使用 Docker 啟動不依賴 ZooKeeper 的 Kafka

之前筆記試試不依賴 ZooKeeper 的 Kafka 紀錄到如何使用 Kafka 的 Preview Release (KRaft mode) 功能：不再依賴 ZooKeeper，雖然已經是大幅降低了安裝與設定的難度，但還是比不上 container 的一鍵啟動，所以今天就來紀錄一下如何使用 docker compose 來快速啟動沒有 ZooKeeper 的 Kafka

基本環境說明

macOS Monterey 12.1
docker desktop 4.2.0(70708)
container images
- quay.io/strimzi/kafka:latest-kafka-3.1.0-amd64

設定方式

server.properties

process.roles=broker,controller
node.id=1
offsets.topic.replication.factor=1
controller.quorum.voters=1@kafka:9093
listeners=PLAINTEXT://:9092,CONTROLLER://:9093
advertised.listeners=PLAINTEXT://kafka:9092
controller.listener.names=CONTROLLER
listener.security.protocol.map=CONTROLLER:PLAINTEXT,PLAINTEXT:PLAINTEXT
log.dirs=kafka_data

docker-compose.yaml

這邊需要特別留意的是使用 root user

version: '3'
services:
  kafka:
    container_name: kafka
    user: root
    image: quay.io/strimzi/kafka:latest-kafka-3.1.0-amd64
    volumes:
      - "./server.properties:/opt/kafka/config/kraft/server.properties"
    command:
      [
        "sh",
        "-c",
        "bin/kafka-storage.sh format -t $$(bin/kafka-storage.sh random-uuid) -c /opt/kafka/config/kraft/server.properties && bin/kafka-server-start.sh /opt/kafka/config/kraft/server.properties",
      ]
    ports:
      - "9092:9092"

未使用 root 的錯誤

log.dirs

錯誤訊息

Creating network "kafka-without-zookeeper_default" with the default driver
Creating kafka ... done
Attaching to kafka
kafka    | Unable to create storage directory /opt/kafka/kafka_data: /opt/kafka/kafka_data
kafka exited with code 1

錯誤截圖

可能解決方式

在 host 上建立 folder 透過 volume bind 的方式提供使用

version: '3'
services:
  kafka:
    container_name: kafka
    image: quay.io/strimzi/kafka:latest-kafka-3.1.0-amd64
    volumes:
      - "./server.properties:/opt/kafka/config/kraft/server.properties"
      - type: bind
        source: ./kafka_data
        target: /opt/kafka/kafka_data
    command:
      [
        "sh",
        "-c",
        "bin/kafka-storage.sh format -t $$(bin/kafka-storage.sh random-uuid) -c /opt/kafka/config/kraft/server.properties && bin/kafka-server-start.sh /opt/kafka/config/kraft/server.properties",
      ]
    ports:
      - "9092:9092"

kafkaServer-gc.log

因為不知道 kafkaServer-gc.log 儲存 path 的設定位置，所以我放棄 bind volume 的做法

錯誤訊息

Creating network "kafka-without-zookeeper_default" with the default driver
Creating kafka ... done
Attaching to kafka
kafka    | Formatting kafka_data
kafka    | mkdir: cannot create directory '/opt/kafka/bin/../logs': Permission denied
kafka    | [0.001s][error][logging] Error opening log file '/opt/kafka/bin/../logs/kafkaServer-gc.log': No such file or directory
kafka    | [0.001s][error][logging] Initialization of output 'file=/opt/kafka/bin/../logs/kafkaServer-gc.log' using options 'filecount=10,filesize=100M' failed.
kafka    | Invalid -Xlog option '-Xlog:gc*:file=/opt/kafka/bin/../logs/kafkaServer-gc.log:time,tags:filecount=10,filesize=100M', see error log for details.
kafka    | Error: Could not create the Java Virtual Machine.
kafka    | Error: A fatal exception has occurred. Program will exit.
kafka exited with code 1

錯誤截圖

心得

用 root user 啟動不是很漂亮，畢竟有資安的風險，所以主流是 rootless，不過我不想多花時間去解決 folder 權限問題，畢竟用 container 啟動 kafka 的情境應該是測試或 local 開發為主，除此之外將 container 資料 mount 到 host 上會需要在每次重新啟動前都執行清除前次資料的動作，我個人覺得不是很直覺，無法享受 container 一鍵啟動(repeatable) 的好處

完整程式碼請參考 yowko/kafka-without-zookeeper

文章目錄

使用 Docker 啟動不依賴 ZooKeeper 的 Kafka

基本環境說明

設定方式

心得

參考資訊