docker-compose.yml

version: '3.8'

networks:
  kafka_network:
    name: kafka_network

services:
  zookeeper_server:
    image: confluentinc/cp-zookeeper:7.0.1
    container_name: zookeeper_server
    hostname: zookeeper_server
    networks:
      - kafka_network
    restart: always
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
    ports:
      - "2181:2181"
    healthcheck:
      test: "echo stat | nc localhost $$ZOOKEEPER_CLIENT_PORT"
      interval: 30s
      timeout: 10s
      retries: 10
      
  kafka_server:
    image: confluentinc/cp-kafka:7.0.1
    container_name: kafka_server
    hostname: kafka_server
    networks:
      - kafka_network
    restart: always
    depends_on:
      - zookeeper_server
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: zookeeper_server:2181
      # Ref: https://www.youtube.com/watch?v=L--VuzFiYrM
      # INTERNAL -- Kafka-Broker & Kafka-Client both running in Docker within the same Docker network, in just different containers
      #          > docker run -it --rm --name kafka_client_producer --network kafka_network confluentinc/cp-kafka:7.0.1 /bin/kafka-console-producer --bootstrap-server kafka_server:29092 --topic test_topic
      #          > docker run -it --rm --name kafka_client_consumer --network kafka_network confluentinc/cp-kafka:7.0.1 /bin/kafka-console-consumer --bootstrap-server kafka_server:29092 --topic test_topic
      # EXTERNAL_SAME_HOST -- Kafka-Broker running in Docker and Kafka-Client on local machine
      #          > kafka-console-producer --bootstrap-server localhost:9092 --topic test_topic_2
      #          > kafka-console-consumer --bootstrap-server localhost:9092 --topic test_topic_2
      # EXTERNAL_DIFFERENT_HOST -- Kafka-Broker running on external server ex. cloud and 157.245.80.232 is it's IP Address (better use DNS Names instead of IP)
      #          > kafka-console-producer --bootstrap-server 157.245.80.232:29093 --topic test_topic_3
      #          > kafka-console-consumer --bootstrap-server 157.245.80.232:29093 --topic test_topic_3
      KAFKA_LISTENERS: EXTERNAL_SAME_HOST://:9092,EXTERNAL_DIFFERENT_HOST://:29093,INTERNAL://:29092
      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka_server:29092,EXTERNAL_SAME_HOST://localhost:9092,EXTERNAL_DIFFERENT_HOST://157.245.80.232:29093
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL_SAME_HOST:PLAINTEXT,EXTERNAL_DIFFERENT_HOST:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_SCHEMA_REGISTRY_URL: "schema_registry:8081"
    ports:
      - "9092:9092"
      - "29093:29093"
    healthcheck:
      # test: [ "CMD", "nc", "-z", "localhost", "9092" ]
      test: ["CMD", "kafka-topics", "--bootstrap-server", "kafka_server:9092", "--list"]
      interval: 30s
      timeout: 10s
      retries: 10

  schema_registry:
    image: confluentinc/cp-schema-registry:7.3.1
    container_name: schema_registry
    hostname: schema_registry
    networks:
      - kafka_network
    restart: always
    depends_on:
      - zookeeper_server
    environment:
      SCHEMA_REGISTRY_KAFKASTORE_BOOTSTRAP_SERVERS: "PLAINTEXT://kafka_server:29092"
      SCHEMA_REGISTRY_HOST_NAME: schema_registry
      SCHEMA_REGISTRY_LISTENERS: "http://0.0.0.0:8081"
    ports:
      - "8081:8081"
    healthcheck:
      test: ["CMD", "curl", "--output", "/dev/null", "--silent", "--head", "--fail", "http://schema_registry:8081/subjects"]
      interval: 30s
      timeout: 10s
      retries: 10