Back off on Propagator in Brave and Otel auto-configurations

This also fixes the bug that both auto-configurations couldn't be used
together.

Closes gh-49183

Author: mhalbritter

module/spring-boot-micrometer-tracing-brave/src/main/java/org/springframework/boot/micrometer/tracing/brave/autoconfigure/BraveAutoConfiguration.java

@@ -39,6 +39,7 @@
 import io.micrometer.tracing.exporter.SpanExportingPredicate;
 import io.micrometer.tracing.exporter.SpanFilter;
 import io.micrometer.tracing.exporter.SpanReporter;
+import io.micrometer.tracing.propagation.Propagator;
 
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
@@ -166,7 +167,7 @@ BraveTracer braveTracerBridge(brave.Tracer tracer, CurrentTraceContext currentTr
 	}
 
 	@Bean
-	@ConditionalOnMissingBean
+	@ConditionalOnMissingBean(Propagator.class)
 	BravePropagator bravePropagator(Tracing tracing) {
 		return new BravePropagator(tracing);
 	}

module/spring-boot-micrometer-tracing-brave/src/test/java/org/springframework/boot/micrometer/tracing/brave/autoconfigure/BraveAutoConfigurationTests.java

@@ -39,13 +39,15 @@
 import io.micrometer.observation.Observation.Scope;
 import io.micrometer.observation.ObservationRegistry;
 import io.micrometer.tracing.brave.bridge.BraveBaggageManager;
+import io.micrometer.tracing.brave.bridge.BravePropagator;
 import io.micrometer.tracing.brave.bridge.BraveSpanCustomizer;
 import io.micrometer.tracing.brave.bridge.BraveTracer;
 import io.micrometer.tracing.brave.bridge.CompositeSpanHandler;
 import io.micrometer.tracing.brave.bridge.W3CPropagation;
 import io.micrometer.tracing.exporter.SpanExportingPredicate;
 import io.micrometer.tracing.exporter.SpanFilter;
 import io.micrometer.tracing.exporter.SpanReporter;
+import io.micrometer.tracing.propagation.Propagator;
 import org.assertj.core.api.InstanceOfAssertFactories;
 import org.junit.jupiter.api.Test;
 
@@ -126,6 +128,15 @@ void shouldSupplyMicrometerBeans() {
 		this.contextRunner.run((context) -> assertThat(context).hasSingleBean(BraveTracer.class));
 	}
 
+	@Test
+	void shouldNotSupplyBravePropagatorWhenPropagatorBeanIsPresent() {
+		this.contextRunner.withUserConfiguration(PropagatorConfiguration.class).run((context) -> {
+			assertThat(context).hasSingleBean(Propagator.class);
+			assertThat(context).hasBean("customPropagator");
+			assertThat(context).doesNotHaveBean(BravePropagator.class);
+		});
+	}
+
 	@Test
 	void shouldNotSupplyBeansIfBraveIsMissing() {
 		this.contextRunner.withClassLoader(new FilteredClassLoader("brave"))
@@ -535,4 +546,14 @@ io.micrometer.tracing.SpanCustomizer customMicrometerSpanCustomizer() {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class PropagatorConfiguration {
+
+		@Bean
+		Propagator customPropagator() {
+			return mock(Propagator.class);
+		}
+
+	}
+
 }

module/spring-boot-micrometer-tracing-opentelemetry/build.gradle

@@ -49,7 +49,9 @@ dependencies {
 	dockerTestImplementation("org.testcontainers:testcontainers-junit-jupiter")
 
 	testImplementation(project(":core:spring-boot-test"))
+	testImplementation(project(":module:spring-boot-micrometer-tracing-brave"))
 	testImplementation(project(":test-support:spring-boot-test-support"))
+	testImplementation("io.micrometer:micrometer-tracing-bridge-brave")
 	testImplementation("com.squareup.okhttp3:mockwebserver")
 	testImplementation("io.micrometer:micrometer-registry-prometheus")
 	testImplementation("io.opentelemetry:opentelemetry-exporter-common")

module/spring-boot-micrometer-tracing-opentelemetry/src/main/java/org/springframework/boot/micrometer/tracing/opentelemetry/autoconfigure/OpenTelemetryTracingAutoConfiguration.java

