Managed Resources on Crossplane

Managed Resources

A managed resource (MR) represents an external service in a Provider. When users create a new managed resource, the Provider reacts by creating an external resource inside the Provider’s environment. Every external service managed by Crossplane maps to a managed resource.

Note

Crossplane calls the object inside Kubernetes a managed resource and the external object inside the Provider an external resource.

Examples of managed resources include:

Managed Resource Definitions

Important

Crossplane v2.0+ enables managed resource definitions by default. This automatically converts provider CRDs to MRDs during installation. To disable this behavior, set --enable-custom-to-managed-resource-conversion=false when installing Crossplane.

A ManagedResourceDefinition (MRD) is a lightweight abstraction over Kubernetes CustomResourceDefinitions (CRDs) that enables selective activation of managed resources. MRDs solve the problem of providers installing hundreds of CRDs when you only need one or two, reducing API server overhead and improving cluster performance.

Managed Resource Activation Policies

Important

Managed resource activation policies work with managed resource definitions, which Crossplane v2.0+ enables by default. To disable this behavior, set --enable-custom-to-managed-resource-conversion=false when installing Crossplane.

A ManagedResourceActivationPolicy (MRAP) controls which ManagedResourceDefinitions become active in your cluster. MRAPs enable selective installation of provider resources, allowing you to activate only the 10 managed resources you need instead of the 100+ that a provider ships.

The selective activation problem

Modern Crossplane providers can ship dozens or hundreds of managed resources, but most users only need a small subset. Before MRAPs, you got “all or nothing” - installing a provider meant getting every managed resource it supported, consuming unnecessary cluster resources.

Usages

A Usage indicates a resource is in use. Two main use cases for Usages are as follows:

Protecting a resource from accidental deletion.
Deletion ordering by ensuring that a resource isn’t deleted before the deletion of its dependent resources.

See the section Usage for Deletion Protection for the first use case and the section Usage for Deletion Ordering for the second one.

Enable usages

Usages are a beta feature. Crossplane enables beta features by default.