controller: add PersistentVolumeClaimController

This controller watches for annotation on PVC,
if matches with `reclaimspace.csiaddons.openshift.io/schedule`
which can specify a schedule, a reclaimspace cron job cr
is created for that PVC witha  generated name having pvc-name
as prefix.

Signed-off-by: Rakshith R <[email protected]>

PROJECT

@@ -35,4 +35,9 @@ resources:
   group: csiaddons
   kind: ReclaimSpaceCronJob
   version: v1alpha1
+- controller: true
+  group: core
+  kind: PersistentVolumeClaim
+  path: k8s.io/api/core/v1
+  version: v1
 version: "3"

cmd/manager/main.go

@@ -122,6 +122,13 @@ func main() {
 		setupLog.Error(err, "unable to create controller", "controller", "ReclaimSpaceCronJob")
 		os.Exit(1)
 	}
+	if err = (&controllers.PersistentVolumeClaimReconciler{
+		Client: mgr.GetClient(),
+		Scheme: mgr.GetScheme(),
+	}).SetupWithManager(mgr); err != nil {
+		setupLog.Error(err, "unable to create controller", "controller", "PersistentVolumeClaim")
+		os.Exit(1)
+	}
 	//+kubebuilder:scaffold:builder
 
 	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {

config/rbac/role.yaml

@@ -21,6 +21,15 @@ rules:
   - get
   - list
   - watch
+- apiGroups:
+  - ""
+  resources:
+  - persistentvolumeclaims
+  verbs:
+  - get
+  - list
+  - patch
+  - watch
 - apiGroups:
   - csiaddons.openshift.io
   resources:

