#1: Autoconfigure metric registry support

- keep only AutoConfiguration

Signed-off-by: Sunny <hmtang@gmail.com>
[resolves #1]

Author: hmtang

samples/grpc-server/src/test/java/org/springframework/grpc/sample/GrpcServerApplicationTests.java

@@ -1,9 +1,7 @@
 package org.springframework.grpc.sample;
 
-import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import io.micrometer.core.instrument.MeterRegistry;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.junit.jupiter.api.Test;
@@ -32,9 +30,6 @@ public static void main(String[] args) {
 	@Autowired
 	private SimpleGrpc.SimpleBlockingStub stub;
 
-	@Autowired
-	private MeterRegistry meterRegistry;
-
 	@Test
 	@DirtiesContext
 	void contextLoads() {
@@ -48,18 +43,6 @@ void serverResponds() {
 		assertEquals("Hello ==> Alien", response.getMessage());
 	}
 
-	@Test
-	@DirtiesContext
-	void verifyMetrics() {
-		log.info("Verify stats are collected");
-		stub.sayHello(HelloRequest.newBuilder().setName("Alien").build());
-		assertThat(meterRegistry.get("grpc.server.requests.received").counter().count()).isEqualTo(1);
-		assertThat(meterRegistry.get("grpc.server.responses.sent").counter().count()).isEqualTo(1);
-		stub.sayHello(HelloRequest.newBuilder().setName("Jamie").build());
-		assertThat(meterRegistry.get("grpc.server.requests.received").counter().count()).isEqualTo(2);
-		assertThat(meterRegistry.get("grpc.server.responses.sent").counter().count()).isEqualTo(2);
-	}
-
 	@TestConfiguration
 	static class ExtraConfiguration {
 

spring-grpc-core/pom.xml

@@ -71,10 +71,6 @@
 			<groupId>io.micrometer</groupId>
 			<artifactId>micrometer-core</artifactId>
 		</dependency>
-		<dependency>
-			<groupId>io.micrometer</groupId>
-			<artifactId>micrometer-registry-prometheus</artifactId>
-		</dependency>
 
 		<dependency>
 			<groupId>org.junit.jupiter</groupId>

spring-grpc-core/src/main/java/org/springframework/grpc/server/DefaultGrpcServerFactory.java

@@ -23,11 +23,16 @@
 
 import com.google.common.collect.Lists;
 
-import io.grpc.*;
+import io.grpc.Grpc;
+import io.grpc.InsecureServerCredentials;
+import io.grpc.Server;
+import io.grpc.ServerBuilder;
+import io.grpc.ServerCredentials;
+import io.grpc.ServerProvider;
+import io.grpc.ServerServiceDefinition;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.grpc.internal.GrpcUtils;
 
 /**
@@ -51,9 +56,6 @@ public class DefaultGrpcServerFactory<T extends ServerBuilder<T>> implements Grp
 
 	private final List<ServerBuilderCustomizer<T>> serverBuilderCustomizers;
 
-	@Autowired
-	private List<ServerInterceptor> serverInterceptors;
-
 	public DefaultGrpcServerFactory(String address, List<ServerBuilderCustomizer<T>> serverBuilderCustomizers) {
 		this.address = address;
 		this.serverBuilderCustomizers = Objects.requireNonNull(serverBuilderCustomizers, "serverBuilderCustomizers");
@@ -81,11 +83,7 @@ public void addService(ServerServiceDefinition service) {
 	 */
 	@SuppressWarnings("unchecked")
 	protected T newServerBuilder() {
-		var builder = Grpc.newServerBuilderForPort(port(), credentials());
-		for (ServerInterceptor interceptor : serverInterceptors) {
-			builder.intercept(interceptor);
-		}
-		return (T) builder;
+		return (T) Grpc.newServerBuilderForPort(port(), credentials());
 	}
 
 	/**

spring-grpc-dependencies/pom.xml

@@ -115,13 +115,10 @@
 			</dependency>
 			<dependency>
 				<groupId>io.micrometer</groupId>
-				<artifactId>micrometer-core</artifactId>
-				<version>${micrometer.version}</version>
-			</dependency>
-			<dependency>
-				<groupId>io.micrometer</groupId>
-				<artifactId>micrometer-registry-prometheus</artifactId>
+				<artifactId>micrometer-bom</artifactId>
 				<version>${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/GrpcServerAutoConfiguration.java

@@ -15,10 +15,6 @@
  */
 package org.springframework.grpc.autoconfigure.server;
 
-import io.grpc.ServerInterceptor;
-import io.micrometer.core.instrument.MeterRegistry;
-import io.micrometer.core.instrument.binder.grpc.MetricCollectingServerInterceptor;
-import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
@@ -73,15 +69,4 @@ ServerBuilderCustomizers serverBuilderCustomizers(ObjectProvider<ServerBuilderCu
 		return new ServerBuilderCustomizers(customizers.orderedStream().toList());
 	}
 
-	@ConditionalOnMissingBean
-	@Bean
-	public MeterRegistry meterRegistry() {
-		return new SimpleMeterRegistry();
-	}
-
-	@Bean
-	public ServerInterceptor metricCollectingServerInterceptor(MeterRegistry meterRegistry) {
-		return new MetricCollectingServerInterceptor(meterRegistry);
-	}
-
 }

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

@@ -0,0 +1,27 @@
+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);
+    }
+}