[FEAT] rabbitmq deadletter 처리

backend/src/main/java/com/twtw/backend/config/rabbitmq/RabbitMQConfig.java

@@ -3,13 +3,8 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.twtw.backend.global.constant.RabbitMQConstant;
 import com.twtw.backend.global.properties.RabbitMQProperties;
-
 import lombok.RequiredArgsConstructor;
-
-import org.springframework.amqp.core.Binding;
-import org.springframework.amqp.core.BindingBuilder;
-import org.springframework.amqp.core.Queue;
-import org.springframework.amqp.core.TopicExchange;
+import org.springframework.amqp.core.*;
 import org.springframework.amqp.rabbit.annotation.EnableRabbit;
 import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
 import org.springframework.amqp.rabbit.connection.ConnectionFactory;
@@ -61,6 +56,23 @@ public Binding notificationBinding() {
                 .with(RabbitMQConstant.NOTIFICATION_ROUTING_KEY.getName());
     }
 
+    @Bean
+    public Queue deadLetterQueue() {
+        return QueueBuilder.durable(RabbitMQConstant.DEAD_LETTER_QUEUE.getName()).build();
+    }
+
+    @Bean
+    public TopicExchange deadLetterExchange() {
+        return new TopicExchange(RabbitMQConstant.DEAD_LETTER_EXCHANGE.getName());
+    }
+
+    @Bean
+    public Binding deadLetterBinding() {
+        return BindingBuilder.bind(deadLetterQueue())
+                .to(deadLetterExchange())
+                .with(RabbitMQConstant.DEAD_LETTER_ROUTING_KEY.getName());
+    }
+
     @Bean
     public ConnectionFactory connectionFactory() {
         CachingConnectionFactory factory = new CachingConnectionFactory();
@@ -94,6 +106,11 @@ public RabbitAdmin rabbitAdmin(final ConnectionFactory connectionFactory) {
         rabbitAdmin.declareQueue(notificationQueue());
         rabbitAdmin.declareExchange(notificationTopicExchange());
         rabbitAdmin.declareBinding(notificationBinding());
+
+        rabbitAdmin.declareQueue(deadLetterQueue());
+        rabbitAdmin.declareExchange(deadLetterExchange());
+        rabbitAdmin.declareBinding(deadLetterBinding());
+
         return rabbitAdmin;
     }
 }

backend/src/main/java/com/twtw/backend/domain/deadletter/DeadLetterConsumer.java

@@ -0,0 +1,32 @@
+package com.twtw.backend.domain.deadletter;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.amqp.rabbit.annotation.RabbitListener;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Slf4j
+@Component
+public class DeadLetterConsumer {
+
+    private final WebClient webClient;
+    private final String slackUrl;
+
+    public DeadLetterConsumer(@Value("${slack.url}") final String slackUrl) {
+        this.webClient = WebClient.create("https://hooks.slack.com/services/");
+        this.slackUrl = slackUrl;
+    }
+
+    @RabbitListener(queues = "deadletter.queue")
+    public void handleDeadLetterMessage(final String message) {
+        log.error("Dead letter received: {}", message);
+        webClient.post()
+                .uri(slackUrl)
+                .bodyValue("{\"text\": \"Dead letter received: " + message + "\"}")
+                .retrieve()
+                .bodyToMono(String.class)
+                .doOnSuccess(s -> log.info("Slack message sent: {}", s))
+                .subscribe();
+    }
+}

backend/src/main/java/com/twtw/backend/global/constant/RabbitMQConstant.java

@@ -12,7 +12,10 @@ public enum RabbitMQConstant {
     LOCATION_ROUTING_KEY_PREFIX("location."),
     NOTIFICATION_QUEUE("notification.queue"),
     NOTIFICATION_EXCHANGE("notification"),
-    NOTIFICATION_ROUTING_KEY("notification");
+    NOTIFICATION_ROUTING_KEY("notification"),
+    DEAD_LETTER_QUEUE("deadletter.queue"),
+    DEAD_LETTER_EXCHANGE("deadletter"),
+    DEAD_LETTER_ROUTING_KEY("deadletter");
 
     private final String name;
 }

backend/src/main/resources/application-prod.yml

@@ -83,3 +83,5 @@ tmap:
   url: ${TMAP_URL}
 firebase:
   location: ${FIREBASE_LOCATION}
+slack:
+  url: ${SLACK_URL}