services:
  kafka:
    image: apache/kafka:latest
    container_name: kafka
    ports:
      - "9092:9092"
    environment:
      # Tryb KRaft (bez Zookeepera)
      # Two PLAINTEXT listeners: host apps use localhost:9092; containers (e.g. schema-registry) use kafka:29092.
      # Advertising only localhost breaks Docker-internal clients that bootstrap via kafka:9092.
      KAFKA_NODE_ID: 1
      KAFKA_PROCESS_ROLES: broker,controller
      KAFKA_LISTENERS: PLAINTEXT_HOST://0.0.0.0:9092,PLAINTEXT_INTERNAL://0.0.0.0:29092,CONTROLLER://0.0.0.0:9093
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT_HOST://localhost:9092,PLAINTEXT_INTERNAL://kafka:29092
      KAFKA_CONTROLLER_LISTENER_NAMES: CONTROLLER
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: CONTROLLER:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT,PLAINTEXT_INTERNAL:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT_INTERNAL
      KAFKA_CONTROLLER_QUORUM_VOTERS: 1@localhost:9093
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
      KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1
      KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1
  schema-registry:
    image: confluentinc/cp-schema-registry:7.5.0
    hostname: schema-registry
    container_name: schema-registry
    depends_on:
      - kafka
    ports:
      - "8081:8081"
    environment:
      SCHEMA_REGISTRY_HOST_NAME: schema-registry
      SCHEMA_REGISTRY_KAFKASTORE_BOOTSTRAP_SERVERS: 'kafka:29092'
      SCHEMA_REGISTRY_LISTENERS: http://0.0.0.0:8081
  kafka-ui:
    image: provectuslabs/kafka-ui:latest
    ports:
      - "7777:8080"
    environment:
      KAFKA_CLUSTERS_0_NAME: local
      KAFKA_CLUSTERS_0_BOOTSTRAPSERVERS: kafka:9092
      KAFKA_CLUSTERS_0_SCHEMAREGISTRY: http://schema-registry:8081