本文介绍基于docker搭建的confluent-kafka及其python接口的使用。

本文采用的系统配置如下：

• LinuxMint 20.3 （兼容 Ununtu 20.04）
• docker 20.10.21
• docker-compose 2.14.2
• python 3.9.16
• confluent-kafka(python包) 2.1.1

1. 安装docker以及docker-compose

1.1 安装docker

docker-compose依赖于docker，因此需要先安装docker。

curl -fsSL https://test.docker.com -o test-docker.sh
sudo sh test-docker.sh

1.2 安装docker-compose

Compose 是用于定义和运行多容器 Docker 应用程序的工具。通过 Compose，您可以使用 YML 文件来配置应用程序需要的所有服务。然后，使用一个命令，就可以从 YML 文件配置中创建并启动所有服务。

curl -L https://get.daocloud.io/docker/compose/releases/download/v2.14.2/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose

要安装其他版本的 Compose，请替换 v2.14.2。

2. 安装confluent-kafka

新建文件并创建docker-compose.yml文件：

version: '3'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:7.0.1
    container_name: zookeeper
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000

  broker:
    image: confluentinc/cp-kafka:7.0.1
    container_name: broker
    ports:
    # To learn about configuring Kafka for access across networks see
    # https://www.confluent.io/blog/kafka-client-cannot-connect-to-broker-on-aws-on-docker-etc/
      - "9092:9092"
    depends_on:
      - zookeeper
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: 'zookeeper:2181'
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_INTERNAL:PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://localhost:9092,PLAINTEXT_INTERNAL://broker:29092
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1
      KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1

进入该文件夹并运行：

docker-compose -f docker-compose.yml up -d

运行后在docker中看到类似结果说明启动成功：

aa@bb:~/docker_scripts$ docker ps
CONTAINER ID   IMAGE                             COMMAND                  CREATED         STATUS         PORTS                                       NAMES
e6fbc05d61b1   confluentinc/cp-kafka:7.0.1       "/etc/confluent/dock…"   7 minutes ago   Up 7 minutes   0.0.0.0:9092->9092/tcp, :::9092->9092/tcp   broker
58b04385f2bf   confluentinc/cp-zookeeper:7.0.1   "/etc/confluent/dock…"   7 minutes ago   Up 7 minutes   2181/tcp, 2888/tcp, 3888/tcp                zookeeper

这里kafka端口为9092。

关闭容器服务：

docker-compose -f docker-compose.yml down

3. python接口使用

3.1 安装依赖包

安装依赖包：

pip3 install confluent-kafka

3.2 创建、查看topic

进入kafka镜像：

docker exec -ti broker bash

查看topic：

[aa@bb ~]$ /bin/kafka-topics --list --bootstrap-server 127.0.0.1:9092

新建名为test001的topic：

[aa@bb ~]$ /bin/kafka-topics --create --bootstrap-server 127.0.0.1:9092 --topic test001 --partitions 2
Created topic test001.

查看topic：

[aa@bb ~]$ /bin/kafka-topics --list --bootstrap-server 127.0.0.1:9092
test001

通过Ctrl + P + Q回到终端。

3.3 python接口-broker

创建producer代码producer1.py：

import socket

from confluent_kafka import Producer

conf = {
    'bootstrap.servers': "localhost:9092",
    'client.id': socket.gethostname()
}

producer = Producer(conf)


def __publish_delivery_report(err, msg) -> None:
    if err is not None:
        print(f"send msg:{msg} fail, err is not None")
    else:
        print(f"send msg{msg} success")


def send_msg(topic: str, data):
    producer.produce(topic, data, callback=__publish_delivery_report)
    producer.flush()


if __name__ == '__main__':
    msg = "hello kafka"
    topic = "test001"
    send_msg(topic, msg)

运行结果：

aa@bb:~/codes/kafka_test$ python3 producer1.py
send msg<cimpl.Message object at 0x7f8d6fe6acc0> success

3.4 python接口-consumer

创建consumer代码consumer1.py：

from confluent_kafka import Consumer
 

class KafkaConsumer:
    def __init__(self, brokers, group):
        config = dict()
        config['bootstrap.servers'] = brokers
        config['group.id'] = group
        config['auto.offset.reset'] = 'earliest'
        self.consumer = Consumer(config)
 
    def subscribe(self, topics):
        self.consumer.subscribe(topics=topics)
 
    def pull(self):
        while True:
            msg = self.consumer.poll(1.0)
            if msg is None:
                continue
            if msg.error():
                print("Consumer error: {}".format(msg.error()))
                continue
            print('Received message: {}'.format(msg.value().decode('utf-8')))
 
    def close(self):
        self.consumer.close()
 
 
if __name__ == "__main__":
    consumer = KafkaConsumer("127.0.0.1:9092", "test_group1")
    consumer.subscribe(['test001'])
    consumer.pull()
    consumer.close()

运行结果：

aa@bb:~/codes/kafka_test$ python3 consumer1.py
Received message: hello kafka

参考链接

1. Hello Kafka（八）——Confluent Kafka简介
2. Docker Compose | 菜鸟教程
3. confluent_kafka生产者 - luckygxf - 博客园
4. Hello Kafka（十二）——Python客户端_kafka python客户端_天山老妖的博客-CSDN博客