#1: Autoconfigure metric registry support

spring-grpc-core/pom.xml

@@ -67,13 +67,19 @@
 			<artifactId>grpc-stub</artifactId>
 		</dependency>
 
+		<dependency>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-core</artifactId>
+		</dependency>
+
 		<dependency>
 			<groupId>org.junit.jupiter</groupId>
 			<artifactId>junit-jupiter</artifactId>
 			<version>${junit.version}</version>
 			<scope>test</scope>
 		</dependency>
 
+
 	</dependencies>
 
 

spring-grpc-dependencies/pom.xml

@@ -54,6 +54,7 @@
 		<grpc.version>1.63.2</grpc.version>
 		<protobuf-java.version>3.25.5</protobuf-java.version>
 		<google-common-protos.version>2.46.0</google-common-protos.version>
+		<micrometer.version>1.13.6</micrometer.version>
 	</properties>
 
 	<dependencyManagement>
@@ -112,6 +113,13 @@
 				<artifactId>proto-google-common-protos</artifactId>
 				<version>${google-common-protos.version}</version>
 			</dependency>
+			<dependency>
+				<groupId>io.micrometer</groupId>
+				<artifactId>micrometer-bom</artifactId>
+				<version>${micrometer.version}</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
 		</dependencies>
 	</dependencyManagement>
 

spring-grpc-spring-boot-autoconfigure/src/main/java/org/springframework/grpc/autoconfigure/server/GrpcServerMetricAutoConfiguration.java

@@ -0,0 +1,29 @@
+package org.springframework.grpc.autoconfigure.server;
+
+import io.grpc.ServerBuilder;
+import io.grpc.ServerInterceptor;
+import io.micrometer.core.instrument.binder.grpc.ObservationGrpcServerInterceptor;
+import io.micrometer.observation.ObservationRegistry;
+import org.springframework.boot.autoconfigure.AutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.context.annotation.Bean;
+import org.springframework.grpc.server.ServerBuilderCustomizer;
+
+@AutoConfiguration
+@ConditionalOnClass(ObservationGrpcServerInterceptor.class)
+@ConditionalOnBean(ObservationRegistry.class)
+public class GrpcServerMetricAutoConfiguration {
+
+	@Bean
+	public ServerInterceptor observationGrpcServerInterceptor(ObservationRegistry observationRegistry) {
+		return new ObservationGrpcServerInterceptor(observationRegistry);
+	}
+
+	@Bean
+	<T extends ServerBuilder<T>> ServerBuilderCustomizer<T> metricsInterceptor(
+			ServerInterceptor observationGrpcServerInterceptor) {
+		return (serverBuilder) -> serverBuilder.intercept(observationGrpcServerInterceptor);
+	}
+
+}

spring-grpc-spring-boot-autoconfigure/src/test/java/org/springframework/grpc/autoconfigure/server/GrpcServerMetricAutoConfigurationTests.java

@@ -0,0 +1,39 @@
+package org.springframework.grpc.autoconfigure.server;
+
+import io.grpc.ServerBuilder;
+import io.grpc.ServerInterceptor;
+import io.micrometer.core.instrument.binder.grpc.ObservationGrpcServerInterceptor;
+import io.micrometer.observation.ObservationRegistry;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.grpc.server.ServerBuilderCustomizer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class GrpcServerMetricAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withConfiguration(AutoConfigurations.of(GrpcServerMetricAutoConfiguration.class));
+
+	@Test
+	void whenObservationRegistryNotProvided_thenMetricsInterceptorNotConfigured() {
+		this.contextRunner.run(context -> {
+			assertThat(context).doesNotHaveBean(ServerBuilderCustomizer.class);
+		});
+	}
+
+	@Test
+	void whenMetricsInterceptorConfigured_thenServerBuilderCustomizerConfigured() {
+		this.contextRunner.withBean(ObservationRegistry.class, ObservationRegistry::create).run(context -> {
+			assertThat(context).hasSingleBean(ServerBuilderCustomizer.class);
+			assertThat(context).hasSingleBean(ServerInterceptor.class);
+			ServerInterceptor interceptor = context.getBean(ServerInterceptor.class);
+			ServerBuilderCustomizer customizer = context.getBean(ServerBuilderCustomizer.class);
+			ServerBuilder<?> builder = org.mockito.Mockito.mock(ServerBuilder.class);
+			customizer.customize(builder);
+			org.mockito.Mockito.verify(builder, org.mockito.Mockito.times(1)).intercept(interceptor);
+		});
+	}
+
+}