reconciler.go

// SPDX-FileCopyrightText: SAP SE or an SAP affiliate company and Gardener contributors
//
// SPDX-License-Identifier: Apache-2.0

package quota

import (
	"context"
	"fmt"

	corev1 "k8s.io/api/core/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/client-go/tools/events"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"

	controllermanagerconfigv1alpha1 "github.com/gardener/gardener/pkg/apis/config/controllermanager/v1alpha1"
	gardencorev1beta1 "github.com/gardener/gardener/pkg/apis/core/v1beta1"
	v1beta1constants "github.com/gardener/gardener/pkg/apis/core/v1beta1/constants"
	"github.com/gardener/gardener/pkg/controllerutils"
)

// Reconciler reconciles Quota.
type Reconciler struct {
	Client   client.Client
	Config   controllermanagerconfigv1alpha1.QuotaControllerConfiguration
	Recorder events.EventRecorder
}

// Reconcile performs the main reconciliation logic.
func (r *Reconciler) Reconcile(ctx context.Context, request reconcile.Request) (reconcile.Result, error) {
	log := logf.FromContext(ctx)

	quota := &gardencorev1beta1.Quota{}
	if err := r.Client.Get(ctx, request.NamespacedName, quota); err != nil {
		if apierrors.IsNotFound(err) {
			log.V(1).Info("Object is gone, stop reconciling")
			return reconcile.Result{}, nil
		}
		return reconcile.Result{}, fmt.Errorf("error retrieving object from store: %w", err)
	}

	// The deletionTimestamp labels a Quota as intended to get deleted. Before deletion,
	// it has to be ensured that no SecretBindings are depending on the Quota anymore.
	// When this happens the controller will remove the finalizers from the Quota so that it can be garbage collected.
	if quota.DeletionTimestamp != nil {
		if !sets.New(quota.Finalizers...).Has(gardencorev1beta1.GardenerName) {
			return reconcile.Result{}, nil
		}

		associatedSecretBindings, err := controllerutils.DetermineSecretBindingAssociations(ctx, r.Client, quota)
		if err != nil {
			return reconcile.Result{}, err
		}

		associatedCredentialsBindings, err := controllerutils.DetermineCredentialsBindingAssociations(ctx, r.Client, quota)
		if err != nil {
			return reconcile.Result{}, err
		}

		if len(associatedSecretBindings) == 0 && len(associatedCredentialsBindings) == 0 {
			log.Info("Neither SecretBindings nor CredentialsBindings are referencing the Quota, deletion accepted")

			if controllerutil.ContainsFinalizer(quota, gardencorev1beta1.GardenerName) {
				log.Info("Removing finalizer")
				if err := controllerutils.RemoveFinalizers(ctx, r.Client, quota, gardencorev1beta1.GardenerName); err != nil {
					return reconcile.Result{}, fmt.Errorf("failed to remove finalizer: %w", err)
				}
			}

			return reconcile.Result{}, nil
		}

		message := fmt.Sprintf("Cannot delete Quota, because the following resources are still referencing it: SecretBindings - %+v, CredentialsBindings - %+v", associatedSecretBindings, associatedCredentialsBindings)
		r.Recorder.Eventf(quota, nil, corev1.EventTypeNormal, v1beta1constants.EventResourceReferenced, gardencorev1beta1.EventActionReconcile, message)
		return reconcile.Result{}, fmt.Errorf("cannot delete Quota, because the following resources are still referencing it: SecretBindings - %+v, CredentialsBindings - %+v", associatedSecretBindings, associatedCredentialsBindings)
	}

	if !controllerutil.ContainsFinalizer(quota, gardencorev1beta1.GardenerName) {
		log.Info("Adding finalizer")
		if err := controllerutils.AddFinalizers(ctx, r.Client, quota, gardencorev1beta1.GardenerName); err != nil {
			return reconcile.Result{}, fmt.Errorf("failed to add finalizer: %w", err)
		}
	}

	return reconcile.Result{}, nil
}