// This module is included in the following assemblies:
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// upgrading/assembly_upgrade-kafka-versions.adoc

[id='con-versions-and-images-{context}']
= Kafka version and image mappings

When upgrading Kafka, consider your settings for the `STRIMZI_KAFKA_IMAGES` environment variable and the `Kafka.spec.kafka.version` property.

* Each `Kafka` resource can be configured with a `Kafka.spec.kafka.version`.
* The Cluster Operator's `STRIMZI_KAFKA_IMAGES` environment variable provides a mapping between the Kafka version and the image to be used when that version is requested in a given `Kafka` resource.
** If `Kafka.spec.kafka.image` is not configured, the default image for the given version is used.
** If `Kafka.spec.kafka.image` is configured, the default image is overridden.

WARNING: The Cluster Operator cannot validate that an image actually contains a Kafka broker of the expected version.
Take care to ensure that the given image corresponds to the given Kafka version.
