enable gcp tracing env variable

.env.example

@@ -19,6 +19,11 @@ FIREBASE_AUTH_EMULATOR_HOST="localhost:9099"
 # - by the opentelemetry tracing agent to send traces to the collector
 GOOGLE_CLOUD_PROJECT="tokyo-country-381508"
 
+# Enable to activate GCP tracing
+# If activated, you MUST have GCP application default credentials set up - see https://cloud.google.com/trace/docs/setup/go-ot
+# Will send error logs (but the app will still run) if an unexisting project is specified in GOOGLE_CLOUD_PROJECT or 
+# if the runner does not have the correct permissions to use tracing on the project
+ENABLE_GCP_TRACING=false
 
 # configure the document storage backend with optional fake backends
 GCS_INGESTION_BUCKET="data-ingestion-bucket"

main.go

@@ -34,10 +34,19 @@ type dependencies struct {
 	Authentication      *api.Authentication
 	TokenHandler        *api.TokenHandler
 	SegmentClient       analytics.Client
-	OpenTelemetryTracer *trace.Tracer
+	OpenTelemetryTracer trace.Tracer
 }
 
 func initDependencies(conf AppConfiguration, signingKey *rsa.PrivateKey) (dependencies, error) {
+	tracer, err := tracing.Init(tracing.Configuration{
+		ApplicationName: "marble-backend",
+		Enabled:         conf.enableGcpTracing,
+		ProjectID:       conf.gcpProject,
+	})
+	if err != nil {
+		return dependencies{}, err
+	}
+
 	database, err := postgres.New(postgres.Configuration{
 		Host:                conf.pgConfig.Hostname,
 		Port:                conf.pgConfig.Port,
@@ -58,20 +67,10 @@ func initDependencies(conf AppConfiguration, signingKey *rsa.PrivateKey) (depend
 	segmentClient := analytics.New(conf.config.SegmentWriteKey)
 
 	deps := dependencies{
-		Authentication: api.NewAuthentication(tokenValidator),
-		TokenHandler:   api.NewTokenHandler(tokenGenerator),
-		SegmentClient:  segmentClient,
-	}
-
-	tracer, err := tracing.Init(tracing.Configuration{
-		Enabled:         conf.env != "development",
-		ApplicationName: "marble-backend",
-		ProjectID:       conf.gcpProject,
-	})
-	if err != nil {
-		fmt.Println("tracing.Init error: ", err)
-	} else {
-		deps.OpenTelemetryTracer = &tracer
+		Authentication:      api.NewAuthentication(tokenValidator),
+		OpenTelemetryTracer: tracer,
+		SegmentClient:       segmentClient,
+		TokenHandler:        api.NewTokenHandler(tokenGenerator),
 	}
 
 	return deps, nil
@@ -137,20 +136,22 @@ func runServer(ctx context.Context, appConfig AppConfiguration) {
 }
 
 type AppConfiguration struct {
-	env        string
-	port       string
-	gcpProject string
-	pgConfig   utils.PGConfig
-	config     models.GlobalConfiguration
-	sentryDsn  string
-	metabase   models.MetabaseConfiguration
+	env              string
+	port             string
+	gcpProject       string
+	enableGcpTracing bool
+	pgConfig         utils.PGConfig
+	config           models.GlobalConfiguration
+	sentryDsn        string
+	metabase         models.MetabaseConfiguration
 }
 
 func main() {
 	appConfig := AppConfiguration{
-		env:        utils.GetEnv("ENV", "development"),
-		port:       utils.GetRequiredEnv[string]("API_PORT"),
-		gcpProject: os.Getenv("GOOGLE_CLOUD_PROJECT"),
+		env:              utils.GetEnv("ENV", "development"),
+		port:             utils.GetRequiredEnv[string]("API_PORT"),
+		gcpProject:       os.Getenv("GOOGLE_CLOUD_PROJECT"),
+		enableGcpTracing: utils.GetEnv("ENABLE_GCP_TRACING", false),
 		pgConfig: utils.PGConfig{
 			Database:            "marble",
 			DbConnectWithSocket: utils.GetEnv("PG_CONNECT_WITH_SOCKET", false),

router.go

@@ -80,7 +80,7 @@ func initRouter(ctx context.Context, conf AppConfiguration, deps dependencies) *
 	r.Use(utils.StoreLoggerInContextMiddleware(logger))
 	r.Use(utils.StoreSegmentClientInContextMiddleware(deps.SegmentClient))
 	if deps.OpenTelemetryTracer != nil {
-		r.Use(utils.StoreOpenTelemetryTracerInContextMiddleware(*deps.OpenTelemetryTracer))
+		r.Use(utils.StoreOpenTelemetryTracerInContextMiddleware(deps.OpenTelemetryTracer))
 	}
 
 	return r