Accounting Service
This service calculates the total amount of sold products. This is only mocked and received orders are printed out.
Traces
Initializing Tracing
The OpenTelemetry SDK is initialized from main using the initTracerProvider
function.
func initTracerProvider() (*sdktrace.TracerProvider, error) {
ctx := context.Background()
exporter, err := otlptracegrpc.New(ctx)
if err != nil {
return nil, err
}
tp := sdktrace.NewTracerProvider(
sdktrace.WithBatcher(exporter),
sdktrace.WithResource(initResource()),
)
otel.SetTracerProvider(tp)
otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
return tp, nil
}
You should call TracerProvider.Shutdown() when your service is shutdown to
ensure all spans are exported. This service makes that call as part of a
deferred function in main
tp, err := initTracerProvider()
if err != nil {
log.Fatal(err)
}
defer func() {
if err := tp.Shutdown(context.Background()); err != nil {
log.Printf("Error shutting down tracer provider: %v", err)
}
}()
Adding Kafka ( Sarama ) auto-instrumentation
This service will receive the processed results of the Checkout Service via a Kafka topic. To instrument the Kafka client the ConsumerHandler implemented by the developer has to be wrapped.
handler := groupHandler{} // implements sarama.ConsumerGroupHandler
wrappedHandler := otelsarama.WrapConsumerGroupHandler(&handler)