VictoriaMetrics/app/vminsert/relabel/relabel.go

127 lines
3.5 KiB
Go

package relabel
import (
"flag"
"fmt"
"sync/atomic"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/procutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompb"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
"github.com/VictoriaMetrics/metrics"
)
var relabelConfig = flag.String("relabelConfig", "", "Optional path to a file with relabeling rules, which are applied to all the ingested metrics. "+
"See https://victoriametrics.github.io/#relabeling for details")
// Init must be called after flag.Parse and before using the relabel package.
func Init() {
prcs, err := loadRelabelConfig()
if err != nil {
logger.Fatalf("cannot load relabelConfig: %s", err)
}
prcsGlobal.Store(&prcs)
if len(*relabelConfig) == 0 {
return
}
sighupCh := procutil.NewSighupChan()
go func() {
for range sighupCh {
logger.Infof("received SIGHUP; reloading -relabelConfig=%q...", *relabelConfig)
prcs, err := loadRelabelConfig()
if err != nil {
logger.Errorf("cannot load the updated relabelConfig: %s; preserving the previous config", err)
continue
}
prcsGlobal.Store(&prcs)
logger.Infof("successfully reloaded -relabelConfig=%q", *relabelConfig)
}
}()
}
var prcsGlobal atomic.Value
func loadRelabelConfig() ([]promrelabel.ParsedRelabelConfig, error) {
if len(*relabelConfig) == 0 {
return nil, nil
}
prcs, err := promrelabel.LoadRelabelConfigs(*relabelConfig)
if err != nil {
return nil, fmt.Errorf("error when reading -relabelConfig=%q: %w", *relabelConfig, err)
}
return prcs, nil
}
// HasRelabeling returns true if there is global relabeling.
func HasRelabeling() bool {
prcs := prcsGlobal.Load().(*[]promrelabel.ParsedRelabelConfig)
return len(*prcs) > 0
}
// Ctx holds relabeling context.
type Ctx struct {
// tmpLabels is used during ApplyRelabeling call.
tmpLabels []prompbmarshal.Label
}
// Reset resets ctx.
func (ctx *Ctx) Reset() {
labels := ctx.tmpLabels
for i := range labels {
label := &labels[i]
label.Name = ""
label.Value = ""
}
ctx.tmpLabels = ctx.tmpLabels[:0]
}
// ApplyRelabeling applies relabeling to the given labels and returns the result.
//
// The returned labels are valid until the next call to ApplyRelabeling.
func (ctx *Ctx) ApplyRelabeling(labels []prompb.Label) []prompb.Label {
prcs := prcsGlobal.Load().(*[]promrelabel.ParsedRelabelConfig)
if len(*prcs) == 0 {
// There are no relabeling rules.
return labels
}
// Convert src to prompbmarshal.Label format suitable for relabeling.
tmpLabels := ctx.tmpLabels[:0]
for _, label := range labels {
name := bytesutil.ToUnsafeString(label.Name)
if len(name) == 0 {
name = "__name__"
}
value := bytesutil.ToUnsafeString(label.Value)
tmpLabels = append(tmpLabels, prompbmarshal.Label{
Name: name,
Value: value,
})
}
// Apply relabeling
tmpLabels = promrelabel.ApplyRelabelConfigs(tmpLabels, 0, *prcs, true)
ctx.tmpLabels = tmpLabels
if len(tmpLabels) == 0 {
metricsDropped.Inc()
}
// Return back labels to the desired format.
dst := labels[:0]
for _, label := range tmpLabels {
name := bytesutil.ToUnsafeBytes(label.Name)
if label.Name == "__name__" {
name = nil
}
value := bytesutil.ToUnsafeBytes(label.Value)
dst = append(dst, prompb.Label{
Name: name,
Value: value,
})
}
return dst
}
var metricsDropped = metrics.NewCounter(`vm_relabel_metrics_dropped_total`)