Kubernetes部署Bitnami Kafka遇arr[2]: unbound variable报错求助

问题场景 #

部署Bitnami Kafka镜像到Kubernetes时触发以下错误：

/opt/bitnami/scripts/libkafka.sh: line 364: arr[2]: unbound variable

使用的部署配置清单如下：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: event-bus-svc
spec:
  replicas: 1
  selector:
    matchLabels:
      app: event-bus-svc
  template:
    metadata:
      labels:
        app: event-bus-svc
    spec:
      containers:
        - name: event-bus-svc
          image: bitnami/kafka:latest
          imagePullPolicy: Never
          env:
            - name: KAFKA_CFG_NODE_ID
              value: "0"
            - name: KAFKA_CFG_PROCESS_ROLES
              value: "controller,broker"
            - name: KAFKA_CFG_LISTENERS
              value: "//kafka:9092,CONTROLLER://:9093"
            - name: KAFKA_CFG_LISTENER_SECURITY_PROTOCOL_MAP
              value: "CONTROLLER:PLAINTEXT,PLAINTEXT:PLAINTEXT"
            - name: KAFKA_CFG_CONTROLLER_QUORUM_VOTERS
              value: "0@kafka:9093"
            - name: KAFKA_CFG_CONTROLLER_LISTENER_NAMES
              value: "CONTROLLER"
            - name: KAFKA_CFG_ADVERTISED_LISTENERS
              value: "PLAINTEXT://kafka:9092"
---
apiVersion: v1
kind: Service
metadata:
  name: event-bus-clusterip-svc
spec:
  selector:
    app: event-bus-svc
  ports:
    - name: event-bus-src
      protocol: TCP
      port: 9092
      targetPort: 9092

错误原因 #

配置中的KAFKA_CFG_LISTENERS参数格式错误：第一个listener项//kafka:9092缺少协议前缀（如PLAINTEXT）。Bitnami的Kafka启动脚本会按://分割每个listener配置，没有协议前缀时，分割后的数组元素不足，导致脚本触发数组越界错误。

解决方法 #

修改KAFKA_CFG_LISTENERS的value，给第一个listener添加PLAINTEXT协议前缀：

- name: KAFKA_CFG_LISTENERS
  value: "PLAINTEXT://kafka:9092,CONTROLLER://:9093"

重新部署后，Kafka容器即可正常启动，服务可通过event-bus-clusterip-svc:9092访问。

内容的提问来源于stack exchange，提问作者Cleriston Martins Cardoso