Temporarily remove auto-config for Reactor context propagation

See gh-34201

spring-boot-project/spring-boot-autoconfigure/build.gradle

@@ -221,7 +221,6 @@ dependencies {
 	testImplementation("com.querydsl:querydsl-core")
 	testImplementation("com.squareup.okhttp3:mockwebserver")
 	testImplementation("com.sun.xml.messaging.saaj:saaj-impl")
-	testImplementation("io.micrometer:context-propagation")
 	testImplementation("io.projectreactor:reactor-test")
 	testImplementation("io.r2dbc:r2dbc-h2")
 	testImplementation("jakarta.json:jakarta.json-api")

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/reactor/ReactorAutoConfiguration.java

@@ -1,43 +0,0 @@
-/*
- * 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.
- * 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.autoconfigure.reactor;
-
-import reactor.core.publisher.Hooks;
-
-import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
-import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.context.annotation.Configuration;
-
-/**
- * {@link EnableAutoConfiguration Auto-configuration} for Reactor.
- *
- * @author Brian Clozel
- * @since 3.0.2
- */
-@Configuration(proxyBeanMethods = false)
-@ConditionalOnClass(Hooks.class)
-@EnableConfigurationProperties(ReactorProperties.class)
-public class ReactorAutoConfiguration {
-
-	public ReactorAutoConfiguration(ReactorProperties properties) {
-		if (properties.getContextPropagation() == ReactorProperties.ContextPropagationMode.AUTO) {
-			Hooks.enableAutomaticContextPropagation();
-		}
-	}
-
-}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/reactor/ReactorProperties.java

@@ -1,57 +0,0 @@
-/*
- * 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.
- * 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.autoconfigure.reactor;
-
-import org.springframework.boot.context.properties.ConfigurationProperties;
-
-/**
- * Configuration properties for Reactor.
- *
- * @author Brian Clozel
- * @since 3.0.3
- */
-@ConfigurationProperties(prefix = "spring.reactor")
-public class ReactorProperties {
-
-	/**
-	 * Context Propagation support mode for Reactor operators.
-	 */
-	private ContextPropagationMode contextPropagation = ContextPropagationMode.AUTO;
-
-	public ContextPropagationMode getContextPropagation() {
-		return this.contextPropagation;
-	}
-
-	public void setContextPropagation(ContextPropagationMode contextPropagation) {
-		this.contextPropagation = contextPropagation;
-	}
-
-	public enum ContextPropagationMode {
-
-		/**
-		 * Context Propagation is applied to all Reactor operators.
-		 */
-		AUTO,
-
-		/**
-		 * Context Propagation is only applied to "tap" and "handle" Reactor operators.
-		 */
-		LIMITED
-
-	}
-
-}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/reactor/package-info.java

@@ -1,20 +0,0 @@
-/*
- * 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.
- * 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.
- */
-
-/**
- * Auto-configuration for Reactor.
- */
-package org.springframework.boot.autoconfigure.reactor;

spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -2176,10 +2176,6 @@
         "level": "error"
       }
     },
-    {
-      "name": "spring.reactor.context-propagation",
-      "defaultValue": "auto"
-    },
     {
       "name": "spring.reactor.stacktrace-mode.enabled",
       "description": "Whether Reactor should collect stacktrace information at runtime.",

spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -93,7 +93,6 @@ org.springframework.boot.autoconfigure.neo4j.Neo4jAutoConfiguration
 org.springframework.boot.autoconfigure.netty.NettyAutoConfiguration
 org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration
 org.springframework.boot.autoconfigure.quartz.QuartzAutoConfiguration
-org.springframework.boot.autoconfigure.reactor.ReactorAutoConfiguration
 org.springframework.boot.autoconfigure.r2dbc.R2dbcAutoConfiguration
 org.springframework.boot.autoconfigure.r2dbc.R2dbcTransactionManagerAutoConfiguration
 org.springframework.boot.autoconfigure.rsocket.RSocketMessagingAutoConfiguration

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/reactor/ReactorAutoConfigurationTests.java

@@ -1,64 +0,0 @@
-/*
- * 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.
- * 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.autoconfigure.reactor;
-
-import java.util.concurrent.atomic.AtomicReference;
-
-import io.micrometer.context.ContextRegistry;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.Test;
-import reactor.core.publisher.Mono;
-import reactor.util.context.Context;
-
-import org.springframework.boot.autoconfigure.AutoConfigurations;
-import org.springframework.boot.test.context.runner.ApplicationContextRunner;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-/**
- * Tests for {@link ReactorAutoConfiguration}.
- *
- * @author Brian Clozel
- */
-class ReactorAutoConfigurationTests {
-
-	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
-		.withConfiguration(AutoConfigurations.of(ReactorAutoConfiguration.class));
-
-	private static final String THREADLOCAL_KEY = "ReactorAutoConfigurationTests";
-
-	private static final ThreadLocal<String> THREADLOCAL_VALUE = ThreadLocal.withInitial(() -> "failure");
-
-	@BeforeAll
-	static void initializeThreadLocalAccessors() {
-		ContextRegistry globalRegistry = ContextRegistry.getInstance();
-		globalRegistry.registerThreadLocalAccessor(THREADLOCAL_KEY, THREADLOCAL_VALUE);
-	}
-
-	@Test
-	void shouldConfigureAutomaticContextPropagation() {
-		AtomicReference<String> threadLocalValue = new AtomicReference<>();
-		this.contextRunner.run((applicationContext) -> {
-			Mono.just("test")
-				.doOnNext((element) -> threadLocalValue.set(THREADLOCAL_VALUE.get()))
-				.contextWrite(Context.of(THREADLOCAL_KEY, "success"))
-				.block();
-			assertThat(threadLocalValue.get()).isEqualTo("success");
-		});
-	}
-
-}

spring-boot-project/spring-boot-docs/src/docs/asciidoc/actuator/observability.adoc

@@ -21,7 +21,4 @@ For JDBC, the https://github.com/jdbc-observations/datasource-micrometer[Datasou
 Read more about it https://jdbc-observations.github.io/datasource-micrometer/docs/current/docs/html/[in the reference documentation].
 For R2DBC, the https://github.com/spring-projects-experimental/r2dbc-micrometer-spring-boot[Spring Boot Auto Configuration for R2DBC Observation] creates observations for R2DBC query invocations.
 
-Observability support relies on the https://github.com/micrometer-metrics/context-propagation[Context Propagation library] for forwarding the current observation across threads and reactive pipelines.
-`ThreadLocal` values are automatically reinstated in reactive operators, this behavior is controlled with the configprop:spring.reactor.context-propagation[] property.
-
 The next sections will provide more details about logging, metrics and traces.

spring-boot-project/spring-boot-parent/build.gradle

@@ -137,13 +137,6 @@ bom {
 			]
 		}
 	}
-	library("Micrometer Context Propagation", "1.0.2") {
-		group("io.micrometer") {
-			modules = [
-				"context-propagation"
-			]
-		}
-	}
 	library("MockK", "1.10.6") {
 		group("io.mockk") {
 			modules = [