statsd_exporter/pkg/mapper/mapper.go
Matthias Rampke d9f305b6f2
Inject the mappings count metric into the library package
so that it can be initialized with an exporter-specific name.

Signed-off-by: Matthias Rampke <mr@soundcloud.com>
2018-08-14 09:31:38 +00:00

210 lines
5.8 KiB
Go

// 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 mapper
import (
"fmt"
"io/ioutil"
"regexp"
"strings"
"sync"
"github.com/prometheus/client_golang/prometheus"
yaml "gopkg.in/yaml.v2"
)
var (
statsdMetricRE = `[a-zA-Z_](-?[a-zA-Z0-9_])+`
templateReplaceRE = `(\$\{?\d+\}?)`
metricLineRE = regexp.MustCompile(`^(\*\.|` + statsdMetricRE + `\.)+(\*|` + statsdMetricRE + `)$`)
metricNameRE = regexp.MustCompile(`^([a-zA-Z_]|` + templateReplaceRE + `)([a-zA-Z0-9_]|` + templateReplaceRE + `)*$`)
labelNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_]+$`)
)
type mapperConfigDefaults struct {
TimerType TimerType `yaml:"timer_type"`
Buckets []float64 `yaml:"buckets"`
Quantiles []metricObjective `yaml:"quantiles"`
MatchType MatchType `yaml:"match_type"`
}
type MetricMapper struct {
Defaults mapperConfigDefaults `yaml:"defaults"`
Mappings []MetricMapping `yaml:"mappings"`
mutex sync.Mutex
MappingsCount prometheus.Gauge
}
type matchMetricType string
type MetricMapping struct {
Match string `yaml:"match"`
Name string `yaml:"name"`
regex *regexp.Regexp
Labels prometheus.Labels `yaml:"labels"`
TimerType TimerType `yaml:"timer_type"`
Buckets []float64 `yaml:"buckets"`
Quantiles []metricObjective `yaml:"quantiles"`
MatchType MatchType `yaml:"match_type"`
HelpText string `yaml:"help"`
Action ActionType `yaml:"action"`
MatchMetricType MetricType `yaml:"match_metric_type"`
}
type metricObjective struct {
Quantile float64 `yaml:"quantile"`
Error float64 `yaml:"error"`
}
var defaultQuantiles = []metricObjective{
{Quantile: 0.5, Error: 0.05},
{Quantile: 0.9, Error: 0.01},
{Quantile: 0.99, Error: 0.001},
}
func (m *MetricMapper) InitFromYAMLString(fileContents string) error {
var n MetricMapper
if err := yaml.Unmarshal([]byte(fileContents), &n); err != nil {
return err
}
if n.Defaults.Buckets == nil || len(n.Defaults.Buckets) == 0 {
n.Defaults.Buckets = prometheus.DefBuckets
}
if n.Defaults.Quantiles == nil || len(n.Defaults.Quantiles) == 0 {
n.Defaults.Quantiles = defaultQuantiles
}
if n.Defaults.MatchType == MatchTypeDefault {
n.Defaults.MatchType = MatchTypeGlob
}
for i := range n.Mappings {
currentMapping := &n.Mappings[i]
// check that label is correct
for k := range currentMapping.Labels {
if !labelNameRE.MatchString(k) {
return fmt.Errorf("invalid label key: %s", k)
}
}
if currentMapping.Name == "" {
return fmt.Errorf("line %d: metric mapping didn't set a metric name", i)
}
if !metricNameRE.MatchString(currentMapping.Name) {
return fmt.Errorf("metric name '%s' doesn't match regex '%s'", currentMapping.Name, metricNameRE)
}
if currentMapping.MatchType == "" {
currentMapping.MatchType = n.Defaults.MatchType
}
if currentMapping.Action == "" {
currentMapping.Action = ActionTypeMap
}
if currentMapping.MatchType == MatchTypeGlob {
if !metricLineRE.MatchString(currentMapping.Match) {
return fmt.Errorf("invalid match: %s", currentMapping.Match)
}
// Translate the glob-style metric match line into a proper regex that we
// can use to match metrics later on.
metricRe := strings.Replace(currentMapping.Match, ".", "\\.", -1)
metricRe = strings.Replace(metricRe, "*", "([^.]*)", -1)
if regex, err := regexp.Compile("^" + metricRe + "$"); err != nil {
return fmt.Errorf("invalid match %s. cannot compile regex in mapping: %v", currentMapping.Match, err)
} else {
currentMapping.regex = regex
}
} else {
if regex, err := regexp.Compile(currentMapping.Match); err != nil {
return fmt.Errorf("invalid regex %s in mapping: %v", currentMapping.Match, err)
} else {
currentMapping.regex = regex
}
}
if currentMapping.TimerType == "" {
currentMapping.TimerType = n.Defaults.TimerType
}
if currentMapping.Buckets == nil || len(currentMapping.Buckets) == 0 {
currentMapping.Buckets = n.Defaults.Buckets
}
if currentMapping.Quantiles == nil || len(currentMapping.Quantiles) == 0 {
currentMapping.Quantiles = n.Defaults.Quantiles
}
}
m.mutex.Lock()
defer m.mutex.Unlock()
m.Defaults = n.Defaults
m.Mappings = n.Mappings
if m.MappingsCount != nil {
m.MappingsCount.Set(float64(len(n.Mappings)))
}
return nil
}
func (m *MetricMapper) InitFromFile(fileName string) error {
mappingStr, err := ioutil.ReadFile(fileName)
if err != nil {
return err
}
return m.InitFromYAMLString(string(mappingStr))
}
func (m *MetricMapper) GetMapping(statsdMetric string, statsdMetricType MetricType) (*MetricMapping, prometheus.Labels, bool) {
m.mutex.Lock()
defer m.mutex.Unlock()
for _, mapping := range m.Mappings {
matches := mapping.regex.FindStringSubmatchIndex(statsdMetric)
if len(matches) == 0 {
continue
}
mapping.Name = string(mapping.regex.ExpandString(
[]byte{},
mapping.Name,
statsdMetric,
matches,
))
if mt := mapping.MatchMetricType; mt != "" && mt != statsdMetricType {
continue
}
labels := prometheus.Labels{}
for label, valueExpr := range mapping.Labels {
value := mapping.regex.ExpandString([]byte{}, valueExpr, statsdMetric, matches)
labels[label] = string(value)
}
return &mapping, labels, true
}
return nil, nil, false
}