Components

Mon, 01 Jan 0001 00:00:00 +0000

The Component interface is the central abstraction of the higher-level programming model. It abstracts any custom resource type that describes and models a component in the sense of the terminology: a coherent set of dependent objects that are to be applied to a cluster. A component operator built on top of component-operator-runtime provides one such custom resource type per component, and that type has to implement Component.

The `Component` interface

package component

// Component is the central interface that component operators have to implement.
// Besides being a controller-runtime client.Object, the implementing type has to expose
// accessor methods for the component's spec and status, GetSpec() and GetStatus().
type Component interface {
	client.Object
	// Return a read-only accessor to the component's spec.
	// The returned value has to implement the types.Unstructurable interface.
	GetSpec() types.Unstructurable
	// Return a read-write (usually a pointer) accessor to the component's status,
	// resp. to the corresponding substruct if the status extends component.Status.
	GetStatus() *Status
}

Because the implementing type embeds controller-runtime’s client.Object, it is a regular Kubernetes API type (with TypeMeta and ObjectMeta). On top of that, only two accessor methods have to be provided:

Reconciler

Mon, 01 Jan 0001 00:00:00 +0000

Reconciler[T] is the heart of the higher-level programming model. It implements controller-runtime’s reconcile.Reconciler interface, so it can be plugged into any controller-runtime manager, and it drives a single component type T end to end: it reads the component, resolves its references, renders the dependent objects through a generator, and delegates the actual cluster synchronization to the low-level object reconciler.

A parameterized Go interface

The reconciler is a generic type, parameterized by the component type it manages:

Integration with controller-runtime on Component Operator Runtime

Components

The Component interface

Reconciler

A parameterized Go interface

The `Component` interface