docker-compose.kafka.yaml

version: "3.9"

services:
  zookeeper:
    image: bitnami/zookeeper:3.9
    container_name: zookeeper
    environment:
      - ALLOW_ANONYMOUS_LOGIN=yes
      - ZOO_HEAP_SIZE=256          # ZK 메모리 축소
    ports:
      - "2181:2181"
    volumes:
      - zookeeper_data:/bitnami/zookeeper
    restart: unless-stopped

  kafka1:
    image: bitnami/kafka:3.6
    container_name: kafka1
    hostname: kafka1
    depends_on:
      - zookeeper
    ports:
      - "9092:9092"    # 외부(호스트) 접속
      # 내부용 19092는 도커 네트워크로만 쓰니 굳이 노출 불필요
    environment:
      - KAFKA_BROKER_ID=1
      - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
      - ALLOW_PLAINTEXT_LISTENER=yes
      - KAFKA_HEAP_OPTS=-Xms256m -Xmx512m   # ★ JVM 힙 축소(저메모리 인스턴스용)
      - KAFKA_CFG_LISTENER_SECURITY_PROTOCOL_MAP=CLIENT:PLAINTEXT,EXTERNAL:PLAINTEXT
      - KAFKA_CFG_LISTENERS=CLIENT://:19092,EXTERNAL://:9092
      - KAFKA_CFG_ADVERTISED_LISTENERS=CLIENT://kafka1:19092,EXTERNAL://localhost:9092
      - KAFKA_INTER_BROKER_LISTENER_NAME=CLIENT
      # 단일 브로커이므로 복제 관련 값은 전부 1
      - KAFKA_CFG_DEFAULT_REPLICATION_FACTOR=1
      - KAFKA_CFG_OFFSETS_TOPIC_REPLICATION_FACTOR=1
      - KAFKA_CFG_TRANSACTION_STATE_LOG_REPLICATION_FACTOR=1
      - KAFKA_CFG_TRANSACTION_STATE_LOG_MIN_ISR=1
      - KAFKA_CFG_MIN_INSYNC_REPLICAS=1
      - KAFKA_CFG_AUTO_CREATE_TOPICS_ENABLE=false
    volumes:
      - kafka1_data:/bitnami/kafka
    restart: unless-stopped

volumes:
  zookeeper_data:
  kafka1_data: