func regionTopologyHandler()

in plugins/in_tree_volume.go [341:397]
43 lines of code
15 McCabe index (conditional complexity)

func regionTopologyHandler(pv *v1.PersistentVolume, regionParser regionParserFn) error {

	// Make sure the necessary fields exist
	if pv == nil || pv.Spec.NodeAffinity == nil || pv.Spec.NodeAffinity.Required == nil ||
		pv.Spec.NodeAffinity.Required.NodeSelectorTerms == nil || len(pv.Spec.NodeAffinity.Required.NodeSelectorTerms) == 0 {
		return nil
	}

	zoneLabel, regionLabel := getTopologyLabel(pv)

	// process each term
	for index, nodeSelectorTerm := range pv.Spec.NodeAffinity.Required.NodeSelectorTerms {
		// In the first loop, see if regionLabel already exist
		regionExist := false
		var zoneVals []string
		for _, nsRequirement := range nodeSelectorTerm.MatchExpressions {
			if nsRequirement.Key == regionLabel {
				regionExist = true
				break
			} else if nsRequirement.Key == zoneLabel {
				zoneVals = append(zoneVals, nsRequirement.Values...)
			}
		}
		if regionExist {
			// Regionlabel already exist in this term, skip it
			continue
		}
		// If no regionLabel found, generate region label from the zoneLabel we collect from this term
		regionVal, err := regionParser(zoneVals)
		if err != nil {
			return err
		}
		// Add the regionVal to this term
		pv.Spec.NodeAffinity.Required.NodeSelectorTerms[index].MatchExpressions =
			append(pv.Spec.NodeAffinity.Required.NodeSelectorTerms[index].MatchExpressions, v1.NodeSelectorRequirement{
				Key:      regionLabel,
				Operator: v1.NodeSelectorOpIn,
				Values:   []string{regionVal},
			})

	}

	// Add region label
	regionVals := getTopologyValues(pv, regionLabel)
	if len(regionVals) == 1 {
		// We should only have exactly 1 region value
		if pv.Labels == nil {
			pv.Labels = make(map[string]string)
		}
		_, regionOK := pv.Labels[regionLabel]
		if !regionOK {
			pv.Labels[regionLabel] = regionVals[0]
		}
	}

	return nil
}