gRPC 통신 간에 서킷브레이커 적용

buildSrc/src/main/kotlin/Dependencies.kt

@@ -58,4 +58,10 @@ object Dependencies {
 
     // Spring Cloud Config
     const val SPRING_CLOUD_CONFIG = "org.springframework.cloud:spring-cloud-starter-config"
+
+    //Resilience4j
+    const val RESILIENCE4J_CIRCUITBREAKER = "io.github.resilience4j:resilience4j-circuitbreaker:${DependencyVersion.RESILIENCE4J}"
+    const val RESILIENCE4J_RETRY = "io.github.resilience4j:resilience4j-retry:${DependencyVersion.RESILIENCE4J}"
+    const val RESILIENCE4J_SPRING_BOOT = "io.github.resilience4j:resilience4j-spring-boot3:${DependencyVersion.RESILIENCE4J}"
+    const val RESILIENCE4J_KOTLIN = "io.github.resilience4j:resilience4j-kotlin:${DependencyVersion.RESILIENCE4J}"
 }

buildSrc/src/main/kotlin/DependencyVersion.kt

@@ -24,4 +24,7 @@ object DependencyVersion {
     const val OPEN_FEIGN_VERSION = "3.1.4"
 
     const val SPRING_CLOUD_CONFIG_VERSION = "2023.0.3"
+
+    //Resilience4j
+    const val RESILIENCE4J = "2.0.2"
 }

casper-feed/build.gradle.kts

@@ -97,6 +97,12 @@ dependencies {
 
     // Cloud Config
     implementation(Dependencies.SPRING_CLOUD_CONFIG)
+
+    // Resilience4j
+    implementation(Dependencies.RESILIENCE4J_CIRCUITBREAKER)
+    implementation(Dependencies.RESILIENCE4J_RETRY)
+    implementation(Dependencies.RESILIENCE4J_SPRING_BOOT)
+    implementation(Dependencies.RESILIENCE4J_KOTLIN)
 }
 
 protobuf {

casper-feed/src/main/kotlin/hs/kr/entrydsm/feed/global/config/ResilienceConfig.kt

@@ -0,0 +1,41 @@
+package hs.kr.entrydsm.feed.global.config
+
+import io.github.resilience4j.circuitbreaker.CircuitBreaker
+import io.github.resilience4j.circuitbreaker.CircuitBreakerRegistry
+import io.github.resilience4j.retry.Retry
+import io.github.resilience4j.retry.RetryRegistry
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+
+/**
+ * Resilience4j 관련 설정을 담당하는 클래스입니다.
+ *
+ * @property circuitBreakerRegistry CircuitBreaker 인스턴스를 생성하고 관리합니다.
+ * @property retryRegistry Retry 인스턴스를 생성하고 관리합니다.
+ */
+@Configuration
+class ResilienceConfig(
+    private val circuitBreakerRegistry: CircuitBreakerRegistry,
+    private val retryRegistry: RetryRegistry
+) {
+
+    /**
+     * user-grpc 서킷 브레이커를 생성합니다.
+     *
+     * @return user-grpc 이름의 CircuitBreaker 인스턴스
+     */
+    @Bean
+    fun userGrpcCircuitBreaker(): CircuitBreaker {
+        return circuitBreakerRegistry.circuitBreaker("user-grpc")
+    }
+
+    /**
+     * user-grpc 리트라이를 생성합니다.
+     *
+     * @return user-grpc 이름의 Retry 인스턴스
+     */
+    @Bean
+    fun userGrpcRetry(): Retry {
+        return retryRegistry.retry("user-grpc")
+    }
+}

casper-feed/src/main/kotlin/hs/kr/entrydsm/feed/global/extension/ResilienceGrpcExtensions.kt

@@ -0,0 +1,37 @@
+package hs.kr.entrydsm.feed.global.extension
+
+import io.github.resilience4j.circuitbreaker.CircuitBreaker
+import io.github.resilience4j.kotlin.circuitbreaker.executeSuspendFunction
+import io.github.resilience4j.kotlin.retry.executeSuspendFunction
+import io.github.resilience4j.retry.Retry
+import kotlinx.coroutines.CancellationException
+import org.slf4j.LoggerFactory
+
+private val log = LoggerFactory.getLogger("ResilienceGrpcExtensions")
+
+/**
+ * gRPC 호출에 대해 Retry와 CircuitBreaker를 적용합니다.
+ *
+ * @param T gRPC 함수의 반환 타입
+ * @param retry 적용할 Retry 인스턴스
+ * @param circuitBreaker 적용할 CircuitBreaker 인스턴스
+ * @param fallback gRPC 호출 실패 시 실행할 함수
+ * @param block 실행할 gRPC 함수
+ * @return gRPC 함수의 실행 결과를 반환하거나, 실패 시 fallback 함수의 결과를 반환
+ */
+suspend fun <T> executeGrpcCallWithResilience(
+    retry: Retry,
+    circuitBreaker: CircuitBreaker,
+    fallback: suspend () -> T,
+    block: suspend () -> T
+): T =
+    try {
+        retry.executeSuspendFunction {
+            circuitBreaker.executeSuspendFunction(block)
+        }
+    } catch (ce: CancellationException) {
+        throw ce
+    } catch (e: Exception) {
+        log.warn("gRPC 호출 실패, fallback 실행: {}", e.toString())
+        fallback()
+    }

