metrics

metrics

This is a helper package for creating consistent Prometheus metrics.

Quick Start

For creating new metrics using default buckets and quantiles and register them with default registry:

package main

import (
  "log"
  "net/http"

  "github.com/moorara/observe/metrics"
  "github.com/prometheus/client_golang/prometheus/promhttp"
)

func main() {
  mf := metrics.NewFactory(metrics.FactoryOptions{})

  // Create a histogram metric
  histogram := mf.Histogram("session_duration_seconds", "duration of user sessions", []string{"environment", "region"})
  histogram.WithLabelValues("prodcution", "us-east-1").Observe(0.0027)

  // Expose metrics via /metrics endpoint and an HTTP server
  http.Handle("/metrics", promhttp.Handler())
  log.Fatal(http.ListenAndServe(":8080", nil))
}

For creating new metrics using custom buckets and quantiles and register them with a new registry:

package main

import (
  "log"
  "net/http"

  "github.com/moorara/observe/metrics"
  "github.com/prometheus/client_golang/prometheus"
  "github.com/prometheus/client_golang/prometheus/promhttp"
)

func main() {
  registry := prometheus.NewRegistry()
  mf := metrics.NewFactory(metrics.FactoryOptions{
    Prefix:     "auth-service",
    Registerer: registry,
    Buckets:    []float64{0.01, 0.10, 0.50, 1.00, 5.00},
    Quantiles:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
  })

  // Create a histogram metric
  histogram := mf.Histogram("session_duration_seconds", "duration of user sessions", []string{"environment", "region"})
  histogram.WithLabelValues("prodcution", "us-east-1").Observe(0.0027)

  // Expose metrics via /metrics endpoint and an HTTP server
  http.Handle("/metrics", promhttp.HandlerFor(registry, promhttp.HandlerOpts{}))
  log.Fatal(http.ListenAndServe(":8080", nil))
}

Defaults

Default buckets:

[]float64{0.01, 0.10, 0.50, 1.00, 5.00}

Default quantiles:

map[float64]float64{
  0.1:  0.1,
  0.5:  0.05,
  0.95: 0.01,
  0.99: 0.001,
}