controllers/persistentvolumeclaim_controller.go

@@ -0,0 +1,331 @@
+/*
+Copyright 2022 The Kubernetes-CSI-Addons Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package controllers
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"time"
+
+	csiaddonsv1alpha1 "github.com/csi-addons/kubernetes-csi-addons/api/v1alpha1"
+
+	"github.com/go-logr/logr"
+	"github.com/robfig/cron/v3"
+	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/event"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/predicate"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+)
+
+// PersistentVolumeClaimReconciler reconciles a PersistentVolumeClaim object
+type PersistentVolumeClaimReconciler struct {
+	client.Client
+	Scheme *runtime.Scheme
+}
+
+var (
+	rsCronJobScheduleTimeAnnotation = "reclaimspace." + csiaddonsv1alpha1.GroupVersion.Group + "/schedule"
+	rsCronJobNameAnnotation         = "reclaimspace." + csiaddonsv1alpha1.GroupVersion.Group + "/cronjob"
+)
+
+const (
+	defaultSchedule = "@weekly"
+)
+
+//+kubebuilder:rbac:groups=core,resources=persistentvolumeclaims,verbs=get;list;watch;patch
+//+kubebuilder:rbac:groups=csiaddons.openshift.io,resources=reclaimspacecronjobs,verbs=get;list;watch;create;delete;update
+
+// Reconcile is part of the main kubernetes reconciliation loop which aims to
+// move the current state of the cluster closer to the desired state.
+// This is triggered when `reclaimspace.csiaddons.openshift/schedule` annotation
+// is found on newly created PVC or if there is a change in value of the annotation.
+// It is also triggered by any changes to the child cronjob.
+func (r *PersistentVolumeClaimReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+	logger := log.FromContext(ctx)
+
+	// Fetch PersistentVolumeClaim instance
+	pvc := &corev1.PersistentVolumeClaim{}
+	err := r.Client.Get(ctx, req.NamespacedName, pvc)
+	if err != nil {
+		if apierrors.IsNotFound(err) {
+			// Request object not found, could have been deleted after reconcile request.
+			logger.Info("PersistentVolumeClaim resource not found")
+
+			return ctrl.Result{}, nil
+		}
+
+		return ctrl.Result{}, err
+	}
+
+	rsCronJob, err := r.findChildCronJob(ctx, &logger, &req)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+	if rsCronJob != nil {
+		logger = logger.WithValues("ReclaimSpaceCronJobName", rsCronJob.Name)
+	}
+
+	annotations := pvc.GetAnnotations()
+	schedule, scheduleFound := getScheduleFromAnnotation(&logger, annotations)
+	if !scheduleFound {
+		// if schedule is not found,
+		// delete cron job.
+		if rsCronJob != nil {
+			err = r.deleteChildCronJob(ctx, &logger, rsCronJob)
+			if err != nil {
+				return ctrl.Result{}, err
+			}
+		}
+		// delete name from annotation.
+		_, nameFound := annotations[rsCronJobNameAnnotation]
+		if nameFound {
+			// remove name annotation by patching it to null.
+			patch := []byte(fmt.Sprintf(`{"metadata":{"annotations":{%q: null}}}`, rsCronJobNameAnnotation))
+			err = r.Client.Patch(ctx, pvc, client.RawPatch(types.StrategicMergePatchType, patch))
+			if err != nil {
+				logger.Error(err, "Failed to remove annotation")
+
+				return ctrl.Result{}, err
+			}
+		}
+		logger.Info("Annotation not set, exiting reconcile")
+		// no schedule annotation set, just dequeue.
+		return ctrl.Result{}, nil
+	}
+	logger = logger.WithValues("Schedule", schedule)
+
+	if rsCronJob != nil {
+		newRSCronJob := constructRSCronJob(rsCronJob.Name, req.Namespace, schedule, pvc.Name)
+		if reflect.DeepEqual(newRSCronJob.Spec, rsCronJob.Spec) {
+			logger.Info("No change in reclaimSpaceCronJob.Spec, exiting reconcile")
+
+			return ctrl.Result{}, nil
+		}
+		// update rsCronJob spec
+		rsCronJob.Spec = newRSCronJob.Spec
+		err = r.Client.Update(ctx, rsCronJob)
+		if err != nil {
+			logger.Error(err, "Failed to update reclaimSpaceCronJob")
+
+			return ctrl.Result{}, err
+		}
+		logger.Info("Successfully updated reclaimSpaceCronJob")
+
+		return ctrl.Result{}, nil
+	}
+
+	rsCronJobName := generateCronJobName(req.Name)
+	logger = logger.WithValues("ReclaimSpaceCronJobName", rsCronJobName)
+	// add cronjob name in annotations.
+	patch := []byte(fmt.Sprintf(`{"metadata":{"annotations":{%q:%q}}}`, rsCronJobNameAnnotation, rsCronJobName))
+	err = r.Client.Patch(ctx, pvc, client.RawPatch(types.StrategicMergePatchType, patch))
+	if err != nil {
+		logger.Error(err, "Failed to update annotation")
+
+		return ctrl.Result{}, err
+	}
+
+	rsCronJob = constructRSCronJob(rsCronJobName, req.Namespace, schedule, pvc.Name)
+	err = ctrl.SetControllerReference(pvc, rsCronJob, r.Scheme)
+	if err != nil {
+		logger.Error(err, "Failed to set controllerReference")
+
+		return ctrl.Result{}, err
+	}
+
+	err = r.Client.Create(ctx, rsCronJob)
+	if err != nil {
+		logger.Error(err, "Failed to create reclaimSpaceCronJob")
+
+		return ctrl.Result{}, err
+	}
+	logger.Info("Successfully created reclaimSpaceCronJob")
+
+	return ctrl.Result{}, nil
+}
+
+// SetupWithManager sets up the controller with the Manager.
+func (r *PersistentVolumeClaimReconciler) SetupWithManager(mgr ctrl.Manager) error {
