func()

in pkg/controllers/clusterresourceplacement/controller.go [265:351]

• 70 lines of code
• 17 McCabe index (conditional complexity)

func (r *Reconciler) getOrCreateClusterSchedulingPolicySnapshot(ctx context.Context, crp *fleetv1beta1.ClusterResourcePlacement, revisionHistoryLimit int) (*fleetv1beta1.ClusterSchedulingPolicySnapshot, error) {
	crpKObj := klog.KObj(crp)
	schedulingPolicy := crp.Spec.Policy.DeepCopy()
	if schedulingPolicy != nil {
		schedulingPolicy.NumberOfClusters = nil // will exclude the numberOfClusters
	}
	policyHash, err := resource.HashOf(schedulingPolicy)
	if err != nil {
		klog.ErrorS(err, "Failed to generate policy hash of crp", "clusterResourcePlacement", crpKObj)
		return nil, controller.NewUnexpectedBehaviorError(err)
	}

	// latestPolicySnapshotIndex should be -1 when there is no snapshot.
	latestPolicySnapshot, latestPolicySnapshotIndex, err := r.lookupLatestClusterSchedulingPolicySnapshot(ctx, crp)
	if err != nil {
		return nil, err
	}

	if latestPolicySnapshot != nil && string(latestPolicySnapshot.Spec.PolicyHash) == policyHash {
		if err := r.ensureLatestPolicySnapshot(ctx, crp, latestPolicySnapshot); err != nil {
			return nil, err
		}
		klog.V(2).InfoS("Policy has not been changed and updated the existing clusterSchedulingPolicySnapshot", "clusterResourcePlacement", crpKObj, "clusterSchedulingPolicySnapshot", klog.KObj(latestPolicySnapshot))
		return latestPolicySnapshot, nil
	}

	// Need to create new snapshot when 1) there is no snapshots or 2) the latest snapshot hash != current one.
	// mark the last policy snapshot as inactive if it is different from what we have now
	if latestPolicySnapshot != nil &&
		string(latestPolicySnapshot.Spec.PolicyHash) != policyHash &&
		latestPolicySnapshot.Labels[fleetv1beta1.IsLatestSnapshotLabel] == strconv.FormatBool(true) {
		// set the latest label to false first to make sure there is only one or none active policy snapshot
		latestPolicySnapshot.Labels[fleetv1beta1.IsLatestSnapshotLabel] = strconv.FormatBool(false)
		if err := r.Client.Update(ctx, latestPolicySnapshot); err != nil {
			klog.ErrorS(err, "Failed to set the isLatestSnapshot label to false", "clusterResourcePlacement", crpKObj, "clusterSchedulingPolicySnapshot", klog.KObj(latestPolicySnapshot))
			return nil, controller.NewUpdateIgnoreConflictError(err)
		}
		klog.V(2).InfoS("Marked the existing clusterSchedulingPolicySnapshot as inactive", "clusterResourcePlacement", crpKObj, "clusterSchedulingPolicySnapshot", klog.KObj(latestPolicySnapshot))
	}

	// delete redundant snapshot revisions before creating a new snapshot to guarantee that the number of snapshots
	// won't exceed the limit.
	if err := r.deleteRedundantSchedulingPolicySnapshots(ctx, crp, revisionHistoryLimit); err != nil {
		return nil, err
	}

	// create a new policy snapshot
	latestPolicySnapshotIndex++
	latestPolicySnapshot = &fleetv1beta1.ClusterSchedulingPolicySnapshot{
		ObjectMeta: metav1.ObjectMeta{
			Name: fmt.Sprintf(fleetv1beta1.PolicySnapshotNameFmt, crp.Name, latestPolicySnapshotIndex),
			Labels: map[string]string{
				fleetv1beta1.CRPTrackingLabel:      crp.Name,
				fleetv1beta1.IsLatestSnapshotLabel: strconv.FormatBool(true),
				fleetv1beta1.PolicyIndexLabel:      strconv.Itoa(latestPolicySnapshotIndex),
			},
			Annotations: map[string]string{
				fleetv1beta1.CRPGenerationAnnotation: strconv.FormatInt(crp.Generation, 10),
			},
		},
		Spec: fleetv1beta1.SchedulingPolicySnapshotSpec{
			Policy:     schedulingPolicy,
			PolicyHash: []byte(policyHash),
		},
	}
	policySnapshotKObj := klog.KObj(latestPolicySnapshot)
	if err := controllerutil.SetControllerReference(crp, latestPolicySnapshot, r.Scheme); err != nil {
		klog.ErrorS(err, "Failed to set owner reference", "clusterSchedulingPolicySnapshot", policySnapshotKObj)
		// should never happen
		return nil, controller.NewUnexpectedBehaviorError(err)
	}
	// make sure each policySnapshot should always have the annotation if CRP is selectN type
	if crp.Spec.Policy != nil &&
		crp.Spec.Policy.PlacementType == fleetv1beta1.PickNPlacementType &&
		crp.Spec.Policy.NumberOfClusters != nil {
		// Note that all policy snapshots should have the CRP generation annotation set already,
		// so the Annotations field will not be nil.
		latestPolicySnapshot.Annotations[fleetv1beta1.NumberOfClustersAnnotation] = strconv.Itoa(int(*crp.Spec.Policy.NumberOfClusters))
	}

	if err := r.Client.Create(ctx, latestPolicySnapshot); err != nil {
		klog.ErrorS(err, "Failed to create new clusterSchedulingPolicySnapshot", "clusterSchedulingPolicySnapshot", policySnapshotKObj)
		return nil, controller.NewAPIServerError(false, err)
	}
	klog.V(2).InfoS("Created new clusterSchedulingPolicySnapshot", "clusterResourcePlacement", crpKObj, "clusterSchedulingPolicySnapshot", policySnapshotKObj)
	return latestPolicySnapshot, nil
}