Kafka NodePort 服务在集群外无法访问 [英] Kafka NodePort service is unreachable outside of cluster

问题描述

我一直在尝试使用 掌舵图.所以我为 Kafka pod 定义了 NodePort 服务.我使用相同的主机和端口检查了控制台 Kafka 生产者和消费者 - 它们工作正常.但是，当我创建 Spark 应用程序作为数据消费者和 Kafka 作为生产者时，他们无法连接到 Kafka service0.我使用 minikube ip(而不是节点 ip)作为主机和服务 NodePort 端口.虽然，在 Spark 日志中，我看到 NodePort 服务解析端点，代理被发现为 Pod 寻址和端口:

I have been trying to deploy Kafka using Helm charts. So I defined NodePort service for Kafka pods. I checked console Kafka producer and consumer with the same hosts and ports - they work properly. However, when I create Spark application as data consumer and Kafka as producer they are not able to connect to the Kafka service0. I used minikube ip (instead of node ip) for the host and service NodePort port. Although, in Spark logs, I saw that NodePort service resolves endpoints and brokers are discovered as pods addressed and ports:

INFO AbstractCoordinator: [Consumer clientId=consumer-1, groupId=avro_data] Discovered group coordinator 172.17.0.20:9092 (id: 2147483645 rack: null)
INFO ConsumerCoordinator: [Consumer clientId=consumer-1, groupId=avro_data] Revoking previously assigned partitions []
INFO AbstractCoordinator: [Consumer clientId=consumer-1, groupId=avro_data] (Re-)joining group
WARN NetworkClient: [Consumer clientId=consumer-1, groupId=avro_data] Connection to node 2147483645 (/172.17.0.20:9092) could not be established. Broker may not be available.
INFO AbstractCoordinator: [Consumer clientId=consumer-1, groupId=avro_data] Group coordinator 172.17.0.20:9092 (id: 2147483645 rack: null) is unavailable or invalid, will attempt rediscovery
WARN NetworkClient: [Consumer clientId=consumer-1, groupId=avro_data] Connection to node 2 (/172.17.0.20:9092) could not be established. Broker may not be available.
WARN NetworkClient: [Consumer clientId=consumer-1, groupId=avro_data] Connection to node 0 (/172.17.0.12:9092) could not be established. Broker may not be available.

如何改变这种行为?

NodePort 服务定义如下所示:

NodePort service definition looks like this:

kind: Service
apiVersion: v1
metadata:
  name: kafka-service
spec:
  selector:
    app: cp-kafka
    release: my-confluent-oss
  ports:
    - protocol: TCP
      targetPort: 9092
      port: 32400
      nodePort: 32400
  type: NodePort

Spark 消费者配置:

Spark consumer configuration:

def kafkaParams() = Map[String, Object](
  "bootstrap.servers" -> "192.168.99.100:32400",
  "schema.registry.url" -> "http://192.168.99.100:8081",
  "key.deserializer" -> classOf[StringDeserializer],
  "value.deserializer" -> classOf[KafkaAvroDeserializer],
  "group.id" -> "avro_data",
  "auto.offset.reset" -> "earliest",
  "enable.auto.commit" -> (false: java.lang.Boolean)
)

Kafka生产者配置:

Kafka producer configuration:

  props.put("bootstrap.servers", "192.168.99.100:32400")
  props.put("client.id", "avro_data")
  props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer")
  props.put("value.serializer", "io.confluent.kafka.serializers.KafkaAvroSerializer")
  props.put("schema.registry.url", "http://192.168.99.100:32500")

Kafka 的所有 K8s 服务:

All the K8s services for Kafka:

NAME                                     TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)             AGE
kafka-service                            NodePort       10.99.113.234    <none>        32400:32400/TCP     6m34s
kubernetes                               ClusterIP      10.96.0.1        <none>        443/TCP             27d
my-confluent-oss-cp-kafka                ClusterIP      10.100.156.108   <none>        9092/TCP            102m
my-confluent-oss-cp-kafka-connect        ClusterIP      10.99.78.89      <none>        8083/TCP            102m
my-confluent-oss-cp-kafka-headless       ClusterIP      None             <none>        9092/TCP            102m
my-confluent-oss-cp-kafka-rest           ClusterIP      10.100.152.109   <none>        8082/TCP            102m
my-confluent-oss-cp-ksql-server          ClusterIP      10.96.249.202    <none>        8088/TCP            102m
my-confluent-oss-cp-schema-registry      ClusterIP      10.109.27.45     <none>        8081/TCP            102m
my-confluent-oss-cp-zookeeper            ClusterIP      10.102.182.90    <none>        2181/TCP            102m
my-confluent-oss-cp-zookeeper-headless   ClusterIP      None             <none>        2888/TCP,3888/TCP   102m
schema-registry-service                  NodePort       10.103.100.64    <none>        32500:32500/TCP     33m
zookeeper-np                             NodePort       10.98.180.130    <none>        32181:32181/TCP     53m

推荐答案

当我尝试访问 kafka broker (cp-helm-chart) 从外部运行在 minikube 上.

I had a similar issue when I was trying to access kafka broker (cp-helm-chart) running on minikube from outside.

这是我如何解决它的.在使用 helm install 从本地存储库进行安装之前.

Here how I resolved it. Before you install using helm install from local repository.

1. 在此文件中编辑 https://github.com/confluentinc/cp-helm-charts/blob/master/charts/cp-kafka/values.yaml
2. 搜索 nodeport: 并将其启用字段更改为 true.
   节点端口:
   启用:真
3. 通过删除 #:
   取消对这两行的注释"advertised.listeners": |-
   EXTERNAL://${HOST_IP}:$((31090 + ${KAFKA_BROKER_ID}))
4. 将 ${HOST_IP} 替换为您的 minikube ip(在 cmd 中输入 minikube ip 以检索您的 k8s 主机 ip，例如:196.169.99.100)
5. 将 ${KAFKA_BROKER_ID} 替换为代理 ID(如果只有一个代理正在运行，则默认情况下仅为 0)
6. 最终看起来像这样:
   "advertised.listeners": |-
   外部://196.169.99.100:31090

现在您可以通过将 bootstrap.servers 指向 196.169.99.100:31090 从外部访问在 k8s 集群中运行的 kafka 代理

Now you can access the kafka broker running within k8s cluster from outside by pointing the bootstrap.servers to 196.169.99.100:31090

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