docker-compose.yml

# Based on https://github.com/confluentinc/cp-docker-images/blob/master/examples/cp-all-in-one/docker-compose.yml

version: '3'
services:
  zookeeper:
    build:
      context: .
      dockerfile: kafka.Dockerfile
    command: >
      bash -c "/init.sh
      && confluent-community/bin/zookeeper-server-start confluent-community/etc/kafka/zookeeper.properties"
    hostname: zookeeper
    container_name: zookeeper
    ports:
      - 2181:2181
    environment:
      CONFIG_PATH: 'confluent-community/etc/kafka/zookeeper.properties'
      ZOOKEEPER_CLIENT_PORT: 2181

  kafka:
    build:
      context: .
      dockerfile: kafka.Dockerfile
    hostname: kafka
    container_name: kafka
    command: >
      bash -c "/wait-for-it.sh zookeeper:2181 -t 60
      && /init.sh
      && confluent-community/bin/kafka-server-start confluent-community/etc/kafka/server.properties"
    depends_on:
      - zookeeper
    ports:
      - 9092:9092
      - 9093:9093
    environment:
      CONFIG_PATH: 'confluent-community/etc/kafka/server.properties'
      KAFKA_ZOOKEEPER_CONNECT: 'zookeeper:2181'
      # We need zookeeper to advertise two different urls since the broker has to be reachable
      # from two different environments (once from inside the docker network and once from the host)
      # However it is neither possible to advertise two listeners but only configure one via KAFKA_LISTENERS
      # nor is it possible to advertise two listeners with the same protocol but different ports and hostnames since
      # they are still considered to have the same name.
      # We can do nothing about the former case but we can trick kafka with a custom protocol in the latter case.
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: 'LOCAL:PLAINTEXT,PLAINTEXT:PLAINTEXT'
      KAFKA_LISTENERS: 'LOCAL://:9092,PLAINTEXT://kafka:9093'
      KAFKA_ADVERTISED_LISTENERS: 'LOCAL://localhost:9092,PLAINTEXT://kafka:9093'