tempo.go

package observability

import (
	"context"
	"fmt"

	"github.com/correlatedlabs/pkg/go-common/env"
	"github.com/correlatedlabs/pkg/go-common/util"
	log "github.com/sirupsen/logrus"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
	"go.opentelemetry.io/otel/sdk/resource"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials"
)

type TempoExporter interface{}

func NewTempoExporter(config *env.CommonConfiguration) (TempoExporter, error) {
	if config.TempoEndpoint == "" {
		log.Debug("skipping tempo tracing exporting: no tempo endpoint")
	}

	if config.GrafanaUsername == "" {
		log.Debug("skipping tempo tracing exporting: no grafana username")
	}

	if config.GrafanaAPIKey == "" {
		log.Debug("skipping tempo tracing exporting: no grafana api key")
	}

	authenticationToken := util.B64Encode(fmt.Sprintf("%s:%s", config.GrafanaUsername, config.GrafanaAPIKey))

	tempoExporter, err := otlptrace.New(
		context.Background(),
		otlptracegrpc.NewClient(
			otlptracegrpc.WithTLSCredentials(credentials.NewClientTLSFromCert(nil, "")),
			otlptracegrpc.WithDialOption(grpc.WithBlock()),
			otlptracegrpc.WithEndpoint(config.TempoEndpoint),
			otlptracegrpc.WithHeaders(map[string]string{
				"Authentication": fmt.Sprintf("Basic %s", authenticationToken),
			}),
		),
	)
	if err != nil {
		return nil, err
	}
	res := resource.NewWithAttributes(
		semconv.SchemaURL,
		semconv.ServiceNameKey.String(config.ServerName),
	)

	tracerProvider := sdktrace.NewTracerProvider(
		sdktrace.WithSampler(sdktrace.AlwaysSample()),
		sdktrace.WithBatcher(tempoExporter),
		sdktrace.WithResource(res),
	)

	otel.SetTracerProvider(tracerProvider)

	log.Debug("initialized tempo tracing exporting")

	return nil, nil
}