VictoriaMetrics/app/vmagent/remotewrite/relabel.go
2021-03-25 17:59:30 +02:00

140 lines
4.4 KiB
Go

package remotewrite
import (
"flag"
"fmt"
"strings"
"sync"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
)
var (
unparsedLabelsGlobal = flagutil.NewArray("remoteWrite.label", "Optional label in the form 'name=value' to add to all the metrics before sending them to -remoteWrite.url. "+
"Pass multiple -remoteWrite.label flags in order to add multiple labels to metrics before sending them to remote storage")
relabelConfigPathGlobal = flag.String("remoteWrite.relabelConfig", "", "Optional path to file with relabel_config entries. These entries are applied to all the metrics "+
"before sending them to -remoteWrite.url. See https://victoriametrics.github.io/vmagent.html#relabeling for details")
relabelConfigPaths = flagutil.NewArray("remoteWrite.urlRelabelConfig", "Optional path to relabel config for the corresponding -remoteWrite.url")
)
var labelsGlobal []prompbmarshal.Label
// CheckRelabelConfigs checks -remoteWrite.relabelConfig and -remoteWrite.urlRelabelConfig.
func CheckRelabelConfigs() error {
_, err := loadRelabelConfigs()
return err
}
func loadRelabelConfigs() (*relabelConfigs, error) {
var rcs relabelConfigs
if *relabelConfigPathGlobal != "" {
global, err := promrelabel.LoadRelabelConfigs(*relabelConfigPathGlobal)
if err != nil {
return nil, fmt.Errorf("cannot load -remoteWrite.relabelConfig=%q: %w", *relabelConfigPathGlobal, err)
}
rcs.global = global
}
if len(*relabelConfigPaths) > len(*remoteWriteURLs) {
return nil, fmt.Errorf("too many -remoteWrite.urlRelabelConfig args: %d; it mustn't exceed the number of -remoteWrite.url args: %d",
len(*relabelConfigPaths), len(*remoteWriteURLs))
}
rcs.perURL = make([]*promrelabel.ParsedConfigs, len(*remoteWriteURLs))
for i, path := range *relabelConfigPaths {
if len(path) == 0 {
// Skip empty relabel config.
continue
}
prc, err := promrelabel.LoadRelabelConfigs(path)
if err != nil {
return nil, fmt.Errorf("cannot load relabel configs from -remoteWrite.urlRelabelConfig=%q: %w", path, err)
}
rcs.perURL[i] = prc
}
return &rcs, nil
}
type relabelConfigs struct {
global *promrelabel.ParsedConfigs
perURL []*promrelabel.ParsedConfigs
}
// initLabelsGlobal must be called after parsing command-line flags.
func initLabelsGlobal() {
labelsGlobal = nil
for _, s := range *unparsedLabelsGlobal {
if len(s) == 0 {
continue
}
n := strings.IndexByte(s, '=')
if n < 0 {
logger.Fatalf("missing '=' in `-remoteWrite.label`. It must contain label in the form `name=value`; got %q", s)
}
labelsGlobal = append(labelsGlobal, prompbmarshal.Label{
Name: s[:n],
Value: s[n+1:],
})
}
}
func (rctx *relabelCtx) applyRelabeling(tss []prompbmarshal.TimeSeries, extraLabels []prompbmarshal.Label, pcs *promrelabel.ParsedConfigs) []prompbmarshal.TimeSeries {
if len(extraLabels) == 0 && pcs.Len() == 0 {
// Nothing to change.
return tss
}
tssDst := tss[:0]
labels := rctx.labels[:0]
for i := range tss {
ts := &tss[i]
labelsLen := len(labels)
labels = append(labels, ts.Labels...)
// extraLabels must be added before applying relabeling according to https://prometheus.io/docs/prometheus/latest/configuration/configuration/#remote_write
for j := range extraLabels {
extraLabel := &extraLabels[j]
tmp := promrelabel.GetLabelByName(labels[labelsLen:], extraLabel.Name)
if tmp != nil {
tmp.Value = extraLabel.Value
} else {
labels = append(labels, *extraLabel)
}
}
labels = pcs.Apply(labels, labelsLen, true)
if len(labels) == labelsLen {
// Drop the current time series, since relabeling removed all the labels.
continue
}
tssDst = append(tssDst, prompbmarshal.TimeSeries{
Labels: labels[labelsLen:],
Samples: ts.Samples,
})
}
rctx.labels = labels
return tssDst
}
type relabelCtx struct {
// pool for labels, which are used during the relabeling.
labels []prompbmarshal.Label
}
func (rctx *relabelCtx) reset() {
promrelabel.CleanLabels(rctx.labels)
rctx.labels = rctx.labels[:0]
}
var relabelCtxPool = &sync.Pool{
New: func() interface{} {
return &relabelCtx{}
},
}
func getRelabelCtx() *relabelCtx {
return relabelCtxPool.Get().(*relabelCtx)
}
func putRelabelCtx(rctx *relabelCtx) {
rctx.labels = rctx.labels[:0]
relabelCtxPool.Put(rctx)
}