Make lables configureable

[maximiliantech]

Description

When using the service-provider-crossplane, we call code from this repository's Juggler package.

Currently, we have the issue that the word control-plane-operator will be still attached as label to FluxComponents such as HelmRepository and HelmRelease resources, see

Expected behaviour

It is expected that the label app.kubernetes.io/managed-by=service-provider-crossplane would be applied.

Root cause analysis

This issue originates from this line of code...

control-plane-operator/pkg/juggler/fluxcd/flux_reconciler.go

Lines 218 to 219 in e0442e0

	utils.SetManagedBy(obj)
	utils.SetLabel(obj, r.labelComponentName, fluxComponent.GetName())

... where the Juggler statically calls these constants as part of the func SetManagedBy(obj v1.Object):

control-plane-operator/pkg/utils/meta.go

Lines 8 to 25 in e0442e0

	const (
	labelManagedBy = "app.kubernetes.io/managed-by"
	labelManagedByValue = "control-plane-operator"
	LabelComponentName = "controlplane.core.orchestrate.cloud.sap/component"
	)
	func SetLabel(obj v1.Object, label string, value string) {
	labels := obj.GetLabels()
	if labels == nil {
	labels = map[string]string{}
	}
	labels[label] = value
	obj.SetLabels(labels)
	}
	func SetManagedBy(obj v1.Object) {
	SetLabel(obj, labelManagedBy, labelManagedByValue)
	}

With #101, there was already the attempt to refactor this code to make it more configurable, but not all occurrences of labels where covered with e5abe40.

Solution proposal

Let's pass down a func ...(...) error that will be executed during the CreateOrUpdate, so that you can make the applied labels configureable.

control-plane-operator/pkg/juggler/fluxcd/flux_reconciler.go

Lines 213 to 221 in e0442e0

	result, errCU := controllerutil.CreateOrUpdate(ctx, r.localClient, obj, func() error {
	if err := actual.Reconcile(desired); err != nil {
	return err
	}
	utils.SetManagedBy(obj)
	utils.SetLabel(obj, r.labelComponentName, fluxComponent.GetName())
	return nil
	})

The solution could look like this:

result, errCU := controllerutil.CreateOrUpdate(ctx, r.localClient, obj, func() error { 
 	if err := actual.Reconcile(desired); err != nil { 
 		return err 
 	} 
  
 	// call function that applies labels and returns error 
    // error handling

 	return nil 
 })

[maximiliantech]

@ValentinGerlach let's have another session where exactly (just FluxComponents or ObjectComponents too?!) we want to apply this feature?