AKS ExternalName usage to expose to another namespace

[ghost]

Hi guys,

In my AKS cluster I have a few microservices in one namespace and a Kafka cluster on a separate one.
I can communicate with Kafka bootstrap service with cluster-ip (nodePort) this ensures that ip address does not change?
I want a better approach, using a domain name and I try the follow:

kind: Service
apiVersion: v1
metadata:
  name: my-kafka-cluster-kafka-bootstrap
  namespace: kafka
spec:
  type: ExternalName
  externalName: kafka-bootstrap-external

but I can’t communicate with bootstrap when I use externalName "kafka-bootstrap-external", I notice that cluster-ip changed to none when I apply that yaml file.

How can I solve this problem?

Thanks :)

[scholzj]

You should use internal listener when you want to use the Kafka cluster from applications running in the same Kafka cluster.

[ghost]

Sorry I’m new with Kafka and K8S can you please be more detailed.
My microservice can produce messages to Kafka when i use cluster ip but when i apply that yml file and try to use "kafka-bootstrap-external" as my external ip I cant connect with cluster.
When both services are in same namespace works like charm using service name "my-kafka-cluster-kafka-bootstrap".
The problem is when a microservice are in namespace A and Kafka in namespace B.

[scholzj]

Strimzi lets you configure different listener types -> for access from the same Kubernetes cluster, you should use the internal type service. The docs and the example files have many examples of it. Make sure to use the address with the serrvice at the end if you connect from other namespace and make sure that you do not use any networking which would not allow communication between namespaces (you probably don't have that if ClusterIP works).

[ghost]

I could acess via DNS using ..svc.cluster.local:9092