casper-feed/src/main/kotlin/hs/kr/entrydsm/feed/global/utils/admin/AdminUtils.kt

@@ -1,8 +1,8 @@
 package hs.kr.entrydsm.feed.global.utils.admin
 
 import hs.kr.entrydsm.feed.global.exception.InvalidTokenException
-import hs.kr.entrydsm.feed.infrastructure.grpc.client.AdminGrpcClient
-import hs.kr.entrydsm.feed.infrastructure.grpc.client.dto.response.InternalAdminResponse
+import hs.kr.entrydsm.feed.infrastructure.grpc.user.client.UserGrpcClient
+import hs.kr.entrydsm.feed.infrastructure.grpc.user.client.dto.response.InternalAdminResponse
 import org.springframework.security.core.context.SecurityContextHolder
 import org.springframework.stereotype.Component
 import java.util.*
@@ -12,11 +12,11 @@ import java.util.*
  * Spring Security의 SecurityContext를 사용하여 현재 인증된 관리자 정보를 조회하고,
  * gRPC를 통해 관리자 서비스에서 추가 정보를 조회합니다.
  *
- * @property adminGrpcClient 관리자 정보 조회를 위한 gRPC 클라이언트
+ * @property userGrpcClient 관리자 정보 조회를 위한 gRPC 클라이언트
  */
 @Component
 class AdminUtils(
-    private val adminGrpcClient: AdminGrpcClient
+    private val userGrpcClient: UserGrpcClient
 ) {
 
     /**
@@ -28,7 +28,7 @@ class AdminUtils(
      * @throws hs.kr.entrydsm.feed.global.exception.InvalidTokenException 인증 토큰이 유효하지 않은 경우
      * @throws io.grpc.StatusRuntimeException gRPC 통신 중 오류가 발생한 경우
      */
-    suspend fun getCurrentAdmin(): InternalAdminResponse = adminGrpcClient.getAdminInfoByAdminId(getCurrentAdminId())
+    suspend fun getCurrentAdmin(): InternalAdminResponse = userGrpcClient.getAdminInfoByAdminId(getCurrentAdminId())
 
     /**
      * 현재 인증된 관리자의 고유 식별자(UUID)를 조회합니다.

casper-feed/src/main/kotlin/hs/kr/entrydsm/feed/infrastructure/grpc/user/client/UserGrpcClient.kt

@@ -0,0 +1,70 @@
+package hs.kr.entrydsm.feed.infrastructure.grpc.user.client
+
+import hs.kr.entrydsm.casper.admin.proto.AdminServiceGrpc
+import hs.kr.entrydsm.casper.admin.proto.AdminServiceProto
+import hs.kr.entrydsm.feed.global.extension.executeGrpcCallWithResilience
+import hs.kr.entrydsm.feed.infrastructure.grpc.user.client.dto.response.InternalAdminResponse
+import io.github.resilience4j.circuitbreaker.CircuitBreaker
+import io.github.resilience4j.retry.Retry
+import io.grpc.Channel
+import io.grpc.stub.StreamObserver
+import kotlinx.coroutines.suspendCancellableCoroutine
+import net.devh.boot.grpc.client.inject.GrpcClient
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.stereotype.Component
+import java.util.UUID
+import kotlin.coroutines.resume
+import kotlin.coroutines.resumeWithException
+
+/**
+ * 관리자 서비스와의 gRPC 통신을 담당하는 클라이언트 클래스입니다.
+ *
+ * @property channel gRPC 통신을 위한 채널 (user-service로 자동 주입됨)
+ */
+@Component
+class UserGrpcClient(
+    @Qualifier("userGrpcRetry") private val retry: Retry,
+    @Qualifier("userGrpcCircuitBreaker") private val circuitBreaker: CircuitBreaker
+) {
+
+    @GrpcClient("user-service")
+    lateinit var channel: Channel
+
+    /**
+     * 관리자 ID를 기반으로 관리자 정보를 비동기적으로 조회합니다.
+     * gRPC 비동기 스트리밍을 사용하여 관리자 서비스로부터 정보를 가져옵니다.
+     *
+     * @param adminId 조회할 관리자의 고유 식별자(UUID)
+     * @return 조회된 관리자 정보를 담은 [InternalAdminResponse] 객체
+     * @throws io.grpc.StatusRuntimeException gRPC 서버에서 오류가 발생한 경우
+     * @throws java.util.concurrent.CancellationException 코루틴이 취소된 경우
+     */
+    suspend fun getAdminInfoByAdminId(adminId: UUID): InternalAdminResponse {
+
+        return executeGrpcCallWithResilience(
+            retry = retry,
+            circuitBreaker = circuitBreaker,
+            fallback = { InternalAdminResponse(adminId) }
+        ) {
+            val adminStub = AdminServiceGrpc.newStub(channel)
+
+            val request = AdminServiceProto.GetAdminIdRequest.newBuilder()
+                .setAdminId(adminId.toString())
+                .build()
+
+            val response = suspendCancellableCoroutine { continuation ->
+                adminStub.getAdminByUUID(request, object : StreamObserver<AdminServiceProto.GetAdminIdResponse> {
+                    override fun onNext(value: AdminServiceProto.GetAdminIdResponse) {
+                        continuation.resume(value)
+                    }
+                    override fun onError(t: Throwable) {
+                        continuation.resumeWithException(t)
+                    }
+                    override fun onCompleted() {}
+                })
+            }
+
+            InternalAdminResponse(id = UUID.fromString(response.adminId))
+        }
+    }
+}

casper-feed/src/main/kotlin/hs/kr/entrydsm/feed/infrastructure/grpc/client/dto/response/InternalAdminResponse.kt → casper-feed/src/main/kotlin/hs/kr/entrydsm/feed/infrastructure/grpc/user/client/dto/response/InternalAdminResponse.kt

@@ -1,4 +1,4 @@
-package hs.kr.entrydsm.feed.infrastructure.grpc.client.dto.response
+package hs.kr.entrydsm.feed.infrastructure.grpc.user.client.dto.response
 
 import java.util.UUID