Avoidable(?) error message after changing log format to JSON?

[psheichelberg]

I have changed the log format of my kafka.kafka.strimzi.io with this configuration:

spec:
  kafka:
    logging:
      type: inline
      loggers:
        appender.console.layout.type: JsonTemplateLayout
        appender.console.layout.eventTemplate: […] # omited, see https://github.com/apache/logging-log4j2/blob/rel/2.25.3/log4j-layout-template-json/src/main/resources/LogstashJsonEventLayoutV1.json 

This works fine (except for a few log lines at startup that are probably printed by kafka_run.sh.

But now I have an error message in my logs:

2026-02-17T08:30:44.370423732Z main ERROR JsonTemplateLayout contains an invalid element or attribute "pattern"

I suspect the reason is that the appender.console.layout.pattern is still present:

apiVersion: v1
kind: ConfigMap
data:
  cluster.id: gbZ8TcatQ6SYatEUQp4LCg
  log4j2.properties: |
    # Do not change this generated file. Logging can be configured in the corresponding Kubernetes resource.
    name=KafkaConfig
    appender.console.type=Console
    appender.console.name=STDOUT
    appender.console.layout.type=JsonTemplateLayout
    appender.console.layout.pattern=%d{yyyy-MM-dd HH:mm:ss} %-5p [%t] %c{1}:%L - %m%n
    […]
    appender.console.layout.eventTemplate=[…]

Is there any way to unset/remove the appender.console.layout.pattern line? I would like to not have ERROR messages in my logs when they are not actually errors. 😅

Thank you in advance!

[psheichelberg]

I tried nil, null and "" but it did not help:

spec:
  kafka:
    logging:
      loggers:
        appender.console.layout.pattern: nil
        appender.console.layout.pattern: null
        appender.console.layout.pattern: ""

[scholzj]

The inline configuration is designed for simple changes such as log levels etc. For more complex changes such as using custom layout, you should use the external logging configuration.

[psheichelberg]

Thanks, that worked!

[…]
spec:
  kafka:
    logging:
      type: external
      valueFrom:
        configMapKeyRef:
          name: kafka-logging
          key: log4j2.properties
[…]
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: kafka-logging
data:
  log4j2.properties: |-
[…]