GH-5 - Upgrade observability module to Micrometer.

Re-enable observability module after a migration from Spring Cloud Sleuth to Micrometer. Bind the application of the observability instrumentation to the management.tracing.enabled flag.

pom.xml

@@ -22,7 +22,7 @@
 		<module>spring-modulith-events</module>
 		<module>spring-modulith-test</module>
 		<module>spring-modulith-docs</module>
-		<!--<module>spring-modulith-observability</module>-->
+		<module>spring-modulith-observability</module>
 		<module>spring-modulith-moments</module>
 		<module>spring-modulith-starter-jpa</module>
 		<module>spring-modulith-starter-test</module>
@@ -191,7 +191,6 @@ limitations under the License.
 		<dependency>
 			<groupId>org.projectlombok</groupId>
 			<artifactId>lombok</artifactId>
-			<version>1.18.24</version>
 			<scope>provided</scope>
 		</dependency>
 

spring-modulith-observability/pom.xml

@@ -16,18 +16,6 @@
 		<spring-cloud.version>2021.0.0</spring-cloud.version>
 	</properties>
 
-	<dependencyManagement>
-		<dependencies>
-			<dependency>
-				<groupId>org.springframework.cloud</groupId>
-				<artifactId>spring-cloud-dependencies</artifactId>
-				<version>${spring-cloud.version}</version>
-				<type>pom</type>
-				<scope>import</scope>
-			</dependency>
-		</dependencies>
-	</dependencyManagement>
-
 	<dependencies>
 
 		<dependency>
@@ -42,17 +30,6 @@
 			<optional>true</optional>
 		</dependency>
 
-		<dependency>
-			<groupId>org.springframework.cloud</groupId>
-			<artifactId>spring-cloud-sleuth-api</artifactId>
-		</dependency>
-
-		<dependency>
-			<groupId>org.springframework.cloud</groupId>
-			<artifactId>spring-cloud-sleuth-brave</artifactId>
-			<optional>true</optional>
-		</dependency>
-
 		<dependency>
 			<groupId>org.springframework.data</groupId>
 			<artifactId>spring-data-rest-webmvc</artifactId>
@@ -64,13 +41,45 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
-		
+
 		<dependency>
-			<groupId>org.springframework.cloud</groupId>
-			<artifactId>spring-cloud-starter-sleuth</artifactId>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-observation</artifactId>
+			<optional>true</optional>
+		</dependency>
+
+		<dependency>
+			<groupId>io.zipkin.brave</groupId>
+			<artifactId>brave</artifactId>
+			<optional>true</optional>
+		</dependency>
+
+		<dependency>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-tracing</artifactId>
+			<optional>true</optional>
+		</dependency>
+		
+		<!-- Testing -->
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-actuator-autoconfigure</artifactId>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-tracing-bridge-brave</artifactId>
 			<scope>test</scope>
 		</dependency>
 
 	</dependencies>
 
-</project>
+</project>

spring-modulith-observability/src/main/java/org/springframework/modulith/observability/ModuleEntryInterceptor.java

@@ -15,6 +15,10 @@
  */
 package org.springframework.modulith.observability;
 
+import io.micrometer.tracing.BaggageInScope;
+import io.micrometer.tracing.Span;
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.Tracer.SpanInScope;
 import lombok.AccessLevel;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -24,10 +28,6 @@ import java.util.Map;
 
 import org.aopalliance.intercept.MethodInterceptor;
 import org.aopalliance.intercept.MethodInvocation;
-import org.springframework.cloud.sleuth.BaggageInScope;
-import org.springframework.cloud.sleuth.Span;
-import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer.SpanInScope;
 
 @Slf4j
 @RequiredArgsConstructor(access = AccessLevel.PRIVATE)

spring-modulith-observability/src/main/java/org/springframework/modulith/observability/ModuleEventListener.java

@@ -15,12 +15,12 @@
  */
 package org.springframework.modulith.observability;
 
+import io.micrometer.tracing.Span;
+import io.micrometer.tracing.Tracer;
 import lombok.RequiredArgsConstructor;
 
 import java.util.function.Supplier;
 
-import org.springframework.cloud.sleuth.Span;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.PayloadApplicationEvent;

spring-modulith-observability/src/main/java/org/springframework/modulith/observability/ModuleTracingBeanPostProcessor.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.modulith.observability;
 
+import io.micrometer.tracing.Tracer;
 import lombok.RequiredArgsConstructor;
 
 import java.lang.reflect.Method;
@@ -30,7 +31,6 @@ import org.springframework.aop.support.DefaultPointcutAdvisor;
 import org.springframework.aop.support.StaticMethodMatcher;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanPostProcessor;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.modulith.model.Modules;
 
 /**

spring-modulith-observability/src/main/java/org/springframework/modulith/observability/SpringDataRestModuleTracingBeanPostProcessor.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.modulith.observability;
 
+import io.micrometer.tracing.Tracer;
 import lombok.RequiredArgsConstructor;
 
 import org.aopalliance.aop.Advice;
@@ -24,7 +25,6 @@ import org.springframework.aop.Advisor;
 import org.springframework.aop.support.DefaultPointcutAdvisor;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanPostProcessor;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.data.rest.webmvc.BasePathAwareController;
 import org.springframework.data.rest.webmvc.RootResourceInformation;

spring-modulith-observability/src/main/java/org/springframework/modulith/observability/autoconfigure/ModuleObservabilityAutoConfiguration.java

@@ -22,10 +22,11 @@ import brave.baggage.BaggagePropagationCustomizer;
 import brave.handler.MutableSpan;
 import brave.handler.SpanHandler;
 import brave.propagation.TraceContext;
+import io.micrometer.tracing.Tracer;
 
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
-import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -38,6 +39,7 @@ import org.springframework.modulith.observability.ModulesRuntime;
  * @author Oliver Drotbohm
  */
 @Configuration(proxyBeanMethods = false)
+@ConditionalOnProperty(name = "management.tracing.enabled", havingValue = "true")
 class ModuleObservabilityAutoConfiguration {
 
 	@Bean

spring-modulith-observability/src/main/java/org/springframework/modulith/observability/autoconfigure/SpringDataRestModuleObservabilityAutoConfiguration.java

@@ -15,8 +15,9 @@
  */
 package org.springframework.modulith.observability.autoconfigure;
 
+import io.micrometer.tracing.Tracer;
+
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.rest.webmvc.RepositoryController;

spring-modulith-observability/src/test/java/example/ExampleApplicationIntegrationTests.java

@@ -15,15 +15,26 @@
  */
 package example;
 
+import static org.assertj.core.api.Assertions.*;
+
 import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.actuate.observability.AutoConfigureObservability;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.ApplicationContext;
+import org.springframework.modulith.observability.ModuleEventListener;
 
 /**
  * @author Oliver Drotbohm
  */
 @SpringBootTest
+@AutoConfigureObservability
 class ExampleApplicationIntegrationTests {
 
+	@Autowired ApplicationContext context;
+
 	@Test
-	void bootstrapsSuccessfully() {}
+	void bootstrapsSuccessfully() {
+		assertThat(context.getBean(ModuleEventListener.class)).isNotNull();
+	}
 }

spring-modulith-observability/src/test/resources/application.properties

@@ -1,2 +1,2 @@
-# As long as we're on a Spring Cloud version not officially compatible with Spring Boot 2.7 
-spring.cloud.compatibility-verifier.enabled=false
+management.tracing.enabled=true
+