func determineScaleClusterOpLockIfNecessary()

in controllers/solr_cluster_ops_util.go [36:87]
36 lines of code
12 McCabe index (conditional complexity)

func determineScaleClusterOpLockIfNecessary(ctx context.Context, r *SolrCloudReconciler, instance *solrv1beta1.SolrCloud, statefulSet *appsv1.StatefulSet, podList []corev1.Pod, logger logr.Logger) (clusterLockAcquired bool, retryLaterDuration time.Duration, err error) {
	desiredPods := int(*instance.Spec.Replicas)
	configuredPods := int(*statefulSet.Spec.Replicas)
	if desiredPods != configuredPods {
		// We do not do a "managed" scale-to-zero operation.
		// Only do a managed scale down if the desiredPods is positive.
		// The VacatePodsOnScaleDown option is enabled by default, so treat "nil" like "true"
		if desiredPods < configuredPods && desiredPods > 0 &&
			(instance.Spec.Scaling.VacatePodsOnScaleDown == nil || *instance.Spec.Scaling.VacatePodsOnScaleDown) {
			if len(podList) > configuredPods {
				// There are too many pods, the statefulSet controller has yet to delete unwanted pods.
				// Do not start the scale down until these extra pods are deleted.
				return false, time.Second * 5, nil
			}

			// Managed Scale down!
			originalStatefulSet := statefulSet.DeepCopy()
			statefulSet.Annotations[util.ClusterOpsLockAnnotation] = util.ScaleDownLock
			// The scaleDown metadata is the number of nodes to scale down to.
			// We only support scaling down one pod at-a-time when using a managed scale-down.
			// If the user wishes to scale down by multiple nodes, this ClusterOp will be done once-per-node.
			statefulSet.Annotations[util.ClusterOpsMetadataAnnotation] = strconv.Itoa(configuredPods - 1)
			if err = r.Patch(ctx, statefulSet, client.StrategicMergeFrom(originalStatefulSet)); err != nil {
				logger.Error(err, "Error while patching StatefulSet to start clusterOp", "clusterOp", util.ScaleDownLock, "clusterOpMetadata", configuredPods-1)
			} else {
				clusterLockAcquired = true
			}
		} else if desiredPods > configuredPods && (instance.Spec.Scaling.PopulatePodsOnScaleUp == nil || *instance.Spec.Scaling.PopulatePodsOnScaleUp) {
			if len(podList) < configuredPods {
				// There are not enough pods, the statefulSet controller has yet to create the previously desired pods.
				// Do not start the scale up until these missing pods are created.
				return false, time.Second * 5, nil
			}
			// Managed Scale up!
			originalStatefulSet := statefulSet.DeepCopy()
			statefulSet.Annotations[util.ClusterOpsLockAnnotation] = util.ScaleUpLock
			// The scaleUp metadata is the number of nodes that existed before the scaleUp.
			// This allows the scaleUp operation to know which pods will be empty after the statefulSet is scaledUp.
			statefulSet.Annotations[util.ClusterOpsMetadataAnnotation] = strconv.Itoa(configuredPods)
			// We want to set the number of replicas at the beginning of the scaleUp operation
			statefulSet.Spec.Replicas = pointer.Int32(int32(desiredPods))
			if err = r.Patch(ctx, statefulSet, client.StrategicMergeFrom(originalStatefulSet)); err != nil {
				logger.Error(err, "Error while patching StatefulSet to start clusterOp", "clusterOp", util.ScaleUpLock, "clusterOpMetadata", configuredPods, "newStatefulSetSize", desiredPods)
			} else {
				clusterLockAcquired = true
			}
		} else {
			err = scaleCloudUnmanaged(ctx, r, statefulSet, desiredPods, logger)
		}
	}
	return
}