Use early static registration of EventPublishingContextWrapper

Add `OpenTelemetryEventPublisherApplicationListener` which uses a single
static `ContextStorage` wrapper which gets applied as early as possible.
The static wrapper is then updated as beans come and go.

By adding the wrapper early, we hope to avoid silent failures which
can occur if the `ContextStorage` gets initialized before the wrapper
is added.

Closes gh-41439

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

@@ -24,7 +24,6 @@ import io.micrometer.tracing.exporter.SpanFilter;
 import io.micrometer.tracing.exporter.SpanReporter;
 import io.micrometer.tracing.otel.bridge.CompositeSpanExporter;
 import io.micrometer.tracing.otel.bridge.EventListener;
-import io.micrometer.tracing.otel.bridge.EventPublishingContextWrapper;
 import io.micrometer.tracing.otel.bridge.OtelBaggageManager;
 import io.micrometer.tracing.otel.bridge.OtelCurrentTraceContext;
 import io.micrometer.tracing.otel.bridge.OtelPropagator;
@@ -35,7 +34,6 @@ import io.micrometer.tracing.otel.bridge.Slf4JEventListener;
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.metrics.MeterProvider;
 import io.opentelemetry.api.trace.Tracer;
-import io.opentelemetry.context.ContextStorage;
 import io.opentelemetry.context.propagation.ContextPropagators;
 import io.opentelemetry.context.propagation.TextMapPropagator;
 import io.opentelemetry.sdk.resources.Resource;
@@ -164,8 +162,7 @@ public class OpenTelemetryAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	OtelCurrentTraceContext otelCurrentTraceContext(EventPublisher publisher) {
-		ContextStorage.addWrapper(new EventPublishingContextWrapper(publisher));
+	OtelCurrentTraceContext otelCurrentTraceContext() {
 		return new OtelCurrentTraceContext();
 	}
 

