,14 +22,14 @@ import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.isPublic;
 import static net.bytebuddy.matcher.ElementMatchers.named;
 
+import com.google.auto.service.AutoService;
 import io.opentelemetry.auto.tooling.Instrumenter;
 import java.util.Map;
 import net.bytebuddy.description.method.MethodDescription;
 import net.bytebuddy.description.type.TypeDescription;
 import net.bytebuddy.matcher.ElementMatcher;
 
-// FIXME this instrumentation is not currently reliable, see DefaultWebClientAdvice
+@AutoService(Instrumenter.class)
-// @AutoService(Instrumenter.class)
 public class WebClientFilterInstrumentation extends Instrumenter.Default {
 
   public WebClientFilterInstrumentation() {

instrumentation/spring-webflux-5.0/src/main/java8/io/opentelemetry/auto/instrumentation/springwebflux/client/WebClientTracingFilter.java

@@ -18,6 +18,7 @@ package io.opentelemetry.auto.instrumentation.springwebflux.client;
 import static io.opentelemetry.auto.instrumentation.springwebflux.client.HttpHeadersInjectAdapter.SETTER;
 import static io.opentelemetry.auto.instrumentation.springwebflux.client.SpringWebfluxHttpClientDecorator.DECORATE;
 import static io.opentelemetry.auto.instrumentation.springwebflux.client.SpringWebfluxHttpClientDecorator.TRACER;
+import static io.opentelemetry.trace.Span.Kind.CLIENT;
 
 import io.grpc.Context;
 import io.opentelemetry.OpenTelemetry;
@@ -38,13 +39,13 @@ public class WebClientTracingFilter implements ExchangeFilterFunction {
 
   @Override
   public Mono<ClientResponse> filter(final ClientRequest request, final ExchangeFunction next) {
-    final Span span = TRACER.spanBuilder("http.request").startSpan();
+    final Span span =
+        TRACER.spanBuilder(DECORATE.spanNameForRequest(request)).setSpanKind(CLIENT).startSpan();
     DECORATE.afterStart(span);
 
     try (final Scope scope = TRACER.withSpan(span)) {
       final ClientRequest mutatedRequest =
           ClientRequest.from(request)
-              .attribute(Span.class.getName(), span)
               .headers(
                   httpHeaders ->
                       OpenTelemetry.getPropagators()

instrumentation/spring-webflux-5.0/src/main/java8/io/opentelemetry/auto/instrumentation/springwebflux/server/AdviceUtils.java

@@ -27,7 +27,6 @@ import java.util.function.Function;
 import lombok.extern.slf4j.Slf4j;
 import org.reactivestreams.Publisher;
 import org.reactivestreams.Subscription;
-import org.springframework.web.reactive.function.client.ClientRequest;
 import org.springframework.web.reactive.function.server.ServerRequest;
 import org.springframework.web.server.ServerWebExchange;
 import reactor.core.CoreSubscriber;
@@ -85,13 +84,6 @@ public class AdviceUtils {
     }
   }
 
-  public static void finishSpanIfPresent(
-      final ClientRequest clientRequest, final Throwable throwable) {
-    if (clientRequest != null) {
-      finishSpanIfPresentInAttributes(clientRequest.attributes(), throwable);
-    }
-  }
-
   private static void finishSpanIfPresentInAttributes(
       final Map<String, Object> attributes, final Throwable throwable) {
 

instrumentation/spring-webflux-5.0/src/test/groovy/client/SpringWebfluxHttpClientTest.groovy

@@ -22,14 +22,10 @@ import io.opentelemetry.auto.test.base.HttpClientTest
 import org.springframework.http.HttpMethod
 import org.springframework.web.reactive.function.client.ClientResponse
 import org.springframework.web.reactive.function.client.WebClient
-import spock.lang.Ignore
 import spock.lang.Timeout
 
 import static io.opentelemetry.trace.Span.Kind.CLIENT
 
-// FIXME this instrumentation is not currently reliable and so is currently disabled
-// see DefaultWebClientInstrumentation and DefaultWebClientAdvice
-@Ignore
 @Timeout(5)
 class SpringWebfluxHttpClientTest extends HttpClientTest {
 
@@ -54,7 +50,7 @@ class SpringWebfluxHttpClientTest extends HttpClientTest {
     if (!exception) {
       trace.span(index + 1) {
         childOf(trace.span(index))
-        operationName "netty.client.request"
+        operationName "HTTP $method"
         spanKind CLIENT
         errored exception != null
         tags {