func addTaint()

in pkg/node/node.go [783:837]
50 lines of code
12 McCabe index (conditional complexity)

func addTaint(node *corev1.Node, nth Node, taintKey string, taintValue string, effectType string) error {
	effect := getTaintEffect(effectType)
	if nth.nthConfig.DryRun {
		log.Info().Msgf("Would have added taint (%s=%s:%s) to node %s, but dry-run flag was set", taintKey, taintValue, effect, nth.nthConfig.NodeName)
		return nil
	}

	retryDeadline := time.Now().Add(maxRetryDeadline)
	freshNode := node.DeepCopy()
	client := nth.drainHelper.Client
	var err error
	refresh := false
	for {
		if refresh {
			// Get the newest version of the node.
			freshNode, err = client.CoreV1().Nodes().Get(context.TODO(), node.Name, metav1.GetOptions{})
			if err != nil || freshNode == nil {
				nodeErr := fmt.Errorf("failed to get node %v: %w", node.Name, err)
				log.Err(nodeErr).
					Str("taint_key", taintKey).
					Str("node_name", node.Name).
					Msg("Error while adding taint on node")
				return nodeErr
			}
		}

		if !addTaintToSpec(freshNode, taintKey, taintValue, effect) {
			if !refresh {
				// Make sure we have the latest version before skipping update.
				refresh = true
				continue
			}
			return nil
		}
		_, err = client.CoreV1().Nodes().Update(context.TODO(), freshNode, metav1.UpdateOptions{})
		if err != nil && errors.IsConflict(err) && time.Now().Before(retryDeadline) {
			refresh = true
			time.Sleep(conflictRetryInterval)
			continue
		}

		if err != nil {
			log.Err(err).
				Str("taint_key", taintKey).
				Str("node_name", node.Name).
				Msg("Error while adding taint on node")
			return err
		}
		log.Warn().
			Str("taint_key", taintKey).
			Str("node_name", node.Name).
			Msg("Successfully added taint on node")
		return nil
	}
}