I have a Kafka created by Strimzi at hm-kafka-kafka-bootstrap.hm-kafka.svc:9092.

I am trying to install Confluent Schema Registry using Bitnami helm at https://github.com/bitnami/charts/tree/main/bitnami/schema-registry

Here are my steps:

helm upgrade \
  confluent-schema-registry \
  oci://registry-1.docker.io/bitnamicharts/schema-registry \
  --install \
  --namespace=hm-confluent-schema-registry \
  --create-namespace \
  --values=my-values.yaml

my-values.yaml:

kafka:
  enabled: false
externalKafka:
  brokers:
    - PLAINTEXT://hm-kafka-kafka-bootstrap.hm-kafka.svc:9092

However, this gives me error

Error: template: schema-registry/templates/statefulset.yaml:4:95: executing "schema-registry/templates/statefulset.yaml" at <.Values.kafka.auth.clientProtocol>: nil pointer evaluating interface {}.clientProtocol

Any idea? Thanks!

TL;DR

Assume the Kafka is at hm-kafka-kafka-bootstrap.hm-kafka.svc:9092, Confluent Schema Registry can be installed by

helm upgrade \
  confluent-schema-registry \
  oci://registry-1.docker.io/bitnamicharts/schema-registry \
  --install \
  --namespace=hm-confluent-schema-registry \
  --create-namespace \
  --values=my-values.yaml

my-values.yaml:

kafka:
  enabled: false
  auth:
    protocol: {}
  service:
    ports:
      client: {}
externalKafka:
  brokers:
    - PLAINTEXT://hm-kafka-kafka-bootstrap.hm-kafka.svc:9092

---

How I found out

Attempt 2 (Failed)

I did further experiments based on the error I got in my question, I updated to

my-values.yaml:

kafka:
  enabled: false
  auth:
    protocol: plaintext
externalKafka:
  brokers:
    - PLAINTEXT://hm-kafka-kafka-bootstrap.hm-kafka.svc:9092

gives me error

Error: template: schema-registry/templates/statefulset.yaml:7:29: executing "schema-registry/templates/statefulset.yaml" at <.Values.kafka.service.ports.client>: nil pointer evaluating interface {}.ports

Attempt 3 (Succeed)

my-values.yaml:

kafka:
  enabled: false
  auth:
    protocol: plaintext
  service:
    ports:
      client: 9092
externalKafka:
  brokers:
    - PLAINTEXT://hm-kafka-kafka-bootstrap.hm-kafka.svc:9092

Now I can see default _schemas from Confluent Schema Registry got created with some messages inside:

The issue is that these two parameters currently do not exist in schema-registry/values.yaml:

kafka:
  auth:
    protocol: plaintext
  service:
    ports:
      client: 9092

I have reported the issue at https://github.com/bitnami/charts/issues/17126

---

UPDATE

@wackazong pointed out can simply use

kafka:
  enabled: false
  auth:
    protocol: {}
  service:
    ports:
      client: {}
externalKafka:
  brokers:
    - PLAINTEXT://hm-kafka-kafka-bootstrap.hm-kafka.svc:9092

Confirmed it works. Thanks!