How to expose a headless service for a StatefulSet externally in Kubernetes

Question

Using kubernetes-kafka as a starting point with minikube.

This uses a StatefulSet and a headless service for service discovery within the cluster.

The goal i

Answer 1

From the kubernetes kafka documentation:

Outside access with hostport

An alternative is to use the hostport for the outside access. When using this only one kafka broker can run on each host, which is a good idea anyway.

In order to switch to hostport the kafka advertise address needs to be switched to the ExternalIP or ExternalDNS name of the node running the broker. in kafka/10broker-config.yml switch to

OUTSIDE_HOST=$(kubectl get node "$NODE_NAME" -o jsonpath='{.status.addresses[?(@.type=="ExternalIP")].address}')
OUTSIDE_PORT=${OutsidePort}

and in kafka/50kafka.yml add the hostport:

    - name: outside
      containerPort: 9094
      hostPort: 9094