tracing.go

package tracing

import (
	"context"
	"log"

	"github.com/gatewayd-io/gatewayd/config"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
	"go.opentelemetry.io/otel/sdk/resource"
	"go.opentelemetry.io/otel/sdk/trace"
	"google.golang.org/grpc/credentials"
)

func OTLPTracer(insecure bool, collectorURL, serviceName string) func(context.Context) error {
	secureOption := otlptracegrpc.WithTLSCredentials(credentials.NewClientTLSFromCert(nil, ""))
	if insecure {
		secureOption = otlptracegrpc.WithInsecure()
	}

	exporter, err := otlptrace.New(
		context.Background(),
		otlptracegrpc.NewClient(
			secureOption,
			otlptracegrpc.WithEndpoint(collectorURL),
		),
	)
	if err != nil {
		log.Fatal(err)
	}

	resources, err := resource.New(
		context.Background(),
		resource.WithAttributes(
			attribute.String("service.name", serviceName),
			attribute.String("service.version", config.Version),
			attribute.String("library.language", "go"),
		),
	)
	if err != nil {
		log.Fatal(err)
	}

	resources, _ = resource.Merge(
		resource.Default(),
		resources,
	)

	otel.SetTracerProvider(
		trace.NewTracerProvider(
			trace.WithSampler(trace.AlwaysSample()),
			trace.WithBatcher(exporter),
			trace.WithResource(resources),
		),
	)
	return exporter.Shutdown
}