@@ -31,6 +31,7 @@
 import io.micrometer.tracing.otel.bridge.OtelTracer;
 import io.micrometer.tracing.otel.bridge.OtelTracer.EventPublisher;
 import io.micrometer.tracing.otel.bridge.Slf4JEventListener;
+import io.micrometer.tracing.propagation.Propagator;
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.metrics.MeterProvider;
 import io.opentelemetry.api.trace.Tracer;
@@ -164,7 +165,7 @@ OtelTracer micrometerOtelTracer(Tracer tracer, EventPublisher eventPublisher,
 	}
 
 	@Bean
-	@ConditionalOnMissingBean
+	@ConditionalOnMissingBean(Propagator.class)
 	OtelPropagator otelPropagator(ContextPropagators contextPropagators, Tracer tracer) {
 		return new OtelPropagator(contextPropagators, tracer);
 	}

module/spring-boot-micrometer-tracing-opentelemetry/src/test/java/org/springframework/boot/micrometer/tracing/opentelemetry/autoconfigure/OpenTelemetryTracingAutoConfigurationTests.java

@@ -27,6 +27,8 @@
 
 import io.micrometer.tracing.SpanCustomizer;
 import io.micrometer.tracing.Tracer.SpanInScope;
+import io.micrometer.tracing.handler.PropagatingReceiverTracingObservationHandler;
+import io.micrometer.tracing.handler.PropagatingSenderTracingObservationHandler;
 import io.micrometer.tracing.otel.bridge.EventListener;
 import io.micrometer.tracing.otel.bridge.OtelCurrentTraceContext;
 import io.micrometer.tracing.otel.bridge.OtelPropagator;
@@ -36,6 +38,7 @@
 import io.micrometer.tracing.otel.bridge.Slf4JBaggageEventListener;
 import io.micrometer.tracing.otel.bridge.Slf4JEventListener;
 import io.micrometer.tracing.otel.propagation.BaggageTextMapPropagator;
+import io.micrometer.tracing.propagation.Propagator;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.MeterProvider;
@@ -63,6 +66,8 @@
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.micrometer.observation.autoconfigure.ObservationAutoConfiguration;
 import org.springframework.boot.micrometer.tracing.autoconfigure.MicrometerTracingAutoConfiguration;
+import org.springframework.boot.micrometer.tracing.brave.autoconfigure.BraveAutoConfiguration;
+import org.springframework.boot.opentelemetry.autoconfigure.OpenTelemetrySdkAutoConfiguration;
 import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.testsupport.classpath.ForkedClassPath;
@@ -89,8 +94,7 @@
 class OpenTelemetryTracingAutoConfigurationTests {
 
 	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
-		.withConfiguration(AutoConfigurations.of(
-				org.springframework.boot.opentelemetry.autoconfigure.OpenTelemetrySdkAutoConfiguration.class,
+		.withConfiguration(AutoConfigurations.of(OpenTelemetrySdkAutoConfiguration.class,
 				OpenTelemetryTracingAutoConfiguration.class));
 
 	@Test
@@ -179,6 +183,29 @@ void shouldBackOffOnCustomBeans() {
 		});
 	}
 
+	@Test
+	void shouldNotSupplyOtelPropagatorWhenPropagatorBeanIsPresent() {
+		this.contextRunner.withUserConfiguration(PropagatorConfiguration.class).run((context) -> {
+			assertThat(context).hasSingleBean(Propagator.class);
+			assertThat(context).hasBean("customPropagator");
+			assertThat(context).doesNotHaveBean(OtelPropagator.class);
+		});
+	}
+
+	@Test
+	void shouldWorkWithBraveAutoConfigurationWhenBothConfigurationsAreOnClasspath() {
+		new ApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(OpenTelemetrySdkAutoConfiguration.class,
+					OpenTelemetryTracingAutoConfiguration.class, BraveAutoConfiguration.class,
+					ObservationAutoConfiguration.class, MicrometerTracingAutoConfiguration.class))
+			.run((context) -> {
+				assertThat(context).hasSingleBean(io.micrometer.tracing.Tracer.class);
+				assertThat(context).hasSingleBean(Propagator.class);
+				assertThat(context).hasSingleBean(PropagatingSenderTracingObservationHandler.class);
+				assertThat(context).hasSingleBean(PropagatingReceiverTracingObservationHandler.class);
+			});
+	}
+
 	@Test
 	void shouldSetupDefaultResourceAttributes() {
 		this.contextRunner
@@ -518,6 +545,16 @@ SpanCustomizer customSpanCustomizer() {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class PropagatorConfiguration {
+
+		@Bean
+		Propagator customPropagator() {
+			return mock(Propagator.class);
+		}
+
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	private static final class SdkTracerProviderCustomizationConfiguration {