我需要创建一个已创建主题的 kafka 图像

Question

我有一个要求，我需要在本地设置 kafka，主题已经存在于容器中。我正在使用它ladoop/fast-data-dev来做到这一点

我是如何手动做的-

docker run -d --name landoopkafka -p 2181:2181 -p 3030:3030 -p 8081:8081 -p 8082:8082 -p 8083:8083 -p 9092:9092 -e ADV_HOST=localhost landoop/fast-data-dev

运行此命令后，我的容器已启动并正在运行。

现在我像 docker -exec -it landopkafka bash 一样进入这个容器内的 bash

并使用此命令创建主题

kafka-topics --zookeeper localhost:2181 --create --topic hello_topic --partitions 1 --replication-factor 1

我的主题已创建。

但我的要求是我需要一个 docker 文件，该文件将创建主题，我只需要运行它。

或者

我需要运行的 docker compose 文件

伙计们，我需要这方面的帮助，因为我对 docker 和 kafka 完全陌生

Answer 1

我也必须这样做！如果我不想使用香肠图片怎么办？我决定制作一个自定义脚本来完成这项工作，并在单独的容器中运行该脚本。

存储库

https://github.com/yan-khonski-it/kafka-compose

请注意，它将与使用Zookeeper的 kafka 版本一起使用。 Zookeeper是Kafka必须的吗？

使用您所有的主题和 Zookeeper 启动 kafka -docker-compose up -d。

实施细节。

docker-compose.yml

# These services are kafka related. This docker-compose allows to start kafka locally quickly.

version: '2.1'

networks:
  demo-network:
    name: demo-network
    driver: bridge

services:
  zookeeper:
    image: "confluentinc/cp-zookeeper:${CONFLUENT_PLATFORM_VERSION}"
    container_name: zookeeper
    environment:
      ZOOKEEPER_CLIENT_PORT: 32181
      ZOOKEEPER_TICK_TIME: 2000
    ports:
      - 32181:32181
    hostname: zookeeper
    networks:
      - demo-network

  kafka:
    image: "confluentinc/cp-kafka:${CONFLUENT_PLATFORM_VERSION}"
    container_name: kafka
    hostname: kafka
    ports:
      - 9092:9092
      - 29092:29092

    environment:
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:32181
      KAFKA_BROKER_ID: 1
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://localhost:9092,PLAINTEXT_HOST://kafka:29092
      LISTENERS: PLAINTEXT://0.0.0.0:9092
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1

    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    depends_on:
      - "zookeeper"
    networks:
      - demo-network

  # Automatically creates required kafka topics if they were not created.
  kafka-topics-creator:
    build:
      context: kafka-topic-creator
      dockerfile: Dockerfile
    container_name: kafka-topics-creator
    depends_on:
      - zookeeper
      - kafka
    environment:
      ZOOKEEPER_HOSTS: "zookeeper:32181"
      KAFKA_TOPICS: "topic_v1 topic_v2"
    networks:
      - demo-network

然后我有一个目录kafka-topics-creator。在这里，我有三个文件 create-kafka-topics.sh, Dockerfile, README.md.

Dockerfile

# It is recommened to use same version as kafka broker is used.
# So no additional images are pulled.
FROM confluentinc/cp-kafka:4.1.2

WORKDIR usr/bin

# Once it is executed, this container is not needed.
COPY create-kafka-topics.sh create-kafka-topics.sh
ENTRYPOINT ["./create-kafka-topics.sh"]

创建-kafka-topics.sh

#!/bin/bash

# Simply wait until original kafka container and zookeeper are started.
sleep 15.0s

# Parse string of kafka topics into an array
# /sf/answers/741031861/
kafkatopicsArrayString="$KAFKA_TOPICS"
IFS=' ' read -r -a kafkaTopicsArray <<< "$kafkatopicsArrayString"

# A separate variable for zookeeper hosts.
zookeeperHostsValue=$ZOOKEEPER_HOSTS

# Create kafka topic for each topic item from split array of topics.
for newTopic in "${kafkaTopicsArray[@]}"; do
  # https://kafka.apache.org/quickstart
  kafka-topics --create --topic "$newTopic" --partitions 1 --replication-factor 1 --if-not-exists --zookeeper "$zookeeperHostsValue"
done

README.md - 这样其他人就知道如何使用它。始终记录你的东西 - 好建议。

# Creates kafka topics automatically.

## Parameters
`ZOOKEEPER_HOSTS` - zookeeper hosts,  I used value `"zookeeper:32181"` to run it locally.

`KAFKA_TOPICS` - space separated list of kafka topics. Example, `topic_1, topic_2, topic_3`.

Note, this container should run only **after** your original kafka broker and zookeeper are running.
After this container creates topics, it is not needed anymore.

如何检查主题是否已创建。

一种解决方案是检查kafka-topics-creator容器的日志。

docker logs kafka-topics-creator应该打印

$ docker logs kafka-topics-creator
WARNING: Due to limitations in metric names, topics with a period ('.') or underscore ('_') could collide. To avoid issues it is best to use either, but not both.
Created topic "topic_v1".
WARNING: Due to limitations in metric names, topics with a period ('.') or underscore ('_') could collide. To avoid issues it is best to use either, but not both.
Created topic "topic_v2".

Answer 2

您应该尝试使用 wurstmeister/kafka 镜像，它支持环境变量在容器启动期间创建主题。

当然，Landoop 容器还有很多其他有用的东西，但听起来你只想要 Kafka 并且不想编辑任何 Dockerfile

另一个解决方案是在 Kafka 之后启动第二个容器，该容器运行创建脚本，然后自行停止