statsd_exporter/pkg/line/line.go

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// Copyright 2013 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package line
import (
"fmt"
"strconv"
"strings"
"unicode/utf8"
"github.com/go-kit/log"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/statsd_exporter/pkg/event"
"github.com/prometheus/statsd_exporter/pkg/level"
"github.com/prometheus/statsd_exporter/pkg/mapper"
)
// Parser is a struct to hold configuration for parsing behavior
type Parser struct {
DogstatsdTagsEnabled bool
InfluxdbTagsEnabled bool
LibratoTagsEnabled bool
SignalFXTagsEnabled bool
}
// NewParser returns a new line parser
func NewParser() *Parser {
p := Parser{}
return &p
}
// EnableDogstatsdParsing option to enable dogstatsd tag parsing
func (p *Parser) EnableDogstatsdParsing() {
p.DogstatsdTagsEnabled = true
}
// EnableInfluxdbParsing option to enable influxdb tag parsing
func (p *Parser) EnableInfluxdbParsing() {
p.InfluxdbTagsEnabled = true
}
// EnableLibratoParsing option to enable librato tag parsing
func (p *Parser) EnableLibratoParsing() {
p.LibratoTagsEnabled = true
}
// EnableSignalFXParsing option to enable signalfx tag parsing
func (p *Parser) EnableSignalFXParsing() {
p.SignalFXTagsEnabled = true
}
func buildEvent(statType, metric string, value float64, relative bool, labels map[string]string) (event.Event, error) {
switch statType {
case "c":
return &event.CounterEvent{
CMetricName: metric,
CValue: float64(value),
CLabels: labels,
}, nil
case "g":
return &event.GaugeEvent{
GMetricName: metric,
GValue: float64(value),
GRelative: relative,
GLabels: labels,
}, nil
case "ms":
return &event.ObserverEvent{
OMetricName: metric,
OValue: float64(value) / 1000, // prometheus presumes seconds, statsd millisecond
OLabels: labels,
}, nil
case "h", "d":
return &event.ObserverEvent{
OMetricName: metric,
OValue: float64(value),
OLabels: labels,
}, nil
case "s":
return nil, fmt.Errorf("no support for StatsD sets")
default:
return nil, fmt.Errorf("bad stat type %s", statType)
}
}
func parseTag(component, tag string, separator rune, labels map[string]string, tagErrors prometheus.Counter, logger log.Logger) {
// Entirely empty tag is an error
if len(tag) == 0 {
tagErrors.Inc()
level.Debug(logger).Log("msg", "Empty name tag", "component", component)
return
}
for i, c := range tag {
if c == separator {
k := tag[:i]
v := tag[i+1:]
if len(k) == 0 || len(v) == 0 {
// Empty key or value is an error
tagErrors.Inc()
level.Debug(logger).Log("msg", "Malformed name tag", "k", k, "v", v, "component", component)
} else {
labels[mapper.EscapeMetricName(k)] = v
}
return
}
}
// Missing separator (no value) is an error
tagErrors.Inc()
level.Debug(logger).Log("msg", "Malformed name tag", "tag", tag, "component", component)
}
func parseNameTags(component string, labels map[string]string, tagErrors prometheus.Counter, logger log.Logger) {
lastTagEndIndex := 0
for i, c := range component {
if c == ',' {
tag := component[lastTagEndIndex:i]
lastTagEndIndex = i + 1
parseTag(component, tag, '=', labels, tagErrors, logger)
}
}
// If we're not off the end of the string, add the last tag
if lastTagEndIndex < len(component) {
tag := component[lastTagEndIndex:]
parseTag(component, tag, '=', labels, tagErrors, logger)
}
}
func trimLeftHash(s string) string {
if s != "" && s[0] == '#' {
return s[1:]
}
return s
}
func (p *Parser) ParseDogStatsDTags(component string, labels map[string]string, tagErrors prometheus.Counter, logger log.Logger) {
if p.DogstatsdTagsEnabled {
lastTagEndIndex := 0
for i, c := range component {
if c == ',' {
tag := component[lastTagEndIndex:i]
lastTagEndIndex = i + 1
parseTag(component, trimLeftHash(tag), ':', labels, tagErrors, logger)
}
}
// If we're not off the end of the string, add the last tag
if lastTagEndIndex < len(component) {
tag := component[lastTagEndIndex:]
parseTag(component, trimLeftHash(tag), ':', labels, tagErrors, logger)
}
}
}
func (p *Parser) parseNameAndTags(name string, labels map[string]string, tagErrors prometheus.Counter, logger log.Logger) string {
if p.SignalFXTagsEnabled {
// check for SignalFx tags first
// `[` delimits start of tags by SignalFx
