Docker容器网络- Kafka生产者

Question

我想产生从容器A到容器B中的Kafka主题的消息，但我面临着一些与这些容器的网络有关的奇怪问题。你知道如何以正确的方式连接这些容器吗？问题是收集服务程序无法从另一个容器中看到kafka，也无法向其中添加消息。更具体地说，我有以下服务：

docker-compose.yml

version: '3.5'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:latest
    ports:
      - "2181:2181"
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000
      ADVERTISED_HOST: zookeeper
      ADVERTISED_PORT: 2181
    extra_hosts:
      - "moby:127.0.0.1"
    networks:
      - meetup-net

  kafka:
    image: confluentinc/cp-kafka:latest
    depends_on:
      - zookeeper
    ports:
      - "9092:9092"
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://localhost:9092
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
    extra_hosts:
      - "moby:127.0.0.1"
    networks:
      - meetup-net

collector:
    image: collector:v1
    environment:
      - kafka-bootstrap-servers=docker_kafka_1.docker_meetup-net
    restart: always
    depends_on:
      - kafka
    networks:
      - meetup-net
networks:
  meetup-net:
    driver: bridge

在另一端，我有application.conf文件

streaming {
  window-size = 50
  window-interval = 5

  kafka-bootstrap-servers = ${?kafka-bootstrap-servers}
  kafka-bootstrap-servers = "localhost:9092"

  sink-topic = ${?source-topic}
  sink-topic = "meetup"

  key-value-json-path = ${key-value-json-path}
  key-value-json-path = "./data/keyvalue"

  source-topic-checkpoint-location = ${source-topic-checkpoint-location}
  source-topic-checkpoint-location = "./target/source-topic"

  sink-topic-checkpoint-location = ${sink-topic-checkpoint-location}
  sink-topic-checkpoint-location = "./target/sink-topic"
}

zookeeper.server = ${?zookeeper-server}
zookeeper.server = "localhost:2181"

Answer 1

您需要正确设置KAFKA_ADVERTISED_LISTENERS。

目前，KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://localhost:9092意味着连接到代理的任何客户端都将获得localhost作为代理地址，后续请求将在该地址上连接。除非客户端在代理上运行(它不在这里)，否则您需要更改此配置。对于在一个自包含的Docker环境中运行，这非常简单：

KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:29092,PLAINTEXT_HOST://localhost:9092

现在，任何客户端连接都应该是到kafka:29092的。这也意味着您可以将运行在Docker主机上的客户端连接到Kafka代理，这可能很有用，例如，当在笔记本电脑上运行和在本地运行客户端时。

Here是一个示例Docker Compose，它在实践中展示了这一点。

有关更多详细信息和背景，请参阅https://rmoff.net/2018/08/02/kafka-listeners-explained/