How to create Kubernetes objects with Status fields?

Question

I am using the kubernetes operator to create a custom resource in the cluster, the CR has the Status field populated, but when the object gets created the Status field is empty.

This is how I am creating the CR:

reconcile.Create(ctx, &object)

This is what I am trying to accomplish with k8s operator:

Answer 1

The architecture of Kubernetes API and resources follows a pattern.

1. Clients may create resources, by specifying a desired state (This is the spec: part of a resource). This is a "create" request sent to the API Server.

2. Controllers, subscribe/watch to changes of resources, while doing actions in a reconciliation loop, they might update the Status of the resource (this is the status: part of the resource).

For an example of how a controller is implemented and updates the status, see the Kubebuilder book: Implementing a Controller - Update the Status.

The client in the example is a "controller runtime client":

"sigs.k8s.io/controller-runtime/pkg/client"

Example code, where the reconciler updates the status sub-resource:

if err := r.Status().Update(ctx, &cronJob); err != nil {
    log.Error(err, "unable to update CronJob status")
    return ctrl.Result{}, err
}