/
metrics.go
324 lines (301 loc) · 8.82 KB
/
metrics.go
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package stages
import (
"fmt"
"math"
"reflect"
"strconv"
"strings"
"time"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"github.com/mitchellh/mapstructure"
"github.com/pkg/errors"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/model"
"github.com/metrico/loki-apache/pkg/logentry/metric"
)
const (
MetricTypeCounter = "counter"
MetricTypeGauge = "gauge"
MetricTypeHistogram = "histogram"
ErrEmptyMetricsStageConfig = "empty metric stage configuration"
ErrMetricsStageInvalidType = "invalid metric type '%s', metric type must be one of 'counter', 'gauge', or 'histogram'"
ErrInvalidIdleDur = "max_idle_duration could not be parsed as a time.Duration: '%s'"
ErrSubSecIdleDur = "max_idle_duration less than 1s not allowed"
)
// MetricConfig is a single metrics configuration.
type MetricConfig struct {
MetricType string `mapstructure:"type"`
Description string `mapstructure:"description"`
Source *string `mapstructure:"source"`
Prefix string `mapstructure:"prefix"`
IdleDuration *string `mapstructure:"max_idle_duration"`
maxIdleSec int64
Config interface{} `mapstructure:"config"`
}
// MetricsConfig is a set of configured metrics.
type MetricsConfig map[string]MetricConfig
func validateMetricsConfig(cfg MetricsConfig) error {
if cfg == nil {
return errors.New(ErrEmptyMetricsStageConfig)
}
for name, config := range cfg {
//If the source is not defined, default to the metric name
if config.Source == nil {
cp := cfg[name]
nm := name
cp.Source = &nm
cfg[name] = cp
}
config.MetricType = strings.ToLower(config.MetricType)
if config.MetricType != MetricTypeCounter &&
config.MetricType != MetricTypeGauge &&
config.MetricType != MetricTypeHistogram {
return errors.Errorf(ErrMetricsStageInvalidType, config.MetricType)
}
// Set the idle duration for metrics
if config.IdleDuration != nil {
d, err := time.ParseDuration(*config.IdleDuration)
if err != nil {
return errors.Errorf(ErrInvalidIdleDur, err)
}
if d < 1*time.Second {
return errors.New(ErrSubSecIdleDur)
}
cp := cfg[name]
cp.maxIdleSec = int64(d.Seconds())
cfg[name] = cp
} else {
cp := cfg[name]
cp.maxIdleSec = int64(5 * time.Minute.Seconds())
cfg[name] = cp
}
}
return nil
}
// newMetricStage creates a new set of metrics to process for each log entry
func newMetricStage(logger log.Logger, config interface{}, registry prometheus.Registerer) (Stage, error) {
cfgs := &MetricsConfig{}
err := mapstructure.Decode(config, cfgs)
if err != nil {
return nil, err
}
err = validateMetricsConfig(*cfgs)
if err != nil {
return nil, err
}
metrics := map[string]prometheus.Collector{}
for name, cfg := range *cfgs {
var collector prometheus.Collector
customPrefix := ""
if cfg.Prefix != "" {
customPrefix = cfg.Prefix
} else {
customPrefix = "promtail_custom_"
}
switch strings.ToLower(cfg.MetricType) {
case MetricTypeCounter:
collector, err = metric.NewCounters(customPrefix+name, cfg.Description, cfg.Config, cfg.maxIdleSec)
if err != nil {
return nil, err
}
case MetricTypeGauge:
collector, err = metric.NewGauges(customPrefix+name, cfg.Description, cfg.Config, cfg.maxIdleSec)
if err != nil {
return nil, err
}
case MetricTypeHistogram:
collector, err = metric.NewHistograms(customPrefix+name, cfg.Description, cfg.Config, cfg.maxIdleSec)
if err != nil {
return nil, err
}
}
if collector != nil {
registry.MustRegister(collector)
metrics[name] = collector
}
}
return toStage(&metricStage{
logger: logger,
cfg: *cfgs,
metrics: metrics,
}), nil
}
// metricStage creates and updates prometheus metrics based on extracted pipeline data
type metricStage struct {
logger log.Logger
cfg MetricsConfig
metrics map[string]prometheus.Collector
}
// Process implements Stage
func (m *metricStage) Process(labels model.LabelSet, extracted map[string]interface{}, t *time.Time, entry *string) {
for name, collector := range m.metrics {
// There is a special case for counters where we count even if there is no match in the extracted map.
