cp-kafka-rest in Kubernetes exits with error

1. Starting Kafka Rest Proxy in Kubernetes exits with

   $ kubectl logs -f kafka-rest-lr991

   + [[ -n tcp://10.0.0.95:8082 ]]
  + echo 'PORT is deprecated. Please use KAFKA_REST_LISTENERS instead.'
  + exit 1

  PORT is deprecated. Please use KAFKA_REST_LISTENERS instead.

1. Environment

   • Zookeeper deployed into Kubernetes cluster using image from - https://hub.docker.com/r/elevy/zookeeper/
   • Kafka deployed into Kubernetes cluster using image from - https://hub.docker.com/r/cloudtrackinc/kubernetes-kafka/
   • Kafka REST Proxy deployed into Kubernetes cluster using image from - https://hub.docker.com/r/confluentinc/cp-kafka-rest/

2. Followed this thread in Stackoverflow (https://stackoverflow.com/questions/41868161/kafka-in-kubernetes-cluster-how-to-publish-consume-messages-from-outside-of-kub/41869856).

3. Following “kaka-rest-controller.yaml” file is used to start the pod in Kubernetes with required ENV variables

------------kaka-rest-controller.yaml-----------------
apiVersion: v1
kind: ReplicationController
metadata:
  labels:
    app: kafka-rest
    component: kafka-rest-endpoint
  name: kafka-rest
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: kafka-rest
        component: kafka-rest-endpoint
    spec:
      containers:
      - name: kafka-rest
        image: confluentinc/cp-kafka-rest:3.2.2
        env:
          - name: KAFKA_REST_HOST_NAME
            valueFrom:
              fieldRef:
                fieldPath: status.podIP
          - name: KAFKA_REST_ZOOKEEPER_CONNECT
            value: zookeeper:2181

Not sure if there are additional environmental variables missing, By default the Docker image seem to set the PORT by default and seem to check for it to exit.

Any help is appreciated

[geofflamrock]

Do you have a Kubernetes service called kafka-rest in your setup?

Environment variables are added by Kubernetes for services by default, and I found that I had to name the service something else like kafka-rest-service for it to not find that environment variable and continue on.

[bojidar-bg]

I managed to workaround this issue without renaming the service by unsetting the environment variable before running:

apiVersion: apps/v1
kind: StatefulSet
spec:
  # ...
  template:
    # ...
    spec:
      containers:
      - image: confluentinc/cp-kafka-rest:5.0.1
        # ...
        command: ["bash", "-c", "unset KAFKA_REST_PORT; /etc/confluent/docker/run"]