docker-compose.yml

services:
  zookeeper:
    image: confluentinc/cp-zookeeper:7.3.0
    container_name: zookeeper
    networks:
      - pap-platform-network
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000

  kafka:
    image: confluentinc/cp-kafka:7.3.0
    container_name: kafka
    networks:
      - pap-platform-network
    depends_on:
      - zookeeper
    ports:
      # Exposes the Kafka broker on the port defined in .env for external connections
      - "${KAFKA_EXTERNAL_PORT}:29092"
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: "zookeeper:2181"
      # Listeners configuration is key for connecting from both inside and outside Docker
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,PLAINTEXT_HOST://localhost:29092
      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 100 # Small delay for stability

  # Optional but highly recommended UI for Kafka
  redpanda-console:
    image: docker.redpanda.com/redpandadata/console:latest
    container_name: redpanda-console
    networks:
      - pap-platform-network
    depends_on:
      - kafka
    ports:
      - "${REDPANDA_CONSOLE_PORT}:8080"
    environment:
      KAFKA_BROKERS: "kafka:9092"
      # This allows the UI to create topics if needed
      KAFKA_CREATE_TOPICS_ENABLE: "true"

  # This service runs the topic creation script automatically
  topic-creator:
    image: confluentinc/cp-kafka:7.3.0
    container_name: topic-creator
    networks:
      - pap-platform-network
    depends_on:
      - kafka
    command: >
      bash -c "
        echo 'Waiting for Kafka to be available...' &&
        cub kafka-ready -b kafka:9092 1 30 &&
        echo 'Kafka is ready!' &&
        /etc/create-topics.sh
      "
    volumes:
      # Mount the script into the container
      - ./create-topics.sh:/etc/create-topics.sh

# Defines a shared network for all services to communicate
networks:
  pap-platform-network:
    driver: bridge