observability

name	observability
description	Tracing with OpenTelemetry and structured logging with slog. Use when adding observability to services, handlers, or debugging production issues.
userInvokable	true

Observability

References: Examples

Tracing (OpenTelemetry)

Example

Mandatory for: repositories, API clients, Lambdas, usecases

func (s *Service) GetOrder(ctx context.Context, id string) (*Order, error) {
    ctx, span := tracing.StartSpan(ctx, "Service.GetOrder")
    defer span.End()

    span.SetAttributes(attribute.String("order.id", id))
    // business logic...
}

Structured Logging (slog)

Example

Use log/slog with structured JSON:

slog.InfoContext(ctx, "order retrieved",
    "order_id", orderID,
    "reference_id", referenceID,
)

Log Levels

Level	Use When
INFO	Normal operations, successful requests
WARN	Recoverable errors, degraded state, fallbacks used
ERROR	Failures requiring attention, unrecoverable errors

Lambda Lifecycle

Example

func main() {
    ctx := context.Background()

    otelShutdown, err := otel.Setup(ctx)
    if err != nil {
        fmt.Printf("Error setting up OpenTelemetry: %v\n", err)
        os.Exit(1)
    }

    defer func() {
        if err := otelShutdown(context.Background()); err != nil {
            fmt.Printf("Error shutting down: %v\n", err)
        }
    }()

    lambda.Start(otellambda.InstrumentHandler(handler))
}

HTTP Client Tracing

Example

client := tracing.NewRestyClient(baseURL,
    tracing.WithTimeout(30*time.Second),
    tracing.WithRetryCount(3),
)