optionally enable server reflection (#83)

* optionally enable server reflection

* add test

* log after registering, not before

Author: jorgheymans

README.adoc

@@ -40,6 +40,14 @@ dependencies {
 A random port can be defined by setting the port to `0`. The actual port being used can then be retrieved from the property `local.grpc.port`, or
 using `@LocalRunningGrpcPort` annotation which will inject the running port (explicitly configured or randomly selected)
 
+* Optionally enable server reflection, see https://github.com/grpc/grpc-java/blob/master/documentation/server-reflection-tutorial.md)
+
+[source,yaml]
+----
+ grpc:
+    enableReflection: true
+----
+
 The starter supports also the `in-process server`, which should be used for testing purposes :
 
 [source,yaml]

grpc-spring-boot-starter-demo/src/main/resources/application.properties

@@ -1,2 +1,3 @@
 security.basic.enabled=false
-management.security.enabled=false
+management.security.enabled=false
+grpc.enableReflection=true

grpc-spring-boot-starter-demo/src/test/java/org/lognet/springboot/grpc/DemoAppTest.java

@@ -8,6 +8,12 @@
 import io.grpc.health.v1.HealthCheckRequest;
 import io.grpc.health.v1.HealthCheckResponse;
 import io.grpc.health.v1.HealthGrpc;
+import io.grpc.protobuf.services.ProtoReflectionService;
+import io.grpc.reflection.v1alpha.ServerReflectionGrpc;
+import io.grpc.reflection.v1alpha.ServerReflectionRequest;
+import io.grpc.reflection.v1alpha.ServerReflectionResponse;
+import io.grpc.reflection.v1alpha.ServiceResponse;
+import io.grpc.stub.StreamObserver;
 import org.junit.Assert;
 import org.junit.Rule;
 import org.junit.Test;
@@ -26,6 +32,8 @@
 import org.springframework.test.context.junit4.SpringRunner;
 
 import java.net.URI;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.ExecutionException;
 
 import static org.hamcrest.CoreMatchers.containsString;
@@ -37,7 +45,7 @@
  * Created by alexf on 28-Jan-16.
  */
 @RunWith(SpringRunner.class)
-@SpringBootTest(classes = {DemoApp.class,TestConfig.class}, webEnvironment = RANDOM_PORT)
+@SpringBootTest(classes = {DemoApp.class,TestConfig.class}, webEnvironment = RANDOM_PORT, properties = "grpc.enableReflection=true")
 public class DemoAppTest extends GrpcServerTestBase{
 
     @Autowired
@@ -94,6 +102,33 @@ public void testDefaultConfigurer(){
                 GRpcServerBuilderConfigurer.class);
     }
 
+    @Test
+    public void testReflection() throws InterruptedException {
+        List<String> discoveredServiceNames = new ArrayList<>();
+        ServerReflectionRequest request = ServerReflectionRequest.newBuilder().setListServices("services").setHost("localhost").build();
+        ServerReflectionGrpc.newStub(channel).serverReflectionInfo(new StreamObserver<ServerReflectionResponse>() {
+            @Override
+            public void onNext(ServerReflectionResponse value) {
+                List<ServiceResponse> serviceList = value.getListServicesResponse().getServiceList();
+                for (ServiceResponse serviceResponse : serviceList) {
+                    discoveredServiceNames.add(serviceResponse.getName());
+                }
+            }
+
+            @Override
+            public void onError(Throwable t) {
+
+            }
+
+            @Override
+            public void onCompleted() {
+
+            }
+        }).onNext(request);
+        Thread.sleep(1000l);
+        assertFalse(discoveredServiceNames.isEmpty());
+    }
+
 
     @Test
     public void testHealthCheck() throws ExecutionException, InterruptedException {

grpc-spring-boot-starter/src/main/java/org/lognet/springboot/grpc/GRpcServerRunner.java

@@ -2,6 +2,7 @@
 
 import io.grpc.*;
 import io.grpc.health.v1.HealthCheckResponse;
+import io.grpc.protobuf.services.ProtoReflectionService;
 import io.grpc.services.HealthStatusManager;
 import lombok.extern.slf4j.Slf4j;
 import org.lognet.springboot.grpc.autoconfigure.GRpcServerProperties;
@@ -80,6 +81,11 @@ public void run(String... args) throws Exception {
 
                 });
 
+        if (gRpcServerProperties.isEnableReflection()) {
+            serverBuilder.addService(ProtoReflectionService.newInstance());
+            log.info("'{}' service has been registered.", ProtoReflectionService.class.getName());
+        }
+
         configurer.configure(serverBuilder);
         server = serverBuilder.build().start();
         applicationContext.publishEvent(new GRpcServerInitializedEvent(server));

grpc-spring-boot-starter/src/main/java/org/lognet/springboot/grpc/autoconfigure/GRpcServerProperties.java

@@ -33,5 +33,11 @@ public class GRpcServerProperties {
      */
     private String inProcessServerName;
 
+    /**
+     * Enables server reflection using <a href="https://github.com/grpc/grpc-java/blob/master/documentation/server-reflection-tutorial.md">ProtoReflectionService</a>.
+     * Available only from gRPC 1.3 or higher.
+     */
+    private boolean enableReflection = false;
+
 
 }