stdouttrace

Documentation

Overview

Package stdouttrace contains an OpenTelemetry exporter for tracing telemetry to be written to an output destination as JSON.

Example

package main

import (
	"context"
	"fmt"
	"log"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
	"go.opentelemetry.io/otel/trace"
)

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

var (
	tracer = otel.GetTracerProvider().Tracer(
		instrumentationName,
		trace.WithInstrumentationVersion(instrumentationVersion),
		trace.WithSchemaURL(semconv.SchemaURL),
	)
)

func add(ctx context.Context, x, y int64) int64 {
	var span trace.Span
	_, span = tracer.Start(ctx, "Addition")
	defer span.End()

	return x + y
}

func multiply(ctx context.Context, x, y int64) int64 {
	var span trace.Span
	_, span = tracer.Start(ctx, "Multiplication")
	defer span.End()

	return x * y
}

func Resource() *resource.Resource {
	return resource.NewWithAttributes(
		semconv.SchemaURL,
		semconv.ServiceNameKey.String("stdout-example"),
		semconv.ServiceVersionKey.String("0.0.1"),
	)
}

func InstallExportPipeline(ctx context.Context) (func(context.Context) error, error) {
	exporter, err := stdouttrace.New(stdouttrace.WithPrettyPrint())
	if err != nil {
		return nil, fmt.Errorf("creating stdout exporter: %w", err)
	}

	tracerProvider := sdktrace.NewTracerProvider(
		sdktrace.WithBatcher(exporter),
		sdktrace.WithResource(Resource()),
	)
	otel.SetTracerProvider(tracerProvider)

	return tracerProvider.Shutdown, nil
}

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

	// Registers a tracer Provider globally.
	shutdown, err := InstallExportPipeline(ctx)
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		if err := shutdown(ctx); err != nil {
			log.Fatal(err)
		}
	}()

	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) ExportSpans(ctx context.Context, spans []trace.ReadOnlySpan) error
  • func (e *Exporter) MarshalLog() interface{}
  • func (e *Exporter) Shutdown(ctx context.Context) error
• type 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
}

Exporter is an implementation of trace.SpanSyncer that writes spans to stdout.

func New

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

New creates an Exporter with the passed options.

func (*Exporter) ExportSpans

func (e *Exporter) ExportSpans(ctx context.Context, spans []trace.ReadOnlySpan) error

ExportSpans writes spans in json format to stdout.

func (*Exporter) MarshalLog

func (e *Exporter) MarshalLog() interface{}

MarshalLog is the marshaling function used by the logging system to represent this exporter.

func (*Exporter) Shutdown

func (e *Exporter) Shutdown(ctx context.Context) error

Shutdown is called to stop the exporter, it preforms no action.

type Option

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

Option sets the value of an option for a Config.

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.