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

@@ -0,0 +1,178 @@
+/*
+ * Copyright 2012-2024 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.autoconfigure.tracing;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.UnaryOperator;
+
+import io.micrometer.tracing.otel.bridge.EventPublishingContextWrapper;
+import io.micrometer.tracing.otel.bridge.OtelTracer.EventPublisher;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.context.ContextStorage;
+import io.opentelemetry.context.Scope;
+
+import org.springframework.boot.context.event.ApplicationStartingEvent;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationEvent;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.event.ContextClosedEvent;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.GenericApplicationListener;
+import org.springframework.core.Ordered;
+import org.springframework.core.ResolvableType;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+
+/**
+ * {@link ApplicationListener} to add an OpenTelemetry {@link ContextStorage} wrapper for
+ * {@link EventPublisher} bean support. A single {@link ContextStorage} wrapper is added
+ * as early as possible then updated with {@link EventPublisher} beans as needed.
+ *
+ * @author Phillip Webb
+ */
+class OpenTelemetryEventPublisherApplicationListener implements GenericApplicationListener {
+
+	private static final boolean OTEL_CONTEXT_PRESENT = ClassUtils.isPresent("io.opentelemetry.context.ContextStorage",
+			null);
+
+	private static final boolean MICROMETER_OTEL_PRESENT = ClassUtils
+		.isPresent("io.micrometer.tracing.otel.bridge.OtelTracer", null);
+
+	@Override
+	public int getOrder() {
+		return Ordered.HIGHEST_PRECEDENCE;
+	}
+
+	@Override
+	public boolean supportsEventType(ResolvableType eventType) {
+		Class<?> type = eventType.getRawClass();
+		return (type != null) && (ApplicationStartingEvent.class.isAssignableFrom(type)
+				|| ContextRefreshedEvent.class.isAssignableFrom(type)
+				|| ContextClosedEvent.class.isAssignableFrom(type));
+	}
+
+	@Override
+	public void onApplicationEvent(ApplicationEvent event) {
+		if (!OTEL_CONTEXT_PRESENT || !MICROMETER_OTEL_PRESENT) {
+			return;
+		}
+		if (event instanceof ApplicationStartingEvent) {
+			EventPublisherBeansContextWrapper.addWrapperIfNecessary();
+		}
+		if (event instanceof ContextRefreshedEvent contextRefreshedEvent) {
+			ApplicationContext applicationContext = contextRefreshedEvent.getApplicationContext();
+			List<EventPublishingContextWrapper> publishers = applicationContext
+				.getBeansOfType(EventPublisher.class, true, false)
+				.values()
+				.stream()
+				.map(EventPublishingContextWrapper::new)
+				.toList();
+			EventPublisherBeansContextWrapper.instance.put(applicationContext, publishers);
+		}
+		if (event instanceof ContextClosedEvent contextClosedEvent) {
+			EventPublisherBeansContextWrapper.instance.remove(contextClosedEvent.getApplicationContext());
+		}
+	}
+
+	/**
+	 * The single {@link ContextStorage} wrapper that delegates to {@link EventPublisher}
+	 * beans.
+	 */
+	static class EventPublisherBeansContextWrapper implements UnaryOperator<ContextStorage> {
+
+		private static final AtomicBoolean added = new AtomicBoolean();
+
+		private static final EventPublisherBeansContextWrapper instance = new EventPublisherBeansContextWrapper();
+
+		private final MultiValueMap<ApplicationContext, EventPublishingContextWrapper> publishers = new LinkedMultiValueMap<>();
+
+		private volatile ContextStorage delegate;
+
+		static void addWrapperIfNecessary() {
+			if (added.compareAndSet(false, true)) {
+				ContextStorage.addWrapper(instance);
+			}
+		}
+
+		@Override
+		public ContextStorage apply(ContextStorage contextStorage) {
+			return new EventPublisherBeansContextStorage(contextStorage);
+		}
+
+		void put(ApplicationContext applicationContext, List<EventPublishingContextWrapper> publishers) {
+			synchronized (this) {
+				this.publishers.addAll(applicationContext, publishers);
+				this.delegate = null;
+			}
+		}
+
+		void remove(ApplicationContext applicationContext) {
+			synchronized (this) {
+				this.publishers.remove(applicationContext);
+				this.delegate = null;
+			}
+		}
+
+		private ContextStorage getDelegate(ContextStorage parent) {
+			ContextStorage delegate = this.delegate;
+			if (delegate == null) {
+				synchronized (this) {
+					delegate = parent;
+					for (List<EventPublishingContextWrapper> publishers : this.publishers.values()) {
+						for (EventPublishingContextWrapper publisher : publishers) {
+							delegate = publisher.apply(delegate);
+						}
+					}
+				}
+			}
+			return delegate;
+		}
+
+		/**
+		 * The wrapped {@link ContextStorage} that delegates to the
+		 * {@link EventPublisherBeansContextWrapper}.
+		 */
+		class EventPublisherBeansContextStorage implements ContextStorage {
+
+			private final ContextStorage parent;
+
+			EventPublisherBeansContextStorage(ContextStorage wrapped) {
+				this.parent = wrapped;
+			}
+
+			@Override
+			public Scope attach(Context toAttach) {
+				return getDelegate(this.parent).attach(toAttach);
+			}
+
+			@Override
+			public Context current() {
+				return getDelegate(this.parent).current();
+			}
+
+			@Override
+			public Context root() {
+				return getDelegate(this.parent).root();
+			}
+
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/resources/META-INF/spring.factories

@@ -10,3 +10,7 @@ org.springframework.boot.actuate.autoconfigure.metrics.ValidationFailureAnalyzer
 # Environment Post Processors
 org.springframework.boot.env.EnvironmentPostProcessor=\
 org.springframework.boot.actuate.autoconfigure.tracing.LogCorrelationEnvironmentPostProcessor
+
+# Application Listeners
+org.springframework.context.ApplicationListener=\
+org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryEventPublisherApplicationListener

