Chapter 5. KafkaClusterSpec schema reference Used in: KafkaSpec Full list of KafkaClusterSpec schema properties Configures a Kafka cluster using the Kafka custom resource. The config properties are one part of the overall configuration for the resource. Use the config properties to configure Kafka broker options as keys. Example Kafka configuration apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka metadata: name: my-cluster spec: kafka: version: 3.9.0 metadataVersion: 3.9 # ... config: auto.create.topics.enable: "false" offsets.topic.replication.factor: 3 transaction.state.log.replication.factor: 3 transaction.state.log.min.isr: 2 default.replication.factor: 3 min.insync.replicas: 2 # ... The values can be one of the following JSON types: String Number Boolean Exceptions You can specify and configure the options listed in the Apache Kafka documentation . However, Streams for Apache Kafka takes care of configuring and managing options related to the following, which cannot be changed: Security (encryption, authentication, and authorization) Listener configuration Broker ID configuration Configuration of log data directories Inter-broker communication ZooKeeper connectivity Properties with the following prefixes cannot be set: advertised. authorizer. broker. controller cruise.control.metrics.reporter.bootstrap. cruise.control.metrics.topic host.name inter.broker.listener.name listener. listeners. log.dir password. port process.roles sasl. security. servers,node.id ssl. super.user zookeeper.clientCnxnSocket zookeeper.connect zookeeper.set.acl zookeeper.ssl If the config property contains an option that cannot be changed, it is disregarded, and a warning message is logged to the Cluster Operator log file. All other supported options are forwarded to Kafka, including the following exceptions to the options configured by Streams for Apache Kafka: Any ssl configuration for supported TLS versions and cipher suites Configuration for the zookeeper.connection.timeout.ms property to set the maximum time allowed for establishing a ZooKeeper connection Cruise Control metrics properties: cruise.control.metrics.topic.num.partitions cruise.control.metrics.topic.replication.factor cruise.control.metrics.topic.retention.ms cruise.control.metrics.topic.auto.create.retries cruise.control.metrics.topic.auto.create.timeout.ms cruise.control.metrics.topic.min.insync.replicas Controller properties: controller.quorum.election.backoff.max.ms controller.quorum.election.timeout.ms controller.quorum.fetch.timeout.ms 5.1. Configuring rack awareness and init container images Rack awareness is enabled using the rack property. When rack awareness is enabled, Kafka broker pods use init container to collect the labels from the OpenShift cluster nodes. The container image for this init container can be specified using the brokerRackInitImage property. If the brokerRackInitImage field is not provided, the images used are prioritized as follows: Container image specified in STRIMZI_DEFAULT_KAFKA_INIT_IMAGE environment variable in the Cluster Operator configuration. registry.redhat.io/amq-streams/strimzi-rhel9-operator:2.9.0 container image. Example brokerRackInitImage configuration apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka metadata: name: my-cluster spec: kafka: # ... rack: topologyKey: topology.kubernetes.io/zone brokerRackInitImage: my-org/my-image:latest # ... Note Overriding container images is recommended only in special situations, such as when your network does not allow access to the container registry used by Streams for Apache Kafka. In such cases, you should either copy the Streams for Apache Kafka images or build them from the source. Be aware that if the configured image is not compatible with Streams for Apache Kafka images, it might not work properly. 5.2. Logging Kafka has its own configurable loggers, which include the following: log4j.logger.org.apache.zookeeper log4j.logger.kafka log4j.logger.org.apache.kafka log4j.logger.kafka.request.logger log4j.logger.kafka.network.Processor log4j.logger.kafka.server.KafkaApis log4j.logger.kafka.network.RequestChannelUSD log4j.logger.kafka.controller log4j.logger.kafka.log.LogCleaner log4j.logger.state.change.logger log4j.logger.kafka.authorizer.logger Kafka uses the Apache log4j logger implementation. Use the logging property to configure loggers and logger levels. You can set the log levels by specifying the logger and level directly (inline) or use a custom (external) ConfigMap. If a ConfigMap is used, you set logging.valueFrom.configMapKeyRef.name property to the name of the ConfigMap containing the external logging configuration. Inside the ConfigMap, the logging configuration is described using log4j.properties . Both logging.valueFrom.configMapKeyRef.name and logging.valueFrom.configMapKeyRef.key properties are mandatory. A ConfigMap using the exact logging configuration specified is created with the custom resource when the Cluster Operator is running, then recreated after each reconciliation. If you do not specify a custom ConfigMap, default logging settings are used. If a specific logger value is not set, upper-level logger settings are inherited for that logger. For more information about log levels, see Apache logging services . Here we see examples of inline and external logging. The inline logging specifies the root logger level. You can also set log levels for specific classes or loggers by adding them to the loggers property. Inline logging apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka spec: # ... kafka: # ... logging: type: inline loggers: kafka.root.logger.level: INFO log4j.logger.kafka.coordinator.transaction: TRACE log4j.logger.kafka.log.LogCleanerManager: DEBUG log4j.logger.kafka.request.logger: DEBUG log4j.logger.io.strimzi.kafka.oauth: DEBUG log4j.logger.org.openpolicyagents.kafka.OpaAuthorizer: DEBUG # ... Note Setting a log level to DEBUG may result in a large amount of log output and may have performance implications. External logging apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka spec: # ... logging: type: external valueFrom: configMapKeyRef: name: customConfigMap key: kafka-log4j.properties # ... Any available loggers that are not configured have their level set to OFF . If Kafka was deployed using the Cluster Operator, changes to Kafka logging levels are applied dynamically. If you use external logging, a rolling update is triggered when logging appenders are changed. Garbage collector (GC) Garbage collector logging can also be enabled (or disabled) using the jvmOptions property . 