kubernetes - 部署在 Kubernetes 上的 Kafka Producer 无法生产到在本地机器上运行的 Kafka 集群

Question

我在本地机器上运行了一个 Kafka 集群，默认设置在我的 minikube 设置之外。我在其中一个 Web 服务中创建了一个生产者，并将其部署在 minikube 上。

为了让生产者连接到 Kafka，我正在使用 10.0.2.2我还用来在 minikube 之外连接 Cassandra 和 DGraph 的 IP，因为它工作正常。

然而 Kafka 生产者没有工作，甚至没有抛出错误说 Broker may not be available或发送数据时的任何其他错误。但我在消费者方面没有收到任何东西。

当我在 Kubernetes 之外运行这个 Web 服务时，一切正常。

请如果你们知道这里可能有什么问题。

以下是Kubernetes yaml我正在使用的文件。

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: servicename
  labels:
    app: servicename
    metrics: kamon
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: servicename
        metrics: kamon
    spec:
      containers:
      - image: "image:app"
        imagePullPolicy: IfNotPresent
        name: servicename
        env:
        - name: CIRCUIT_BREAKER_MAX_FAILURES
          value: "10"
        - name: CIRCUIT_BREAKER_RESET_TIMEOUT
          value: 30s
        - name: CIRCUIT_BREAKER_CALL_TIMEOUT
          value: 30s
        - name: CONTACT_POINT_ONE
          value: "10.0.2.2"
        - name: DGRAPH_HOSTS
          value: "10.0.2.2"
        - name: DGRAPH_PORT
          value: "9080"
        - name: KAFKA_BOOTSTRAP_SERVERS
          value: "10.0.2.2:9092"
        - name: KAFKA_PRODUCER_NOTIFICATION_CLIENT_ID
          value: "notificationProducer"
        - name: KAFKA_NOTIFICATION_TOPIC
          value: "notification"
        - name: LAGOM_PERSISTENCE_READ_SIDE_OFFSET_TIMEOUT
          value: 5s
        - name: LAGOM_PERSISTENCE_READ_SIDE_FAILURE_EXPONENTIAL_BACKOFF_MIN
          value: 3s
        - name: LAGOM_PERSISTENCE_READ_SIDE_FAILURE_EXPONENTIAL_BACKOFF_MAX
          value: 30s
        - name: LAGOM_PERSISTENCE_READ_SIDE_FAILURE_EXPONENTIAL_BACKOFF_RANDOM_FACTOR
          value: "0.2"
        - name: LAGOM_PERSISTENCE_READ_SIDE_GLOBAL_PREPARE_TIMEOUT
          value: 30s
        - name: LAGOM_PERSISTENCE_READ_SIDE_RUN_ON_ROLE
          value: ""
        - name: LAGOM_PERSISTENCE_READ_SIDE_USE_DISPATCHER
          value: lagom.persistence.dispatcher
        - name: AKKA_TIMEOUT
          value: 30s
        - name: NUMBER_OF_DGRAPH_REPOSITORY_ACTORS
          value: "2"
        - name: DGRAPH_ACTOR_TIMEOUT_MILLIS
          value: "20000"
        - name: AKKA_ACTOR_PROVIDER
          value: "cluster"
        - name: AKKA_CLUSTER_SHUTDOWN_AFTER_UNSUCCESSFUL_JOIN_SEED_NODES
          value: 40s
        - name: AKKA_DISCOVERY_METHOD
          value: "kubernetes-api"
        - name: AKKA_IO_DNS_RESOLVER
          value: "async-dns"
        - name: AKKA_IO_DNS_ASYNC_DNS_PROVIDER_OBJECT
          value: "com.lightbend.rp.asyncdns.AsyncDnsProvider"
        - name: AKKA_IO_DNS_ASYNC_DNS_RESOLVE_SRV
          value: "true"
        - name: AKKA_IO_DNS_ASYNC_DNS_RESOLV_CONF
          value: "on"
        - name: AKKA_MANAGEMENT_HTTP_PORT
          value: "10002"
        - name: AKKA_MANAGEMENT_HTTP_BIND_HOSTNAME
          value: "0.0.0.0"
        - name: AKKA_MANAGEMENT_HTTP_BIND_PORT
          value: "10002"
        - name: AKKA_MANAGEMENT_CLUSTER_BOOTSTRAP_CONTACT_POINT_DISCOVERY_REQUIRED_CONTACT_POINT_NR
          value: "1"
        - name: AKKA_REMOTE_NETTY_TCP_PORT
          value: "10001"
        - name: AKKA_REMOTE_NETTY_TCP_BIND_HOSTNAME
          value: "0.0.0.0"
        - name: AKKA_REMOTE_NETTY_TCP_BIND_HOSTNAME
          value: "0.0.0.0"
        - name: AKKA_REMOTE_NETTY_TCP_BIND_PORT
          value: "10001"
        - name: LAGOM_CLUSTER_EXIT_JVM_WHEN_SYSTEM_TERMINATED
          value: "on"
        - name: PLAY_SERVER_HTTP_ADDRESS
          value: "0.0.0.0"
        - name: PLAY_SERVER_HTTP_PORT
          value: "9000"
        ports:
        - containerPort: 9000
        - containerPort: 9095
        - containerPort: 10001
        - containerPort: 9092
          name: "akka-remote"
        - containerPort: 10002
          name: "akka-mgmt-http"
---
apiVersion: v1
kind: Service
metadata:
  name: servicename
  labels:
    app: servicename
spec:
  ports:
    - name: "http"
      port: 9000
      nodePort: 31001
      targetPort: 9000
    - name: "akka-remote"
      port: 10001
      protocol: TCP
      targetPort: 10001
    - name: "akka-mgmt-http"
      port: 10002
      protocol: TCP
      targetPort: 10002
  selector:
    app: servicename
  type: NodePort

Answer 1

I am already connecting to Cassandra and Dgraph running on the same machine as Kafka

好吧，这些服务不会通过 Zookeeper 公布他们的网络地址。

My Kafka cluster is outside the K8. However, the producer is in K8.

为了让 k8s 之外的服务知道 Kafka 的位置， advertised.listeners需要设置为 k8s 环境中的所有生产者/消费者服务都将识别的外部 IP 或 DNS 地址，这就是您的服务将连接到的地址。例如 PLAINTEXT://10.0.2.2:9092
换句话说，如果你没有设置监听器，它只是在 localhost 上监听，仅仅因为 Kafka 端口是外部暴露的，这意味着虽然你可以访问一个代理，但你返回的地址是该协议(protocol)不能保证与您的客户端配置相同，这就是广告监听器地址发挥作用的地方。