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

@@ -31,10 +31,13 @@ import org.junit.jupiter.params.provider.EnumSource;
 import org.slf4j.MDC;
 
 import org.springframework.boot.actuate.autoconfigure.opentelemetry.OpenTelemetryAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryEventPublisherApplicationListener.EventPublisherBeansContextWrapper;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.testsupport.classpath.ForkedClassPath;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -55,6 +58,7 @@ class BaggagePropagationIntegrationTests {
 	@BeforeEach
 	@AfterEach
 	void setup() {
+		EventPublisherBeansContextWrapper.addWrapperIfNecessary();
 		MDC.clear();
 	}
 
@@ -155,6 +159,7 @@ class BaggagePropagationIntegrationTests {
 	enum AutoConfig implements Supplier<ApplicationContextRunner> {
 
 		BRAVE_DEFAULT {
+
 			@Override
 			public ApplicationContextRunner get() {
 				return new ApplicationContextRunner()
@@ -162,20 +167,24 @@ class BaggagePropagationIntegrationTests {
 					.withPropertyValues("management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		OTEL_DEFAULT {
+
 			@Override
 			public ApplicationContextRunner get() {
-				return new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(
-						OpenTelemetryAutoConfiguration.class,
-						org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
+				return new ApplicationContextRunner().withInitializer(new OtelApplicationContextInitializer())
+					.withConfiguration(AutoConfigurations.of(OpenTelemetryAutoConfiguration.class,
+							org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
 					.withPropertyValues("management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		BRAVE_W3C {
+
 			@Override
 			public ApplicationContextRunner get() {
 				return new ApplicationContextRunner()
@@ -184,21 +193,25 @@ class BaggagePropagationIntegrationTests {
 							"management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		OTEL_W3C {
+
 			@Override
 			public ApplicationContextRunner get() {
-				return new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(
-						OpenTelemetryAutoConfiguration.class,
-						org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
+				return new ApplicationContextRunner().withInitializer(new OtelApplicationContextInitializer())
+					.withConfiguration(AutoConfigurations.of(OpenTelemetryAutoConfiguration.class,
+							org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
 					.withPropertyValues("management.tracing.propagation.type=W3C",
 							"management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		BRAVE_B3 {
+
 			@Override
 			public ApplicationContextRunner get() {
 				return new ApplicationContextRunner()
@@ -207,9 +220,11 @@ class BaggagePropagationIntegrationTests {
 							"management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		BRAVE_B3_MULTI {
+
 			@Override
 			public ApplicationContextRunner get() {
 				return new ApplicationContextRunner()
@@ -218,33 +233,39 @@ class BaggagePropagationIntegrationTests {
 							"management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		OTEL_B3 {
+
 			@Override
 			public ApplicationContextRunner get() {
-				return new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(
-						OpenTelemetryAutoConfiguration.class,
-						org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
+				return new ApplicationContextRunner().withInitializer(new OtelApplicationContextInitializer())
+					.withConfiguration(AutoConfigurations.of(OpenTelemetryAutoConfiguration.class,
+							org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
 					.withPropertyValues("management.tracing.propagation.type=B3",
 							"management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		OTEL_B3_MULTI {
+
 			@Override
 			public ApplicationContextRunner get() {
-				return new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(
-						OpenTelemetryAutoConfiguration.class,
-						org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
+				return new ApplicationContextRunner().withInitializer(new OtelApplicationContextInitializer())
+					.withConfiguration(AutoConfigurations.of(OpenTelemetryAutoConfiguration.class,
+							org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryAutoConfiguration.class))
 					.withPropertyValues("management.tracing.propagation.type=B3_MULTI",
 							"management.tracing.baggage.remote-fields=x-vcap-request-id,country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		},
 
 		BRAVE_LOCAL_FIELDS {
+
 			@Override
 			public ApplicationContextRunner get() {
 				return new ApplicationContextRunner()
@@ -252,6 +273,7 @@ class BaggagePropagationIntegrationTests {
 					.withPropertyValues("management.tracing.baggage.local-fields=country-code,bp",
 							"management.tracing.baggage.correlation.fields=country-code,bp");
 			}
+
 		};
 
 		boolean isOtel() {
@@ -264,4 +286,14 @@ class BaggagePropagationIntegrationTests {
 
