Skip registering all OTLP tracing related beans if tracing is disabled

Before this commit, `OtlpTracingProperties` and `OtlpTracingConnectionDetails` are registered even if tracing is disabled.

Signed-off-by: Yanming Zhou <[email protected]>

Author: quaff

spring-boot-project/spring-boot-tracing/src/main/java/org/springframework/boot/tracing/autoconfigure/otlp/OtlpTracingAutoConfiguration.java

@@ -22,6 +22,7 @@
 import io.opentelemetry.exporter.otlp.trace.OtlpGrpcSpanExporter;
 import io.opentelemetry.sdk.trace.SdkTracerProvider;
 
+import org.springframework.boot.actuate.autoconfigure.tracing.ConditionalOnEnabledTracing;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
@@ -44,10 +45,12 @@
  * @author Jonatan Ivanov
  * @author Moritz Halbritter
  * @author Eddú Meléndez
+ * @author Yanming Zhou
  * @since 4.0.0
  */
 @AutoConfiguration
 @ConditionalOnClass({ OtelTracer.class, SdkTracerProvider.class, OpenTelemetry.class, OtlpHttpSpanExporter.class })
+@ConditionalOnEnabledTracing("otlp")
 @EnableConfigurationProperties(OtlpTracingProperties.class)
 @Import({ OtlpTracingConfigurations.ConnectionDetails.class, OtlpTracingConfigurations.Exporters.class })
 public class OtlpTracingAutoConfiguration {

spring-boot-project/spring-boot-tracing/src/main/java/org/springframework/boot/tracing/autoconfigure/otlp/OtlpTracingConfigurations.java

@@ -38,6 +38,7 @@
  *
  * @author Moritz Halbritter
  * @author Eddú Meléndez
+ * @author Yanming Zhou
  */
 final class OtlpTracingConfigurations {
 
@@ -77,7 +78,6 @@ public String getUrl(Transport transport) {
 	@Configuration(proxyBeanMethods = false)
 	@ConditionalOnMissingBean({ OtlpGrpcSpanExporter.class, OtlpHttpSpanExporter.class })
 	@ConditionalOnBean(OtlpTracingConnectionDetails.class)
-	@ConditionalOnEnabledTracing("otlp")
 	static class Exporters {
 
 		@Bean

spring-boot-project/spring-boot-tracing/src/test/java/org/springframework/boot/tracing/autoconfigure/otlp/OtlpTracingAutoConfigurationTests.java

@@ -44,6 +44,7 @@
  * @author Jonatan Ivanov
  * @author Moritz Halbritter
  * @author Eddú Meléndez
+ * @author Yanming Zhou
  */
 class OtlpTracingAutoConfigurationTests {
 
@@ -71,6 +72,15 @@ void shouldSupplyBeans() {
 				.hasSingleBean(SpanExporter.class));
 	}
 
+	@Test
+	void shouldNotSupplyBeansIfTracingDisabled() {
+		this.tracingDisabledContextRunner
+			.withPropertyValues("management.otlp.tracing.endpoint=http://localhost:4318/v1/traces")
+			.run((context) -> assertThat(context).doesNotHaveBean(OtlpTracingProperties.class)
+				.doesNotHaveBean(OtlpTracingConnectionDetails.class)
+				.doesNotHaveBean(SpanExporter.class));
+	}
+
 	@Test
 	void shouldCustomizeHttpTransportWithProperties() {
 		this.contextRunner