Hierarchical

Hierarchical namespaces were originally developed by the Workgroup for Multi-Tenancy and introduced in 2020 as a means of better supporting multi-tenancy of a single Kubernetes cluster.

The design implies ownership:

• Policies are inherited from parent namespaces.
• Creation of subnamespaces can be delegated within a parent namespace.

Implementation

• A CRDs within each namespace defines the parent.
• The implementation is provided by the HNC extension. This handles subnamespaces and propagates policy objects.
• The kubectl hns plugin provides an interface for operations folks.