feat: Add gRPC config and endpoint for overlapping

Dockerfile

@@ -8,5 +8,6 @@ RUN addgroup -S spring && adduser -S spring -G spring
 USER spring:spring
 
 EXPOSE 8080
+EXPOSE 9090
 
 ENTRYPOINT ["java", "-jar", "app.jar"]

build.gradle.kts

@@ -1,8 +1,11 @@
+import com.google.protobuf.gradle.*
+
 plugins {
 	java
 	jacoco
 	id("org.springframework.boot") version "4.0.1"
 	id("io.spring.dependency-management") version "1.1.7"
+	id("com.google.protobuf") version "0.9.4"
 }
 
 group = "com.devoops"
@@ -19,6 +22,8 @@ repositories {
 	mavenCentral()
 }
 
+val grpcVersion = "1.68.0"
+
 dependencies {
 	// Web and Core
 	implementation("org.springframework.boot:spring-boot-starter-webmvc")
@@ -40,6 +45,13 @@ dependencies {
 	annotationProcessor("org.mapstruct:mapstruct-processor:1.6.3")
 	annotationProcessor("org.projectlombok:lombok-mapstruct-binding:0.2.0")
 
+	// gRPC Server
+	implementation("net.devh:grpc-server-spring-boot-starter:3.1.0.RELEASE")
+	implementation("io.grpc:grpc-protobuf:$grpcVersion")
+	implementation("io.grpc:grpc-stub:$grpcVersion")
+	implementation("io.grpc:grpc-netty-shaded:$grpcVersion")
+	compileOnly("javax.annotation:javax.annotation-api:1.3.2")
+
 	// Prometheus
 	implementation("io.micrometer:micrometer-registry-prometheus")
 
@@ -64,6 +76,24 @@ dependencies {
 	testRuntimeOnly("org.junit.platform:junit-platform-launcher")
 }
 
+protobuf {
+	protoc {
+		artifact = "com.google.protobuf:protoc:3.25.5"
+	}
+	plugins {
+		id("grpc") {
+			artifact = "io.grpc:protoc-gen-grpc-java:$grpcVersion"
+		}
+	}
+	generateProtoTasks {
+		all().forEach { task ->
+			task.plugins {
+				id("grpc")
+			}
+		}
+	}
+}
+
 tasks.withType<Test> {
 	useJUnitPlatform()
 	finalizedBy(tasks.jacocoTestReport)

environment/.local.env

@@ -5,4 +5,5 @@ ZIPKIN_PORT=9411
 POSTGRES_HOST=devoops-postgres
 POSTGRES_PORT=5432
 DB_USERNAME=reservation-service
-DB_PASSWORD=reservation-service-pass
+DB_PASSWORD=reservation-service-pass
+GRPC_PORT=9090

src/main/java/com/devoops/reservation/grpc/ReservationGrpcService.java

@@ -0,0 +1,44 @@
+package com.devoops.reservation.grpc;
+
+import com.devoops.reservation.entity.Reservation;
+import com.devoops.reservation.grpc.proto.CheckReservationsExistRequest;
+import com.devoops.reservation.grpc.proto.CheckReservationsExistResponse;
+import com.devoops.reservation.grpc.proto.ReservationInternalServiceGrpc;
+import com.devoops.reservation.repository.ReservationRepository;
+import io.grpc.stub.StreamObserver;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import net.devh.boot.grpc.server.service.GrpcService;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.UUID;
+
+@GrpcService
+@RequiredArgsConstructor
+@Slf4j
+public class ReservationGrpcService extends ReservationInternalServiceGrpc.ReservationInternalServiceImplBase {
+
+    private final ReservationRepository reservationRepository;
+
+    @Override
+    public void checkReservationsExist(CheckReservationsExistRequest request,
+                                       StreamObserver<CheckReservationsExistResponse> responseObserver) {
+        UUID accommodationId = UUID.fromString(request.getAccommodationId());
+        LocalDate startDate = LocalDate.parse(request.getStartDate());
+        LocalDate endDate = LocalDate.parse(request.getEndDate());
+
+        log.debug("gRPC: Checking reservations for accommodation {} between {} and {}",
+                accommodationId, startDate, endDate);
+
+        List<Reservation> overlapping = reservationRepository.findOverlappingApproved(
+                accommodationId, startDate, endDate);
+
+        CheckReservationsExistResponse response = CheckReservationsExistResponse.newBuilder()
+                .setHasReservations(!overlapping.isEmpty())
+                .build();
+
+        responseObserver.onNext(response);
+        responseObserver.onCompleted();
+    }
+}

src/main/proto/reservation_internal.proto

@@ -0,0 +1,20 @@
+syntax = "proto3";
+
+package reservation;
+
+option java_multiple_files = true;
+option java_package = "com.devoops.reservation.grpc.proto";
+
+service ReservationInternalService {
+  rpc CheckReservationsExist(CheckReservationsExistRequest) returns (CheckReservationsExistResponse);
+}
+
+message CheckReservationsExistRequest {
+  string accommodation_id = 1;
+  string start_date = 2;
+  string end_date = 3;
+}
+
+message CheckReservationsExistResponse {
+  bool has_reservations = 1;
+}

src/main/resources/application.properties

@@ -29,3 +29,6 @@ management.tracing.export.zipkin.endpoint=http://${ZIPKIN_HOST:zipkin}:${ZIPKIN_
 management.endpoints.web.exposure.include=health,info,prometheus
 management.endpoint.health.show-details=always
 management.prometheus.metrics.export.enabled=true
+
+# gRPC Server
+grpc.server.port=${GRPC_PORT:9090}