Docker-Compose for Kafka and Zookeeper with internal and external listeners

docker-compose.yml

---
version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:latest
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000

  kafka:
    # "`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-
    # An important note about accessing Kafka from clients on other machines: 
    # -----------------------------------------------------------------------
    #
    # The config used here exposes port 29092 for _external_ connections to the broker
    # i.e. those from _outside_ the docker network. This could be from the host machine
    # running docker, or maybe further afield if you've got a more complicated setup. 
    # If the latter is true, you will need to change the value 'localhost' in 
    # KAFKA_ADVERTISED_LISTENERS to one that is resolvable to the docker host from those 
    # remote clients
    #
    # For connections _internal_ to the docker network, such as from other services
    # and components, use kafka:9092.
    #
    # See https://rmoff.net/2018/08/02/kafka-listeners-explained/ for details
    # "`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-'"`-._,-
    #
    image: confluentinc/cp-kafka:latest
    depends_on:
      - zookeeper
    ports:
      - 29092:29092
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,PLAINTEXT_HOST://localhost:29092
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1

If you're on a mac and running into Connection to node -1 (localhost/127.0.0.1:29092) could not be established. Broker may not be available., replace localhost with host.docker.internal. Now KAFKA_ADVERTISED_LISTENERS should look like the following,

      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,PLAINTEXT_HOST://host.docker.internal:29092

Note that if you're connecting to kafka from another container, you'll need to replace localhost in the client's bootstrap servers with host.docker.internal as well.

If you are getting Broker may not be available. then make sure you are connecting to the container using docker-compose exec kafka bash, not docker exec -it <CONTAINER_ID> bash

Thank you very much! It was a life-saver!

I have a doubt, why are we port mapping 29092:29092, shouldn't it be 29092:9092, because kafka provides services at port no: 9092