从集群外部在kubernetes上聆听kafak

时间:2019-07-16 23:33:21

标签: kubernetes apache-kafka google-kubernetes-engine kafka-python

我正在Google云平台上运行kubernetes集群,并使用Helm图表在其上安装了kafka(https://hub.kubeapps.com/charts/bitnami/kafka)。我也有另一个部署运行python pod。我已经使用LoadBalancers公开了kafka和zookeper。这是我运行kubectl get all时得到的(IP地址已更改)

kubectl get all

NAME                                    READY   STATUS    RESTARTS   AGE
pod/my-kafka-0                          1/1     Running   1          3h2m
pod/my-kafka-zookeepe-0                 1/1     Running   0          3h2m
pod/my-python-6c746645f5-5xvsb          1/1     Running   0          34m

NAME                                        TYPE           CLUSTER-IP    EXTERNAL-IP     PORT(S)                                        AGE
service/kubernetes                          ClusterIP      10.10.0.1     <none>          443/TCP                                        3h16m
service/my-kafka                            LoadBalancer   10.10.0.110   35.35.135.150   9092:30769/TCP                                 3h2m
service/my-kafka-headless                   ClusterIP      None          <none>          9092/TCP                                       3h2m
service/my-kafka-zookeepe                   LoadBalancer   10.10.0.45    35.35.135.160   2181:32740/TCP,2888:31095/TCP,3888:30057/TCP   3h2m
service/my-kafka-zookeepe-headless          ClusterIP      None          <none>          2181/TCP,2888/TCP,3888/TCP                     3h2m
service/my-python                           ClusterIP      10.10.10.80   <none>          9999/TCP                                       171m

NAME                              DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/my-python         1         1         1            1           136m

NAME                                         DESIRED   CURRENT   READY   AGE
replicaset.apps/my-python-6c746645f5         1         1         1       35m
replicaset.apps/my-python-848f769cd          0         0         0       136m

NAME                                        DESIRED   CURRENT   AGE
statefulset.apps/my-kafka                   1         1         3h2m
statefulset.apps/my-kafka-zookeepe          1         1         3h2m

如果我打开python pod的终端,则可以访问kafka服务。我可以使用python创建主题,创建生产者和消费者,并且可以正常工作。以下是我用来测试的代码段。

kubectl exec -it my-python-6c746645f5-5xvsb /bin/bash
from kafka.admin import KafkaAdminClient, NewTopic
admin_client = KafkaAdminClient(bootstrap_servers="my-kafka-headless.default.svc.cluster.local:9092", client_id='test')

topic_list = []
topic_list.append(NewTopic(name="test-topic", num_partitions=1, replication_factor=1))
admin_client.create_topics(new_topics=topic_list, validate_only=False)
from kafka import KafkaProducer

producer = KafkaProducer(bootstrap_servers='my-kafka-headless.default.svc.cluster.local:9092')

producer.send('test-topic', b'message')
from kafka import KafkaConsumer

while True:

    consumer = KafkaConsumer('test-topic',
                            bootstrap_servers='my-kafka-headless.default.svc.cluster.local:9092')
    for msg in consumer:
        print (msg)

从kafka配置yaml文件中找到引导服务器的值。

- name: KAFKA_CFG_ADVERTISED_LISTENERS
  value: PLAINTEXT://$(MY_POD_NAME).my-kafka-headless.default.svc.cluster.local:$(KAFKA_PORT_NUMBER)

到目前为止,一切似乎都正常。现在,如果我尝试使用外部IP从外部访问kafka代理,它似乎不起作用。我可以使用以下内容查看主题。

c= kafka.KafkaConsumer(bootstrap_servers=["35.35.135.150:9092"])
c.topics()
set([test-topic'])

但是,使用以下内容我看不到任何消息。

from kafka import KafkaConsumer

while True:

    consumer = KafkaConsumer('test-topic',
                            bootstrap_servers=["35.35.135.150:9092"])
    for msg in consumer:
        print (msg)

我也没有任何错误。我似乎无法弄清楚我在做什么错。

1 个答案:

答案 0 :(得分:2)

感谢cricket_007的评论,我得以解决此问题。我修改了配置文件,以将外部端点包括为公告的侦听器,并将内部服务名称移到了侦听器。

- name: KAFKA_CFG_LISTENERS
  value: PLAINTEXT://$(MY_POD_NAME).my-kafka-headless.default.svc.cluster.local:$(KAFKA_PORT_NUMBER)
- name: KAFKA_CFG_ADVERTISED_LISTENERS
  value: PLAINTEXT://35.35.135.150:9092