docker - 在docker-compose.yml中了解容器的主机名

Question

我正在尝试了解 docker-compose.yml (也显示在本文的底部)。

问题: confluent:2181用于以下行

KAFKA_ZOOKEEPER_CONNECT: "confluent:2181"

这个confluent主机名是如何定义的？如果我正确理解了Docker中的主机名，则唯一的容器主机名是zookeeper，kafka，rest-proxy和schema-registry。

docker-compose.yml

version: "2"
services:
    zookeeper:
        image: confluent/zookeeper
        ports:
        - "2181:2181"
        environment:
        zk_id: "1"
        network_mode: "host"
    kafka:
        image: confluent/kafka
        depends_on:
        - zookeeper
        ports:
        - "9092:9092"
        environment:
        KAFKA_ZOOKEEPER_CONNECT: "confluent:2181"
        network_mode: "host"
    rest-proxy:
        image: confluent/rest-proxy
        depends_on:
        - zookeeper
        - kafka
        - schema-registry
        ports:
        - "8082:8082"
        environment:
        RP_ZOOKEEPER_CONNECT: "confluent:2181"
        RP_SCHEMA_REGISTRY_URL: "http://confluent:8081"
        network_mode: "host"
    schema-registry:
        image: confluent/schema-registry
        depends_on:
        - kafka
        - zookeeper
        ports:
        - "8081:8081"
        environment:
        SR_KAFKASTORE_CONNECTION_URL: "confluent:2181"
        network_mode: "host"

Answer 1

你是对的。根据docker-compose.yml，所定义的服务将仅针对zookeeper，kafka，rest-proxy和schema-registry提供DNS解析，而不提供confluent。
但是，如果您使用take a look at the documenttion from confluentinc，则要求您修改主机中的主机文件:

Edit your hosts file and add a host entry for the docker machine.

192.168.99.100 confluent

这就是为什么您可以使用confluent并获得名称解析的原因。它与docker或compose无关。
附注:请注意您使用的图像已弃用according to their documentation