 	}
 
+	static class OtelApplicationContextInitializer
+			implements ApplicationContextInitializer<ConfigurableApplicationContext> {
+
+		@Override
+		public void initialize(ConfigurableApplicationContext applicationContext) {
+			applicationContext.addApplicationListener(new OpenTelemetryEventPublisherApplicationListener());
+		}
+
+	}
+
 }

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

@@ -26,6 +26,8 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
 import io.micrometer.tracing.SpanCustomizer;
+import io.micrometer.tracing.Tracer.SpanInScope;
+import io.micrometer.tracing.otel.bridge.EventListener;
 import io.micrometer.tracing.otel.bridge.OtelCurrentTraceContext;
 import io.micrometer.tracing.otel.bridge.OtelPropagator;
 import io.micrometer.tracing.otel.bridge.OtelSpanCustomizer;
@@ -37,6 +39,7 @@ import io.micrometer.tracing.otel.propagation.BaggageTextMapPropagator;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.MeterProvider;
+import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.Tracer;
 import io.opentelemetry.api.trace.propagation.W3CTraceContextPropagator;
 import io.opentelemetry.context.propagation.ContextPropagators;
@@ -52,15 +55,18 @@ import io.opentelemetry.sdk.trace.export.SpanExporter;
 import io.opentelemetry.sdk.trace.samplers.Sampler;
 import io.opentelemetry.semconv.ResourceAttributes;
 import org.assertj.core.api.InstanceOfAssertFactories;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.Mockito;
 
 import org.springframework.boot.actuate.autoconfigure.observation.ObservationAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.tracing.OpenTelemetryEventPublisherApplicationListener.EventPublisherBeansContextWrapper;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.annotation.Order;
@@ -86,6 +92,11 @@ class OpenTelemetryAutoConfigurationTests {
 				org.springframework.boot.actuate.autoconfigure.opentelemetry.OpenTelemetryAutoConfiguration.class,
 				OpenTelemetryAutoConfiguration.class));
 
+	@BeforeAll
+	static void addWrapper() {
+		EventPublisherBeansContextWrapper.addWrapperIfNecessary();
+	}
+
 	@Test
 	void shouldSupplyBeans() {
 		this.contextRunner.run((context) -> {
@@ -316,6 +327,28 @@ class OpenTelemetryAutoConfigurationTests {
 		});
 	}
 
+	@Test // gh-41439
+	void shouldPublishEventsWhenContextStorageIsInitializedEarly() {
+		this.contextRunner.withInitializer(this::initializeOpenTelemetry)
+			.withUserConfiguration(OtelEventListener.class)
+			.run((context) -> {
+				OtelEventListener listener = context.getBean(OtelEventListener.class);
+				io.micrometer.tracing.Tracer micrometerTracer = context.getBean(io.micrometer.tracing.Tracer.class);
+				io.micrometer.tracing.Span span = micrometerTracer.nextSpan().name("test");
+				try (SpanInScope scoped = micrometerTracer.withSpan(span.start())) {
+					assertThat(listener.events).isNotEmpty();
+				}
+				finally {
+					span.end();
+				}
+			});
+	}
+
+	private void initializeOpenTelemetry(ConfigurableApplicationContext context) {
+		context.addApplicationListener(new OpenTelemetryEventPublisherApplicationListener());
+		Span.current();
+	}
+
 	private List<TextMapPropagator> getInjectors(TextMapPropagator propagator) {
 		assertThat(propagator).as("propagator").isNotNull();
 		if (propagator instanceof CompositeTextMapPropagator compositePropagator) {
@@ -531,4 +564,15 @@ class OpenTelemetryAutoConfigurationTests {
 
 	}
 
+	static class OtelEventListener implements EventListener {
+
+		private final List<Object> events = new ArrayList<>();
+
+		@Override
+		public void onEvent(Object event) {
+			this.events.add(event);
+		}
+
+	}
+
 }