// `]` delimits end of tags by SignalFx
// https://docs.signalfx.com/en/latest/integrations/agent/monitors/collectd-statsd.html
startIdx := strings.IndexRune(name, '[')
endIdx := strings.IndexRune(name, ']')
switch {
case startIdx != -1 && endIdx != -1:
// good signalfx tags
parseNameTags(name[startIdx+1:endIdx], labels, tagErrors, logger)
return name[:startIdx] + name[endIdx+1:]
case (startIdx != -1) != (endIdx != -1):
// only one bracket, return unparsed
level.Debug(logger).Log("msg", "invalid SignalFx tags, not parsing", "metric", name)
tagErrors.Inc()
return name
}
}
for i, c := range name {
// `#` delimits start of tags by Librato
// https://www.librato.com/docs/kb/collect/collection_agents/stastd/#stat-level-tags
// `,` delimits start of tags by InfluxDB
// https://www.influxdata.com/blog/getting-started-with-sending-statsd-metrics-to-telegraf-influxdb/#introducing-influx-statsd
if (c == '#' && p.LibratoTagsEnabled) || (c == ',' && p.InfluxdbTagsEnabled) {
parseNameTags(name[i+1:], labels, tagErrors, logger)
return name[:i]
}
}
return name
}
func (p *Parser) LineToEvents(line string, sampleErrors prometheus.CounterVec, samplesReceived prometheus.Counter, tagErrors prometheus.Counter, tagsReceived prometheus.Counter, logger log.Logger) event.Events {
events := event.Events{}
if line == "" {
return events
}
elements := strings.SplitN(line, ":", 2)
if len(elements) < 2 || len(elements[0]) == 0 || !utf8.ValidString(line) {
sampleErrors.WithLabelValues("malformed_line").Inc()
level.Debug(logger).Log("msg", "Bad line from StatsD", "line", line)
return events
}
labels := map[string]string{}
metric := p.parseNameAndTags(elements[0], labels, tagErrors, logger)
var samples []string
if strings.Contains(elements[1], "|#") {
// using DogStatsD tags
// don't allow mixed tagging styles
if len(labels) > 0 {
sampleErrors.WithLabelValues("mixed_tagging_styles").Inc()
level.Debug(logger).Log("msg", "Bad line (multiple tagging styles) from StatsD", "line", line)
return events
}
// disable multi-metrics
samples = elements[1:]
} else {
samples = strings.Split(elements[1], ":")
}
samples:
for _, sample := range samples {
samplesReceived.Inc()
components := strings.Split(sample, "|")
if len(components) < 2 || len(components) > 4 {
sampleErrors.WithLabelValues("malformed_component").Inc()
level.Debug(logger).Log("msg", "Bad component", "line", line)
continue
}
valueStr, statType := components[0], components[1]
var relative = false
if strings.Index(valueStr, "+") == 0 || strings.Index(valueStr, "-") == 0 {
relative = true
}
value, err := strconv.ParseFloat(valueStr, 64)
if err != nil {
level.Debug(logger).Log("msg", "Bad value", "value", valueStr, "line", line)
sampleErrors.WithLabelValues("malformed_value").Inc()
continue
}
multiplyEvents := 1
if len(components) >= 3 {
for _, component := range components[2:] {
if len(component) == 0 {
level.Debug(logger).Log("msg", "Empty component", "line", line)
sampleErrors.WithLabelValues("malformed_component").Inc()
continue samples
}
}
for _, component := range components[2:] {
switch component[0] {
case '@':
samplingFactor, err := strconv.ParseFloat(component[1:], 64)
if err != nil {
level.Debug(logger).Log("msg", "Invalid sampling factor", "component", component[1:], "line", line)
sampleErrors.WithLabelValues("invalid_sample_factor").Inc()
}
if samplingFactor == 0 {
samplingFactor = 1
}
if statType == "g" {
continue
} else if statType == "c" {
value /= samplingFactor
} else if statType == "ms" || statType == "h" || statType == "d" {
multiplyEvents = int(1 / samplingFactor)
}
case '#':
p.ParseDogStatsDTags(component[1:], labels, tagErrors, logger)
default:
level.Debug(logger).Log("msg", "Invalid sampling factor or tag section", "component", components[2], "line", line)
sampleErrors.WithLabelValues("invalid_sample_factor").Inc()
continue
}
}
}
if len(labels) > 0 {
tagsReceived.Inc()
}
for i := 0; i < multiplyEvents; i++ {
event, err := buildEvent(statType, metric, value, relative, labels)
if err != nil {
level.Debug(logger).Log("msg", "Error building event", "line", line, "error", err)
sampleErrors.WithLabelValues("illegal_event").Inc()
continue
}
events = append(events, event)
}
}
return events
}