prometheus

README

OpenTelemetry-Go Prometheus Exporter

OpenTelemetry Prometheus exporter

Installation

go get -u go.opentelemetry.io/otel/exporters/metric/prometheus

Documentation

Index

• type Config
• type Exporter
  • func InstallNewPipeline(config Config, options ...pull.Option) (*Exporter, error)
  • func NewExportPipeline(config Config, options ...pull.Option) (*Exporter, error)
  • func (e *Exporter) Controller() *pull.Controller
  • func (e *Exporter) ExportKindFor(*metric.Descriptor, aggregation.Kind) export.ExportKind
  • func (e *Exporter) MeterProvider() metric.MeterProvider
  • func (e *Exporter) ServeHTTP(w http.ResponseWriter, r *http.Request)
  • func (e *Exporter) SetController(config Config, options ...pull.Option)

Examples

• NewExportPipeline

Types

type Config

type Config struct {
	// Registry is the prometheus registry that will be used as the default Registerer and
	// Gatherer if these are not specified.
	//
	// If not set a new empty Registry is created.
	Registry *prometheus.Registry

	// Registerer is the prometheus registerer to register
	// metrics with.
	//
	// If not specified the Registry will be used as default.
	Registerer prometheus.Registerer

	// Gatherer is the prometheus gatherer to gather
	// metrics with.
	//
	// If not specified the Registry will be used as default.
	Gatherer prometheus.Gatherer

	// DefaultSummaryQuantiles is the default summary quantiles
	// to use. Use nil to specify the system-default summary quantiles.
	DefaultSummaryQuantiles []float64

	// DefaultHistogramBoundaries defines the default histogram bucket
	// boundaries.
	DefaultHistogramBoundaries []float64
}

Config is a set of configs for the tally reporter.

type Exporter

type Exporter struct {
	// contains filtered or unexported fields
}

Exporter supports Prometheus pulls. It does not implement the sdk/export/metric.Exporter interface--instead it creates a pull controller and reads the latest checkpointed data on-scrape.

func InstallNewPipeline

func InstallNewPipeline(config Config, options ...pull.Option) (*Exporter, error)

InstallNewPipeline instantiates a NewExportPipeline and registers it globally. Typically called as:

hf, err := prometheus.InstallNewPipeline(prometheus.Config{...})

if err != nil {
	...
}
http.HandleFunc("/metrics", hf)
defer pipeline.Stop()
... Done

func NewExportPipeline

func NewExportPipeline(config Config, options ...pull.Option) (*Exporter, error)

NewExportPipeline sets up a complete export pipeline with the recommended setup, using the recommended selector and standard processor. See the pull.Options.

Example

package main

import (
	"bytes"
	"context"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/http/httptest"

	"go.opentelemetry.io/otel/api/metric"
	"go.opentelemetry.io/otel/exporters/metric/prometheus"
	"go.opentelemetry.io/otel/label"
	"go.opentelemetry.io/otel/sdk/metric/controller/pull"
	"go.opentelemetry.io/otel/sdk/resource"
)

func main() {
	// Create a meter
	exporter, err := prometheus.NewExportPipeline(
		prometheus.Config{},
		pull.WithResource(resource.New(label.String("R", "V"))),
	)
	if err != nil {
		panic(err)
	}
	meter := exporter.MeterProvider().Meter("example")
	ctx := context.Background()

	// Use two instruments
	counter := metric.Must(meter).NewInt64Counter(
		"a.counter",
		metric.WithDescription("Counts things"),
	)
	recorder := metric.Must(meter).NewInt64ValueRecorder(
		"a.valuerecorder",
		metric.WithDescription("Records values"),
	)

	counter.Add(ctx, 100, label.String("key", "value"))
	recorder.Record(ctx, 100, label.String("key", "value"))

	// GET the HTTP endpoint
	var input bytes.Buffer
	resp := httptest.NewRecorder()
	req, err := http.NewRequest("GET", "/", &input)
	if err != nil {
		panic(err)
	}
	exporter.ServeHTTP(resp, req)
	data, err := ioutil.ReadAll(resp.Result().Body)
	if err != nil {
		panic(err)
	}
	fmt.Print(string(data))

}

Output:

# HELP a_counter Counts things
# TYPE a_counter counter
a_counter{R="V",key="value"} 100
# HELP a_valuerecorder Records values
# TYPE a_valuerecorder histogram
a_valuerecorder_bucket{R="V",key="value",le="+Inf"} 1
a_valuerecorder_sum{R="V",key="value"} 100
a_valuerecorder_count{R="V",key="value"} 1

func (*Exporter) Controller

func (e *Exporter) Controller() *pull.Controller

Controller returns the controller object that coordinates collection for the SDK.

func (*Exporter) ExportKindFor

func (e *Exporter) ExportKindFor(*metric.Descriptor, aggregation.Kind) export.ExportKind

func (*Exporter) MeterProvider

func (e *Exporter) MeterProvider() metric.MeterProvider

MeterProvider returns the MeterProvider of this exporter.

func (*Exporter) ServeHTTP

func (e *Exporter) ServeHTTP(w http.ResponseWriter, r *http.Request)

func (*Exporter) SetController

func (e *Exporter) SetController(config Config, options ...pull.Option)

SetController sets up a standard *pull.Controller as the metric provider for this exporter.