使用Docker搭建Apache Kafka环境
Docker是最受欢迎的容器引擎之一,软件行业用于创建、打包、部署应用。本教程学习如何使用Docker搭建Apache Kafka。
安装单个节点
安装单节点Kafka代理需能够满足本地开发需求,我们首先学习单节点安装。
docker-compose.yml 配置
使用Apache Kafka服务,首先需要启动Zookeeper 服务。这可以通过在docker-compose.yml 文件配置依赖实现,但要确保Zookeeper服务总是在Kafka服务之前启动,反之zookeeper最后停止。
首先创建docker-compose.yml文件,增加两个服务:zookeeper和kafka:
version: '2'
services:
zookeeper:
image: confluentinc/cp-zookeeper:latest
environment:
ZOOKEEPER_CLIENT_PORT: 2181
ZOOKEEPER_TICK_TIME: 2000
ports:
- 22181:2181
kafka:
image: confluentinc/cp-kafka:latest
depends_on:
- zookeeper
ports:
- 29092:29092
environment:
KAFKA_BROKER_ID: 1
KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,PLAINTEXT_HOST://localhost:29092
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
Zookeeper服务监听2181端口为Kafka提供服务,但对于运行在本机的客户端,暴露的端口为22181.
类似的,kafka通过端口29092暴露给主机应用,但实际上在容器中的端口9092。有KAFKA_ADVERTISED_LISTENERS属性来配置。
下面通过使用命令启动容器、开启kafka服务:
$ docker-compose up -d
Creating network "kafka_default" with the default driver
Creating kafka_zookeeper_1 ... done
Creating kafka_kafka_1 ... done
下面通过nc命令严重两个服务正在监听各自的端口:
$ nc -z localhost 22181
Connection to localhost port 22181 [tcp/*] succeeded!
$ nc -z localhost 29092
Connection to localhost port 29092 [tcp/*] succeeded!
另外,也可以检查日志,当容器正在运行时验证kafka服务是否启动:
$ docker-compose logs kafka | grep -i started
可以看到Kafka服务已经启动。
最后可以使用Kafka Tool Gui 工具连接已安装的Kafka服务:
安装集群环境
生产环境需要更稳定的环境,下面扩展 docker-compose.yml文件创建多节点集群环境:
docker-compose.yml配置
集群安装需要zookeeper和Kafka有多个实例,下面为zookeeper和kafka增加多个服务:
---
version: '2'
services:
zookeeper-1:
image: confluentinc/cp-zookeeper:latest
environment:
ZOOKEEPER_CLIENT_PORT: 2181
ZOOKEEPER_TICK_TIME: 2000
ports:
- 22181:2181
zookeeper-2:
image: confluentinc/cp-zookeeper:latest
environment:
ZOOKEEPER_CLIENT_PORT: 2181
ZOOKEEPER_TICK_TIME: 2000
ports:
- 32181:2181
kafka-1:
image: confluentinc/cp-kafka:latest
depends_on:
- zookeeper-1
- zookeeper-2
ports:
- 29092:29092
environment:
KAFKA_BROKER_ID: 1
KAFKA_ZOOKEEPER_CONNECT: zookeeper-1:2181,zookeeper-2:2181
KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka-1:9092,PLAINTEXT_HOST://localhost:29092
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
kafka-2:
image: confluentinc/cp-kafka:latest
depends_on:
- zookeeper-1
- zookeeper-2
ports:
- 39092:39092
environment:
KAFKA_BROKER_ID: 2
KAFKA_ZOOKEEPER_CONNECT: zookeeper-1:2181,zookeeper-2:2181
KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka-2:9092,PLAINTEXT_HOST://localhost:39092
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
必须要确保kafka服务名称唯一,通过KAFKA_BROKER_ID 属性设置。而且每个服务必须暴露唯一主机端口。虽然zookeeper-1 和 zookeeper-2 监听2181端口,但对于主机端口分别为 22181 和 32181。类似的,kafka-1 和 kafka-2 services对应主机端口分别为 29092 和 39092。
启动kafka集群
现在通过docker-compose命令启动集群:
$ docker-compose up -d
Creating network "kafka_default" with the default driver
Creating kafka_zookeeper-1_1 ... done
Creating kafka_zookeeper-2_1 ... done
Creating kafka_kafka-2_1 ... done
Creating kafka_kafka-1_1 ... done
启动完成,使用Kafka Tool连接集群,地址通过逗号分割只读多个zookeeper地址和端口:
总结
本文使用Docker技术创建单个Kafka节点和Kafka集群环境,并且使用可视化工具连接服务查看代理服务器的配置信息。