[ANNOUNCE] [RELEASE] Strimzi Kafka Operators 0.21.0 released

Jakub Scholz

Strimzi Operators 0.21.0 is now available with a lot of important changes and improvements. The main changes since the 0.20.0 release include:
* Add support for Kafka 2.7.0
* Add support for declarative management of connector plugins in Kafka Connect CR 
* Add `inter.broker.protocol.version` to the default configuration in example YAMLs
* Add support for `secretPrefix` property for User Operator to prefix all secret names created from KafkaUser resource.
* Allow configuring labels and annotations for Cluster CA certificate secrets
* Add the JAAS configuration string in the sasl.jaas.config property to the generated secrets for KafkaUser with SCRAM-SHA-512 authentication.
* Strimzi `test-container` has been renamed to `strimzi-test-container` to make the name more clear
* Updated the CPU usage metric in the Kafka, ZooKeeper and Cruise Control dashboards to include the CPU kernel time (other than the current user time)
* Allow disabling ownerReference on CA secrets
* Make it possible to run Strimzi operators and operands with read-only root filesystem
* Move from Docker Hub to Quay.io as our container registry
* Add possibility to configure DeploymentStrategy for Kafka Connect, Kafka Mirror Maker (1 and 2), and Kafka Bridge
* Support passing metrics configuration as an external ConfigMap
* Enable CORS configuration for Cruise Control
* Add support for rolling individual Kafka or ZooKeeper pods through the Cluster Operator using an annotation
* Add support for Topology Spread Constraints in Pod templates
* Make Kafka `cluster-id` (KIP-78) available on Kafka CRD status

There are also some deprecations you should be aware of:
* The `metrics` field in the Strimzi custom resources has been deprecated and will be removed in the future. For configuring metrics, use the new `metricsConfig` field and pass the configuration via ConfigMap.

Since 0.21.0 Strimzi supports Kubernetes version 1.16 and newer.

For more details and installation files, go to https://github.com/strimzi/strimzi-kafka-operator/releases/tag/0.21.0

Many thanks to everyone who contributed to this release!

Thanks & Regards
Strimzi team