Opentelemetry tracer initilization

trace.go

package main

import (
	"context"
	"crypto/tls"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/sdk/resource"

	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
)

// tracingConfig is used to configure the driver used to send traces to the Otel Collector
type tracingConfig struct {
	CollectorAddress string
	Environment      string
	ServiceName      string
	ServiceVersion   string
}

var (
	// traceExporter exports trace data in the OTLP wire format.
	traceExporter *otlptrace.Exporter
	// tracerProvider holds a new and configured sdktrace.TracerProvider.
	tracerProvider *sdktrace.TracerProvider
)

// initTracer initializes and configures a trace provider in order to generate traces and send them to a collector.
func initTracer(ctx context.Context, conf tracingConfig) error {
	var err error
	traceExporter, err = otlptracehttp.New(ctx,
		otlptracehttp.WithTLSClientConfig(
			&tls.Config{InsecureSkipVerify: true},
		),
		otlptracehttp.WithEndpoint(conf.CollectorAddress),
		otlptracehttp.WithCompression(otlptracehttp.GzipCompression),
	)
	if err != nil {
		return err
	}

	res, err := resource.New(ctx,
		resource.WithAttributes(
			semconv.ServiceNameKey.String(conf.ServiceName),
			semconv.DeploymentEnvironmentKey.String(conf.Environment),
			semconv.ServiceVersionKey.String(conf.ServiceVersion),
		),
	)
	if err != nil {
		return err
	}

	bsp := sdktrace.NewBatchSpanProcessor(traceExporter)
	tracerProvider = sdktrace.NewTracerProvider(
		sdktrace.WithSampler(sdktrace.AlwaysSample()),
		sdktrace.WithResource(res),
		sdktrace.WithSpanProcessor(bsp),
	)
	otel.SetTracerProvider(tracerProvider)
	otel.SetTextMapPropagator(
		propagation.NewCompositeTextMapPropagator(
			propagation.TraceContext{},
			propagation.Baggage{},
		))

	return nil
}