Multi-node Kafka cluster (three brokers)

docker-compose.yml

---
version: '3.8'
services:
  zookeeper-1:
    image: confluentinc/cp-zookeeper:5.5.1
    ports:
      - '32181:32181'
    environment:
      ZOOKEEPER_CLIENT_PORT: 32181
      ZOOKEEPER_TICK_TIME: 2000


  kafka-1:
    image: confluentinc/cp-kafka:5.5.1
    ports:
      - '9092:9092'
    depends_on:
      - zookeeper-1
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: zookeeper-1:32181
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL
      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka-1:29092,EXTERNAL://localhost:9092
      KAFKA_DEFAULT_REPLICATION_FACTOR: 3
      KAFKA_NUM_PARTITIONS: 3


  kafka-2:
    image: confluentinc/cp-kafka:5.5.1
    ports:
      - '9093:9093'
    depends_on:
      - zookeeper-1
    environment:
      KAFKA_BROKER_ID: 2
      KAFKA_ZOOKEEPER_CONNECT: zookeeper-1:32181
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL
      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka-2:29093,EXTERNAL://localhost:9093
      KAFKA_DEFAULT_REPLICATION_FACTOR: 3
      KAFKA_NUM_PARTITIONS: 3
    

  kafka-3:
    image: confluentinc/cp-kafka:5.5.1
    ports:
      - '9094:9094'
    depends_on:
      - zookeeper-1
    environment:
      KAFKA_BROKER_ID: 3
      KAFKA_ZOOKEEPER_CONNECT: zookeeper-1:32181
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL
      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka-3:29094,EXTERNAL://localhost:9094
      KAFKA_DEFAULT_REPLICATION_FACTOR: 3
      KAFKA_NUM_PARTITIONS: 3

To understand listeners see https://www.confluent.io/blog/kafka-client-cannot-connect-to-broker-on-aws-on-docker-etc

╰─$ docker run --network host --interactive --rm edenhill/kafkacat:1.6.0 -b localhost:9093 -L                                                                                             1 ↵
Metadata for all topics (from broker 2: localhost:9093/2):
 3 brokers:
  broker 2 at localhost:9093
  broker 3 at localhost:9094
  broker 1 at localhost:9092 (controller)
 1 topics:
  topic "__confluent.support.metrics" with 1 partitions:
    partition 0, leader 3, replicas: 3,2,1, isrs: 3,2,1

╰─$ docker run --network tmp_default --interactive --rm edenhill/kafkacat:1.6.0 -b kafka-2:29093 -L
Metadata for all topics (from broker 2: kafka-2:29093/2):
 3 brokers:
  broker 2 at kafka-2:29093
  broker 3 at kafka-3:29094
  broker 1 at kafka-1:29092 (controller)
 1 topics:
  topic "__confluent.support.metrics" with 1 partitions:
    partition 0, leader 3, replicas: 3,2,1, isrs: 3,2,1