New features:

• PodDisruption budget is configured automatically in order to prevent multiple pods being shut down by k8s
• topologyKey is now configurable. It addresses https://github.com/Altinity/clickhouse-operator/issues/772
• spec.restart: "RollingRestart" attribute has been added in order to initiate graceful restart of a cluster. Use it with a patch command.
• Added a support for Kubernetes secrets in settings section, e.g. for ClickHouse user/password.

Changed:

• Pod maintenance logic during all operations that require pod restart has been improved:
  1. Wait condition is enabled for a pod to be removed from ClickHouse cluster.
  2. Wait condition is added for running queries to complete (up to 5 minutes).
  3. terminationGracePeriod has been increased to 60 seconds.
• Timeout for DDL operations has been increased to 60 seconds. That addresses issues with schema management on slow clusters.
• Base image is switched to RedHat UBI
• ZooKeeper image version has been rolled back to 3.6.1 since we have some problems with 3.6.3
• CRD apiVersion has been upgraded from apiextensions.k8s.io/v1beta1 to apiextensions.k8s.io/v1. The v1beta1 manifests are still available under descriptive names.

Fixed:

• Fixed a bug with non-working custom ports
• Fixed a bug with replicas being incorrectly deleted from ZooKeeper for retained volumes

Note: Upgrade from the previous version will result in restart of ClickHouse clusters.