if c, ok := collector.(*metric.Counters); ok {
if c != nil && c.Cfg.MatchAll != nil && *c.Cfg.MatchAll {
if c.Cfg.CountBytes != nil && *c.Cfg.CountBytes {
if entry != nil {
m.recordCounter(name, c, labels, len(*entry))
}
} else {
m.recordCounter(name, c, labels, nil)
}
continue
}
}
if v, ok := extracted[*m.cfg[name].Source]; ok {
switch vec := collector.(type) {
case *metric.Counters:
m.recordCounter(name, vec, labels, v)
case *metric.Gauges:
m.recordGauge(name, vec, labels, v)
case *metric.Histograms:
m.recordHistogram(name, vec, labels, v)
}
} else {
level.Debug(m.logger).Log("msg", "source does not exist", "err", fmt.Sprintf("source: %s, does not exist", *m.cfg[name].Source))
}
}
}
// Name implements Stage
func (m *metricStage) Name() string {
return StageTypeMetric
}
// recordCounter will update a counter metric
func (m *metricStage) recordCounter(name string, counter *metric.Counters, labels model.LabelSet, v interface{}) {
// If value matching is defined, make sure value matches.
if counter.Cfg.Value != nil {
stringVal, err := getString(v)
if err != nil {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to string, "+
"can't perform value comparison", "metric", name, "err",
fmt.Sprintf("can't convert %v to string", reflect.TypeOf(v)))
}
return
}
if *counter.Cfg.Value != stringVal {
return
}
}
switch counter.Cfg.Action {
case metric.CounterInc:
counter.With(labels).Inc()
case metric.CounterAdd:
f, err := getFloat(v)
if err != nil || f < 0 {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to positive float", "metric", name, "err", err)
}
return
}
counter.With(labels).Add(f)
}
}
// recordGauge will update a gauge metric
func (m *metricStage) recordGauge(name string, gauge *metric.Gauges, labels model.LabelSet, v interface{}) {
// If value matching is defined, make sure value matches.
if gauge.Cfg.Value != nil {
stringVal, err := getString(v)
if err != nil {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to string, "+
"can't perform value comparison", "metric", name, "err",
fmt.Sprintf("can't convert %v to string", reflect.TypeOf(v)))
}
return
}
if *gauge.Cfg.Value != stringVal {
return
}
}
switch gauge.Cfg.Action {
case metric.GaugeSet:
f, err := getFloat(v)
if err != nil || f < 0 {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to positive float", "metric", name, "err", err)
}
return
}
gauge.With(labels).Set(f)
case metric.GaugeInc:
gauge.With(labels).Inc()
case metric.GaugeDec:
gauge.With(labels).Dec()
case metric.GaugeAdd:
f, err := getFloat(v)
if err != nil || f < 0 {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to positive float", "metric", name, "err", err)
}
return
}
gauge.With(labels).Add(f)
case metric.GaugeSub:
f, err := getFloat(v)
if err != nil || f < 0 {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to positive float", "metric", name, "err", err)
}
return
}
gauge.With(labels).Sub(f)
}
}
// recordHistogram will update a Histogram metric
func (m *metricStage) recordHistogram(name string, histogram *metric.Histograms, labels model.LabelSet, v interface{}) {
// If value matching is defined, make sure value matches.
if histogram.Cfg.Value != nil {
stringVal, err := getString(v)
if err != nil {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to string, "+
"can't perform value comparison", "metric", name, "err",
fmt.Sprintf("can't convert %v to string", reflect.TypeOf(v)))
}
return
}
if *histogram.Cfg.Value != stringVal {
return
}
}
f, err := getFloat(v)
if err != nil {
if Debug {
level.Debug(m.logger).Log("msg", "failed to convert extracted value to float", "metric", name, "err", err)
}
return
}
histogram.With(labels).Observe(f)
}
// getFloat will take the provided value and return a float64 if possible
func getFloat(unk interface{}) (float64, error) {
switch i := unk.(type) {
case float64:
return i, nil
case float32:
return float64(i), nil
case int64:
return float64(i), nil
case int32:
return float64(i), nil
case int:
return float64(i), nil
case uint64:
return float64(i), nil
case uint32:
return float64(i), nil
case uint:
return float64(i), nil
case string:
return strconv.ParseFloat(i, 64)
case bool:
if i {
return float64(1), nil
}
return float64(0), nil
default:
return math.NaN(), fmt.Errorf("can't convert %v to float64", unk)
}
}