rancher/opni-monitoring

package storage

import "github.com/rancher/opni-monitoring/pkg/core"

type SelectorPredicate func(*core.Cluster) bool

type ClusterSelector struct {
    ClusterIDs    []string
    LabelSelector *core.LabelSelector
    MatchOptions  core.MatchOptions
}

func (p ClusterSelector) Predicate() SelectorPredicate {
    emptyLabelSelector := p.LabelSelector.IsEmpty()
    if emptyLabelSelector && len(p.ClusterIDs) == 0 {
        switch {
        case p.MatchOptions&core.MatchOptions_EmptySelectorMatchesNone != 0:
            return func(cluster *core.Cluster) bool { return false }
        default:
            return func(c *core.Cluster) bool { return true }
        }
    }
    idSet := map[string]struct{}{}
    for _, id := range p.ClusterIDs {
        idSet[id] = struct{}{}
    }
    return func(c *core.Cluster) bool {
        id := c.Id
        if _, ok := idSet[id]; ok {
            return true
        }
        if emptyLabelSelector {
            return false
        }
        return labelSelectorMatches(p.LabelSelector, c.GetMetadata().GetLabels())
    }
}

func labelSelectorMatches(selector *core.LabelSelector, labels map[string]string) bool {
    for key, value := range selector.MatchLabels {
        if labels[key] != value {
            return false
        }
    }
    for _, req := range selector.MatchExpressions {
        switch core.LabelSelectorOperator(req.Operator) {
        case core.LabelSelectorOpIn:
            ok := false
            for _, value := range req.Values {
                if labels[req.Key] == value {
                    ok = true
                    break
                }
            }
            if !ok {
                return false
            }
        case core.LabelSelectorOpNotIn:
            if v, ok := labels[req.Key]; !ok {
                return false
            } else {
                for _, value := range req.Values {
                    if v == value {
                        return false
                    }
                }
                return true
            }
        case core.LabelSelectorOpExists:
            if _, ok := labels[req.Key]; !ok {
                return false
            }
        case core.LabelSelectorOpDoesNotExist:
            if _, ok := labels[req.Key]; ok {
                return false
            }
        }
    }
    return true
}