feat: support keeper on a different namespace

[ertanden]

Why

ClickHouse clusters currently can only reference a Keeper cluster in the same namespace. This change is needed to allow deploying Keeper in a different namespace while keeping the existing same-namespace behavior working by default.

What

This change replaces keeperClusterRef with a small custom reference type that includes name and optional namespace. The ClickHouse controller now resolves Keeper by namespace and name, cross-namespace Keeper updates can requeue dependent ClickHouse clusters, and the CRD/docs/tests were updated to reflect the new reference format.

crd-breaking-change - suppress check, because keeperRef.name became required, which is not a breaking change as it was validated in the webhook before.

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull request overview

Adds cross-namespace Keeper support by replacing keeperClusterRef with a custom reference type (name + optional namespace) and updating reconciliation + watches so Keeper changes can requeue dependent ClickHouse clusters across namespaces.

Changes:

• Introduce KeeperClusterReference and resolution helpers, update controller to resolve Keeper by fully-qualified namespaced name.
• Add a field index + watch mapping so Keeper updates enqueue referencing ClickHouse clusters (including cross-namespace references).
• Update CRD/schema, docs, and tests to use/describe the new reference format and validate keeperClusterRef.namespace.

Reviewed changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
test/e2e/clickhouse_e2e_test.go	Updates e2e specs to use KeeperClusterReference.
test/deploy/deploy_test.go	Updates deployment test manifests to use KeeperClusterReference.
internal/webhook/v1alpha1/clickhousecluster_webhook_test.go	Adds webhook tests for valid/invalid keeper namespace.
internal/webhook/v1alpha1/clickhousecluster_webhook.go	Validates keeperClusterRef.namespace as DNS1123 label when set.
internal/controller/clickhouse/sync.go	Resolves Keeper using Cluster.KeeperClusterNamespacedName() and improves log/error context.
internal/controller/clickhouse/controller_test.go	Adds tests for cross-namespace keeper watch mapping + reconciliation behavior.
internal/controller/clickhouse/controller.go	Adds field indexer for keeper reference; watch mapping lists clusters via indexed field to support cross-namespace.
docs/introduction.md	Documents default same-namespace behavior and optional keeperClusterRef.namespace.
docs/configuration.md	Documents new keeperClusterRef.namespace and watch-namespace requirement.
docs/api_reference.md	Updates API reference to document KeeperClusterReference.
dist/chart/templates/crd/clickhouseclusters.clickhouse.com.yaml	Updates CRD schema for new keeper reference type.
config/crd/bases/clickhouse.com_clickhouseclusters.yaml	Updates CRD base schema for new keeper reference type.
api/v1alpha1/zz_generated.deepcopy.go	Regenerates deepcopy for the new reference type.
api/v1alpha1/types_test.go	Adds unit tests for keeper namespaced name resolution defaulting.
api/v1alpha1/clickhousecluster_types.go	Introduces KeeperClusterReference and resolution helpers on the API types.

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[ertanden]

Thanks for merging. Is there a timeline for a new version release?