Files
karma/internal/transform/strip.go
2026-03-11 13:10:15 +00:00

76 lines
3.1 KiB
Go

package transform
import (
"regexp"
"slices"
"strings"
"github.com/prometheus/prometheus/model/labels"
"github.com/prymitive/karma/internal/models"
sliceutils "github.com/prymitive/karma/internal/slices"
)
// StripLabels allows filtering out some labels from alerts
// it takes the list of label keys to ignore and alert label map
// it will return label map without labels found on the ignore list
func StripLabels(keptLabels, ignoredLabels []string, keptLabelsRegex, ignoredLabelsRegex []*regexp.Regexp,
sourceLabels labels.Labels,
) labels.Labels {
// empty keep lists means keep everything by default
keepAll := len(keptLabels) == 0 && len(keptLabelsRegex) == 0
// if we keep everything and there's nothing to strip then simply return source labels as-is
if keepAll && len(ignoredLabels) == 0 && len(ignoredLabelsRegex) == 0 {
return sourceLabels
}
b := labels.NewBuilder(labels.EmptyLabels())
var inKeep, inStrip bool
sourceLabels.Range(func(l labels.Label) {
// is explicitly marked to be kept
inKeep = slices.Contains(keptLabels, l.Name) || sliceutils.MatchesAnyRegex(l.Name, keptLabelsRegex)
// is explicitly marked to be stripped
inStrip = slices.Contains(ignoredLabels, l.Name) || sliceutils.MatchesAnyRegex(l.Name, ignoredLabelsRegex)
if (keepAll || inKeep) && !inStrip {
// strip leading and trailing space in label value
// this is to normalize values in case space is added by Alertmanager rules
b.Set(l.Name, strings.TrimSpace(l.Value))
}
})
return b.Labels()
}
// StripReceivers allows filtering all alerts for specified receiver(s)
// it will return true if alert uses receiver that should be stripped
func StripReceivers(keptReceivers, ignoredReceivers []string, keptReceiversRegex, ignoredReceiversRegex []*regexp.Regexp, alertReceiver string) bool {
// empty keep lists means keep everything by default
keepAll := len(keptReceivers) == 0 && len(keptReceiversRegex) == 0
// is explicitly marked to be kept
inKeep := slices.Contains(keptReceivers, alertReceiver) || sliceutils.MatchesAnyRegex(alertReceiver, keptReceiversRegex)
// is explicitly marked to be stripped
inStrip := slices.Contains(ignoredReceivers, alertReceiver) || sliceutils.MatchesAnyRegex(alertReceiver, ignoredReceiversRegex)
if (keepAll || inKeep) && !inStrip {
return false
}
return true
}
// StripAnnotations allows to ignore some annotations when pulling data
// Alertmanager, it will return true if passed annotation name should be
// stripped
func StripAnnotations(keptAnnotations, ignoredAnnotations []string, sourceAnnotations models.Annotations) models.Annotations {
// empty keep list means keep everything by default
keepAll := len(keptAnnotations) == 0
annotations := make(models.Annotations, 0, len(sourceAnnotations))
for _, annotation := range sourceAnnotations {
// is explicitly marked to be kept
inKeep := slices.Contains(keptAnnotations, annotation.Name)
// is explicitly marked to be stripped
inStrip := slices.Contains(ignoredAnnotations, annotation.Name)
if (keepAll || inKeep) && !inStrip {
annotations = append(annotations, annotation)
}
}
return annotations
}