CONNECT_BOOTSTRAP_SERVERS does not work with connector container

[samko635]

I've deployed docker-compose as below but connector container cannot seem to be able to connect to brokers properly.

I've set CONNECT_BOOTSTRAP_SERVERS to correct hostname but connector is trying to connect to "localhost" instead of given hostnames. Zookeepers and brokers are deployed without a problem and can talk to each other with given hostnames. I don't know why this is only problem for connector image.

version: '2.1'

services:
  zoo1:
    image: zookeeper:3.4.9
    hostname: zoo1
    ports:
      - "2181:2181"
    networks: 
     - my-kafka
    environment:
        ZOO_MY_ID: 1
        ZOO_PORT: 2181
        ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888
    volumes:
      - ./zk-multiple-kafka-multiple/zoo1/data:/data
      - ./zk-multiple-kafka-multiple/zoo1/datalog:/datalog

  zoo2:
    image: zookeeper:3.4.9
    hostname: zoo2
    ports:
      - "2182:2182"
    networks: 
     - my-kafka
    environment:
        ZOO_MY_ID: 2
        ZOO_PORT: 2182
        ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888
    volumes:
      - ./zk-multiple-kafka-multiple/zoo2/data:/data
      - ./zk-multiple-kafka-multiple/zoo2/datalog:/datalog

  zoo3:
    image: zookeeper:3.4.9
    hostname: zoo3
    ports:
      - "2183:2183"
    networks: 
     - my-kafka
    environment:
        ZOO_MY_ID: 3
        ZOO_PORT: 2183
        ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888
    volumes:
      - ./zk-multiple-kafka-multiple/zoo3/data:/data
      - ./zk-multiple-kafka-multiple/zoo3/datalog:/datalog

  kafka1:
    image: confluentinc/cp-kafka:5.3.1
    hostname: kafka1
    ports:
      - "9092:9092"
    networks: 
     - my-kafka
    environment:
      KAFKA_ADVERTISED_LISTENERS: LISTENER_DOCKER_INTERNAL://kafka1:19092,LISTENER_DOCKER_EXTERNAL://${DOCKER_HOST_IP:-127.0.0.1}:9092
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: LISTENER_DOCKER_INTERNAL:PLAINTEXT,LISTENER_DOCKER_EXTERNAL:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: LISTENER_DOCKER_INTERNAL
      KAFKA_ZOOKEEPER_CONNECT: "zoo1:2181,zoo2:2182,zoo3:2183"
      KAFKA_BROKER_ID: 1
      KAFKA_LOG4J_LOGGERS: "kafka.controller=INFO,kafka.producer.async.DefaultEventHandler=INFO,state.change.logger=INFO"
    volumes:
      - ./zk-multiple-kafka-multiple/kafka1/data:/var/lib/kafka/data
    depends_on:
      - zoo1
      - zoo2
      - zoo3

  kafka2:
    image: confluentinc/cp-kafka:5.3.1
    hostname: kafka2
    ports:
      - "9093:9093"
    networks: 
     - my-kafka
    environment:
      KAFKA_ADVERTISED_LISTENERS: LISTENER_DOCKER_INTERNAL://kafka2:19093,LISTENER_DOCKER_EXTERNAL://${DOCKER_HOST_IP:-127.0.0.1}:9093
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: LISTENER_DOCKER_INTERNAL:PLAINTEXT,LISTENER_DOCKER_EXTERNAL:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: LISTENER_DOCKER_INTERNAL
      KAFKA_ZOOKEEPER_CONNECT: "zoo1:2181,zoo2:2182,zoo3:2183"
      KAFKA_BROKER_ID: 2
      KAFKA_LOG4J_LOGGERS: "kafka.controller=INFO,kafka.producer.async.DefaultEventHandler=INFO,state.change.logger=INFO"
    volumes:
      - ./zk-multiple-kafka-multiple/kafka2/data:/var/lib/kafka/data
    depends_on:
      - zoo1
      - zoo2
      - zoo3

  kafka3:
    image: confluentinc/cp-kafka:5.3.1
    hostname: kafka3
    ports:
      - "9094:9094"
    networks: 
     - my-kafka
    environment:
      KAFKA_ADVERTISED_LISTENERS: LISTENER_DOCKER_INTERNAL://kafka3:19094,LISTENER_DOCKER_EXTERNAL://${DOCKER_HOST_IP:-127.0.0.1}:9094
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: LISTENER_DOCKER_INTERNAL:PLAINTEXT,LISTENER_DOCKER_EXTERNAL:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: LISTENER_DOCKER_INTERNAL
      KAFKA_ZOOKEEPER_CONNECT: "zoo1:2181,zoo2:2182,zoo3:2183"
      KAFKA_BROKER_ID: 3
      KAFKA_LOG4J_LOGGERS: "kafka.controller=INFO,kafka.producer.async.DefaultEventHandler=INFO,state.change.logger=INFO"
    volumes:
      - ./zk-multiple-kafka-multiple/kafka3/data:/var/lib/kafka/data
    depends_on:
      - zoo1
      - zoo2
      - zoo3

  connect:
    image: confluentinc/cp-kafka-connect:5.3.1
    ports:
      - 8083:8083
    networks:
      - my-kafka
    environment:
      - CONNECT_BOOTSTRAP_SERVERS="kafka1:9092,kafka2:9093,kafka3:9094"
      - CONNECT_REST_PORT=8083
      - CONNECT_GROUP_ID="quickstart-avro"
      - CONNECT_CONFIG_STORAGE_TOPIC="quickstart-avro-config"
      - CONNECT_OFFSET_STORAGE_TOPIC="quickstart-avro-offsets"
      - CONNECT_STATUS_STORAGE_TOPIC="quickstart-avro-status"
      - CONNECT_CONFIG_STORAGE_REPLICATION_FACTOR=1
      - CONNECT_OFFSET_STORAGE_REPLICATION_FACTOR=1
      - CONNECT_STATUS_STORAGE_REPLICATION_FACTOR=1
      - CONNECT_INTERNAL_KEY_CONVERTER="org.apache.kafka.connect.json.JsonConverter"
      - CONNECT_INTERNAL_VALUE_CONVERTER="org.apache.kafka.connect.json.JsonConverter"
      - CONNECT_REST_ADVERTISED_HOST_NAME="localhost"
      - CONNECT_LOG4J_ROOT_LOGLEVEL=DEBUG
      - CONNECT_PLUGIN_PATH=/usr/share/java/
      - CONNECT_KEY_CONVERTER="org.apache.kafka.connect.json.JsonConverter"
      - CONNECT_VALUE_CONVERTER="org.apache.kafka.connect.json.JsonConverter"
    depends_on:
      - kafka1
      - kafka2
      - kafka3

networks:
  my-kafka:
    name: my-kafka
    driver: bridge