✨ Cluster registry - an extention that allows you to track connected cluster names

[m-szalik]

What

• An extension to track connected cluster names.
• An usage example.

Why
If you want to synchronize resource between clusters you need to connect to each cluster and create/update or delete the
resource on each cluster. To be able to get k8s client for the cluster you need to know it's name.
This extension allows you to get list of names of connected clusters.

Changes
Extension added.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: m-szalik / name: Marek Szalik (0e2c2e9, a002c37)

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[ntnn]

Theres already clusters.Clusters which basically has the ClusterNames functionality.

Maybe add a clusters.Registry in pkg/clusters like this:

type Registry struct {
	Clusters
}

func (r *Registry) Engage(ctx context.Context, name string, cl cluster.Cluster) error {
	return cr.Add(ctx, name, cl, nil)
}

And adjust the example for clusters.Registry. Less overhead overall.

Edit: Might be better to not reuse Clusters now that I think about it, it will try to start the cluster and depending on the implementation that could error.
Regardless of that I think clusters.Registry would be preferable.