Merge pull request #35165 from jonatan-ivanov

* pr/35165:
  Support Brave's joint spans

Closes gh-35165

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/tracing/BraveAutoConfiguration.java

@@ -54,12 +54,14 @@ import io.micrometer.tracing.exporter.SpanFilter;
 import io.micrometer.tracing.exporter.SpanReporter;
 
 import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.actuate.autoconfigure.tracing.TracingProperties.Propagation.PropagationType;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.context.properties.IncompatibleConfigurationException;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
@@ -71,6 +73,7 @@ import org.springframework.core.env.Environment;
  *
  * @author Moritz Halbritter
  * @author Marcin Grzejszczak
+ * @author Jonatan Ivanov
  * @since 3.0.0
  */
 @AutoConfiguration(before = MicrometerTracingAutoConfiguration.class)
@@ -97,14 +100,19 @@ public class BraveAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	public Tracing braveTracing(Environment environment, List<SpanHandler> spanHandlers,
+	public Tracing braveTracing(Environment environment, TracingProperties properties, List<SpanHandler> spanHandlers,
 			List<TracingCustomizer> tracingCustomizers, CurrentTraceContext currentTraceContext,
 			Factory propagationFactory, Sampler sampler) {
+		if (properties.getPropagation().getType() == PropagationType.W3C
+				&& properties.getBrave().isSpanJoiningSupported()) {
+			throw new IncompatibleConfigurationException("management.tracing.propagation.type",
+					"management.tracing.brave.span-joining-supported");
+		}
 		String applicationName = environment.getProperty("spring.application.name", DEFAULT_APPLICATION_NAME);
 		Builder builder = Tracing.newBuilder()
 			.currentTraceContext(currentTraceContext)
 			.traceId128Bit(true)
-			.supportsJoin(false)
+			.supportsJoin(properties.getBrave().isSpanJoiningSupported())
 			.propagationFactory(propagationFactory)
 			.sampler(sampler)
 			.localServiceName(applicationName);

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/tracing/TracingProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,6 +25,7 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
  * Configuration properties for tracing.
  *
  * @author Moritz Halbritter
+ * @author Jonatan Ivanov
  * @since 3.0.0
  */
 @ConfigurationProperties("management.tracing")
@@ -50,6 +51,11 @@ public class TracingProperties {
 	 */
 	private final Propagation propagation = new Propagation();
 
+	/**
+	 * Brave configuration.
+	 */
+	private final Brave brave = new Brave();
+
 	public boolean isEnabled() {
 		return this.enabled;
 	}
@@ -70,6 +76,10 @@ public class TracingProperties {
 		return this.propagation;
 	}
 
+	public Brave getBrave() {
+		return this.brave;
+	}
+
 	public static class Sampling {
 
 		/**
@@ -194,4 +204,23 @@ public class TracingProperties {
 
 	}
 
+	public static class Brave {
+
+		/**
+		 * Whether the propagation type and tracing backend support sharing the span ID
+		 * between client and server spans. Requires B3 propagation and a compatible
+		 * backend.
+		 */
+		private boolean spanJoiningSupported = false;
+
+		public boolean isSpanJoiningSupported() {
+			return this.spanJoiningSupported;
+		}
+
+		public void setSpanJoiningSupported(boolean spanJoiningSupported) {
+			this.spanJoiningSupported = spanJoiningSupported;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/tracing/BraveAutoConfigurationTests.java

@@ -43,6 +43,7 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.actuate.autoconfigure.tracing.BraveAutoConfigurationTests.SpanHandlerConfiguration.AdditionalSpanHandler;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.context.properties.IncompatibleConfigurationException;
 import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
@@ -50,12 +51,14 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.core.annotation.Order;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link BraveAutoConfiguration}.
  *
  * @author Moritz Halbritter
+ * @author Jonatan Ivanov
  */
 class BraveAutoConfigurationTests {
 
@@ -216,17 +219,45 @@ class BraveAutoConfigurationTests {
 	}
 
 	@Test
-	void shouldNotSupportJoinedSpans() {
+	void shouldNotSupportJoinedSpansByDefault() {
 		this.contextRunner.run((context) -> {
 			Tracing tracing = context.getBean(Tracing.class);
 			Span parentSpan = tracing.tracer().nextSpan();
 			Span childSpan = tracing.tracer().joinSpan(parentSpan.context());
-			assertThat(parentSpan.context().traceIdString()).isEqualTo(childSpan.context().traceIdString());
-			assertThat(parentSpan.context().spanIdString()).isEqualTo(childSpan.context().parentIdString());
-			assertThat(parentSpan.context().spanIdString()).isNotEqualTo(childSpan.context().spanIdString());
+			assertThat(childSpan.context().traceIdString()).isEqualTo(parentSpan.context().traceIdString());
+			assertThat(childSpan.context().spanIdString()).isNotEqualTo(parentSpan.context().spanIdString());
+			assertThat(childSpan.context().parentIdString()).isEqualTo(parentSpan.context().spanIdString());
+			assertThat(parentSpan.context().parentIdString()).isNull();
 		});
 	}
 
+	@Test
+	void shouldSupportJoinedSpansIfB3UsedAndBackendSupportsIt() {
+		this.contextRunner
+			.withPropertyValues("management.tracing.propagation.type=B3",
+					"management.tracing.brave.span-joining-supported=true")
+			.run((context) -> {
+				Tracing tracing = context.getBean(Tracing.class);
+				Span parentSpan = tracing.tracer().nextSpan();
+				Span childSpan = tracing.tracer().joinSpan(parentSpan.context());
+				assertThat(childSpan.context().traceIdString()).isEqualTo(parentSpan.context().traceIdString());
+				assertThat(childSpan.context().spanIdString()).isEqualTo(parentSpan.context().spanIdString());
+				assertThat(childSpan.context().parentIdString()).isNull();
+				assertThat(parentSpan.context().parentIdString()).isNull();
+			});
+	}
+
+	@Test
+	void shouldFailIfSupportJoinedSpansIsEnabledAndW3cIsChosen() {
+		this.contextRunner
+			.withPropertyValues("management.tracing.propagation.type=W3C",
+					"management.tracing.brave.span-joining-supported=true")
+			.run((context) -> assertThatThrownBy(() -> context.getBean(Tracing.class)).rootCause()
+				.isExactlyInstanceOf(IncompatibleConfigurationException.class)
+				.hasMessage(
+						"The following configuration properties have incompatible values: [management.tracing.propagation.type, management.tracing.brave.span-joining-supported]"));
+	}
+
 	@Test
 	@SuppressWarnings("rawtypes")
 	void compositeSpanHandlerShouldBeFirstSpanHandler() {