5.3. KafkaClusterSpec schema properties Property Property type Description version string The Kafka broker version. Defaults to the latest version. Consult the user documentation to understand the process required to upgrade or downgrade the version. metadataVersion string Added in Streams for Apache Kafka 2.7. The KRaft metadata version used by the Kafka cluster. This property is ignored when running in ZooKeeper mode. If the property is not set, it defaults to the metadata version that corresponds to the version property. replicas integer The number of pods in the cluster. This property is required when node pools are not used. image string The container image used for Kafka pods. If the property is not set, the default Kafka image version is determined based on the version configuration. The image names are specifically mapped to corresponding versions in the Cluster Operator configuration. Changing the Kafka image version does not automatically update the image versions for other components, such as Kafka Exporter. listeners GenericKafkaListener array Configures listeners to provide access to Kafka brokers. config map Kafka broker config properties with the following prefixes cannot be set: listeners, advertised., broker., listener., host.name, port, inter.broker.listener.name, sasl., ssl., security., password., log.dir, zookeeper.connect, zookeeper.set.acl, zookeeper.ssl, zookeeper.clientCnxnSocket, authorizer., super.user, cruise.control.metrics.topic, cruise.control.metrics.reporter.bootstrap.servers, node.id, process.roles, controller., metadata.log.dir, zookeeper.metadata.migration.enable, client.quota.callback.static.kafka.admin., client.quota.callback.static.produce, client.quota.callback.static.fetch, client.quota.callback.static.storage.per.volume.limit.min.available., client.quota.callback.static.excluded.principal.name.list (with the exception of: zookeeper.connection.timeout.ms, sasl.server.max.receive.size, ssl.cipher.suites, ssl.protocol, ssl.enabled.protocols, ssl.secure.random.implementation, cruise.control.metrics.topic.num.partitions, cruise.control.metrics.topic.replication.factor, cruise.control.metrics.topic.retention.ms, cruise.control.metrics.topic.auto.create.retries, cruise.control.metrics.topic.auto.create.timeout.ms, cruise.control.metrics.topic.min.insync.replicas, controller.quorum.election.backoff.max.ms, controller.quorum.election.timeout.ms, controller.quorum.fetch.timeout.ms). storage EphemeralStorage , PersistentClaimStorage , JbodStorage Storage configuration (disk). Cannot be updated. This property is required when node pools are not used. authorization KafkaAuthorizationSimple , KafkaAuthorizationOpa , KafkaAuthorizationKeycloak , KafkaAuthorizationCustom Authorization configuration for Kafka brokers. rack Rack Configuration of the broker.rack broker config. brokerRackInitImage string The image of the init container used for initializing the broker.rack . livenessProbe Probe Pod liveness checking. readinessProbe Probe Pod readiness checking. jvmOptions JvmOptions JVM Options for pods. jmxOptions KafkaJmxOptions JMX Options for Kafka brokers. resources ResourceRequirements CPU and memory resources to reserve. metricsConfig JmxPrometheusExporterMetrics Metrics configuration. logging InlineLogging , ExternalLogging Logging configuration for Kafka. template KafkaClusterTemplate Template for Kafka cluster resources. The template allows users to specify how the OpenShift resources are generated. tieredStorage TieredStorageCustom Configure the tiered storage feature for Kafka brokers. quotas QuotasPluginKafka , QuotasPluginStrimzi Quotas plugin configuration for Kafka brokers allows setting quotas for disk usage, produce/fetch rates, and more. Supported plugin types include kafka (default) and strimzi . If not specified, the default kafka quotas plugin is used.

Commands:
apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka metadata: name: my-cluster spec: kafka: version: 3.9.0 metadataVersion: 3.9 # config: auto.create.topics.enable: "false" offsets.topic.replication.factor: 3 transaction.state.log.replication.factor: 3 transaction.state.log.min.isr: 2 default.replication.factor: 3 min.insync.replicas: 2
apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka metadata: name: my-cluster spec: kafka: # rack: topologyKey: topology.kubernetes.io/zone brokerRackInitImage: my-org/my-image:latest #
apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka spec: # kafka: # logging: type: inline loggers: kafka.root.logger.level: INFO log4j.logger.kafka.coordinator.transaction: TRACE log4j.logger.kafka.log.LogCleanerManager: DEBUG log4j.logger.kafka.request.logger: DEBUG log4j.logger.io.strimzi.kafka.oauth: DEBUG log4j.logger.org.openpolicyagents.kafka.OpaAuthorizer: DEBUG #
apiVersion: kafka.strimzi.io/v1beta2 kind: Kafka spec: # logging: type: external valueFrom: configMapKeyRef: name: customConfigMap key: kafka-log4j.properties #