stdoutmetric

Documentation

Overview

Package stdout contains an OpenTelemetry exporter for metric telemetry to be written to an output destination as JSON.

This package is currently in a pre-GA phase. Backwards incompatible changes may be introduced in subsequent minor version releases as we work to track the evolving OpenTelemetry specification and user feedback.

Example

package main

import (
	"context"
	"log"

	"go.opentelemetry.io/otel/exporters/stdout/stdoutmetric"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/metric/global"
	controller "go.opentelemetry.io/otel/sdk/metric/controller/basic"
	processor "go.opentelemetry.io/otel/sdk/metric/processor/basic"
	"go.opentelemetry.io/otel/sdk/metric/selector/simple"
)

const (
	instrumentationName    = "github.com/instrumentron"
	instrumentationVersion = "v0.1.0"
)

var (
	meter = global.GetMeterProvider().Meter(
		instrumentationName,
		metric.WithInstrumentationVersion(instrumentationVersion),
	)

	loopCounter = metric.Must(meter).NewInt64Counter("function.loops")
	paramValue  = metric.Must(meter).NewInt64Histogram("function.param")

	nameKey = attribute.Key("function.name")
)

func add(ctx context.Context, x, y int64) int64 {
	nameKV := nameKey.String("add")

	loopCounter.Add(ctx, 1, nameKV)
	paramValue.Record(ctx, x, nameKV)
	paramValue.Record(ctx, y, nameKV)

	return x + y
}

func multiply(ctx context.Context, x, y int64) int64 {
	nameKV := nameKey.String("multiply")

	loopCounter.Add(ctx, 1, nameKV)
	paramValue.Record(ctx, x, nameKV)
	paramValue.Record(ctx, y, nameKV)

	return x * y
}

func InstallExportPipeline(ctx context.Context) func() {
	exporter, err := stdoutmetric.New(stdoutmetric.WithPrettyPrint())
	if err != nil {
		log.Fatalf("creating stdoutmetric exporter: %v", err)
	}

	pusher := controller.New(
		processor.NewFactory(
			simple.NewWithInexpensiveDistribution(),
			exporter,
		),
		controller.WithExporter(exporter),
	)
	if err = pusher.Start(ctx); err != nil {
		log.Fatalf("starting push controller: %v", err)
	}
	global.SetMeterProvider(pusher)

	return func() {
		if err := pusher.Stop(ctx); err != nil {
			log.Fatalf("stopping push controller: %v", err)
		}
	}
}

func main() {
	ctx := context.Background()

	// Registers a meter Provider globally.
	cleanup := InstallExportPipeline(ctx)
	defer cleanup()

	log.Println("the answer is", add(ctx, multiply(ctx, multiply(ctx, 2, 2), 10), 2))
}

Index

• type Exporter
  • func New(options ...Option) (*Exporter, error)
  • func (e *Exporter) Export(_ context.Context, res *resource.Resource, ...) error
  • func (e *Exporter) ExportKindFor(desc *metric.Descriptor, kind aggregation.Kind) exportmetric.ExportKind
• type Option
  • func WithLabelEncoder(enc attribute.Encoder) Option
  • func WithPrettyPrint() Option
  • func WithWriter(w io.Writer) Option
  • func WithoutTimestamps() Option

Examples

• Package

Types

type Exporter

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

func New

func New(options ...Option) (*Exporter, error)

New creates an Exporter with the passed options.

func (*Exporter) Export

func (e *Exporter) Export(_ context.Context, res *resource.Resource, reader exportmetric.InstrumentationLibraryReader) error

func (*Exporter) ExportKindFor

func (e *Exporter) ExportKindFor(desc *metric.Descriptor, kind aggregation.Kind) exportmetric.ExportKind

type Option

type Option interface {
	// contains filtered or unexported methods
}

Option sets the value of an option for a Config.

func WithLabelEncoder

func WithLabelEncoder(enc attribute.Encoder) Option

WithLabelEncoder sets the label encoder used in export.

func WithPrettyPrint

func WithPrettyPrint() Option

WithPrettyPrint sets the export stream format to use JSON.

func WithWriter

func WithWriter(w io.Writer) Option

WithWriter sets the export stream destination.

func WithoutTimestamps

func WithoutTimestamps() Option

WithoutTimestamps sets the export stream to not include timestamps.