+	err := mgr.GetFieldIndexer().IndexField(
+		context.Background(),
+		&csiaddonsv1alpha1.ReclaimSpaceCronJob{},
+		jobOwnerKey,
+		extractOwnerNameFromPVCObj)
+	if err != nil {
+		return err
+	}
+
+	pred := predicate.Funcs{
+		CreateFunc: func(e event.CreateEvent) bool {
+			if e.Object == nil {
+				return false
+			}
+			// reconcile only if schedule annotation is found.
+			_, ok := e.Object.GetAnnotations()[rsCronJobScheduleTimeAnnotation]
+
+			return ok
+		},
+		UpdateFunc: func(e event.UpdateEvent) bool {
+			if e.ObjectNew == nil || e.ObjectOld == nil {
+				return false
+			}
+			// reconcile only if schedule annotation between old and new objects have changed.
+			oldSchdeule, oldOk := e.ObjectOld.GetAnnotations()[rsCronJobScheduleTimeAnnotation]
+			newSchdeule, newOk := e.ObjectNew.GetAnnotations()[rsCronJobScheduleTimeAnnotation]
+
+			return oldOk != newOk || oldSchdeule != newSchdeule
+		},
+	}
+
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&corev1.PersistentVolumeClaim{}).
+		Owns(&csiaddonsv1alpha1.ReclaimSpaceCronJob{}).
+		WithEventFilter(pred).
+		Complete(r)
+}
+
+// findChildCronJob lists child cronjobs, returns the first cronjob and
+// deletes the rest if there are more than one cronjob.
+func (r *PersistentVolumeClaimReconciler) findChildCronJob(
+	ctx context.Context,
+	logger *logr.Logger,
+	req *reconcile.Request) (*csiaddonsv1alpha1.ReclaimSpaceCronJob, error) {
+	var childJobs csiaddonsv1alpha1.ReclaimSpaceCronJobList
+	var activeJob *csiaddonsv1alpha1.ReclaimSpaceCronJob
+	err := r.List(ctx,
+		&childJobs,
+		client.InNamespace(req.Namespace),
+		client.MatchingFields{jobOwnerKey: req.Name})
+	if err != nil {
+		logger.Error(err, "Failed to list child reclaimSpaceCronJobs")
+
+		return activeJob, fmt.Errorf("Failed to list child reclaimSpaceCronJob: %v", err)
+	}
+
+	for i, job := range childJobs.Items {
+		if i == 0 {
+			activeJob = &job
+			continue
+		}
+		// there should be only one child cronjob, delete rest if they
+		// exist
+		err = r.deleteChildCronJob(ctx, logger, &job)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return activeJob, nil
+}
+
+// deleteChildCronJob deletes child cron job, ignoring not found error.
+func (r *PersistentVolumeClaimReconciler) deleteChildCronJob(
+	ctx context.Context,
+	logger *logr.Logger,
+	job *csiaddonsv1alpha1.ReclaimSpaceCronJob) error {
+	err := r.Delete(ctx, job)
+	if client.IgnoreNotFound(err) != nil {
+		logger.Error(err, "Failed to delete child reclaimSpaceCronJob",
+			"ReclaimSpaceCronJobName", job.Name)
+
+		return fmt.Errorf("Failed to delete child reclaimSpaceCronJob %q: %w",
+			job.Name, err)
+	}
+
+	return nil
+}
+
+// getScheduleFromAnnotation parses schedule and returns it.
+// A error is logged and default schedule is returned if it
+// is not in cron format.
+func getScheduleFromAnnotation(
+	logger *logr.Logger,
+	annotations map[string]string) (string, bool) {
+	schedule, ok := annotations[rsCronJobScheduleTimeAnnotation]
+	if !ok {
+		return "", false
+	}
+	_, err := cron.ParseStandard(schedule)
+	if err != nil {
+		logger.Info(fmt.Sprintf("Parsing given schedule %q failed, using default schedule %q",
+			schedule,
+			defaultSchedule),
+			"error",
+			err)
+
+		return defaultSchedule, true
+	}
+
+	return schedule, true
+}
+
+// constructRSCronJob constructs and returns ReclaimSpaceCronJob.
+func constructRSCronJob(name, namespace, schedule, pvcName string) *csiaddonsv1alpha1.ReclaimSpaceCronJob {
+	failedJobsHistoryLimit := defaultFailedJobsHistoryLimit
+	successfulJobsHistoryLimit := defaultSuccessfulJobsHistoryLimit
+	return &csiaddonsv1alpha1.ReclaimSpaceCronJob{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      name,
+			Namespace: namespace,
+		},
+		Spec: csiaddonsv1alpha1.ReclaimSpaceCronJobSpec{
+			Schedule: schedule,
+			JobSpec: csiaddonsv1alpha1.ReclaimSpaceJobTemplateSpec{
+				Spec: csiaddonsv1alpha1.ReclaimSpaceJobSpec{
+					Target:               csiaddonsv1alpha1.TargetSpec{PersistentVolumeClaim: pvcName},
+					BackoffLimit:         defaultBackoffLimit,
+					RetryDeadlineSeconds: defaultRetryDeadlineSeconds,
+				},
+			},
+			FailedJobsHistoryLimit:     &failedJobsHistoryLimit,
+			SuccessfulJobsHistoryLimit: &successfulJobsHistoryLimit,
+		},
+	}
+}
+
+// extractOwnerNameFromPVCObj extracts owner.Name from the object if it is
+// of type ReclaimSpaceCronJob and has a PVC as its owner.
+func extractOwnerNameFromPVCObj(rawObj client.Object) []string {
+	// extract the owner from job object.
+	job, ok := rawObj.(*csiaddonsv1alpha1.ReclaimSpaceCronJob)
+	if !ok {
+		return nil
+	}
+	owner := metav1.GetControllerOf(job)
+	if owner == nil {
+		return nil
+	}
+	if owner.APIVersion != "v1" || owner.Kind != "PersistentVolumeClaim" {
+		return nil
+	}
+
+	return []string{owner.Name}
+}
+
+// generateCronJobName returns unique name by suffixing parent name
+// with time hash.
+func generateCronJobName(parentName string) string {
+	return fmt.Sprintf("%s-%d", parentName, time.Now().Unix())
+}