otel

func HTTPMiddleware ¶ added in v0.2.0

func HTTPMiddleware(tp oteltrace.TracerProvider, opts ...HTTPOption) func(http.Handler) http.Handler

HTTPMiddleware returns an HTTP middleware that creates a span for each request. It extracts W3C trace context from incoming headers, records HTTP attributes (method, path, status code), and marks 5xx responses as errors.

If tp is nil, the global OpenTelemetry TracerProvider is used.

func NewProviderFromEnv ¶ added in v0.5.1

func NewProviderFromEnv(serviceName string, opts ...ProviderOption) (*sdktrace.TracerProvider, func(context.Context) error, error)

NewProviderFromEnv builds an OTLP-exporting *sdktrace.TracerProvider driven by standard OTEL_EXPORTER_OTLP_* environment variables, plus serviceName as the service.name resource attribute.

This factors out the generic OTLP-provider-construction boilerplate (exporter protocol/endpoint resolution, resource attributes, sampling) that's otherwise hand-rolled per service. It deliberately does not cover app-specific concerns like PII redaction; wrap the returned provider's exporter/processor chain (via WithSpanProcessor) for that.

The returned shutdown func flushes and closes the exporter; callers should defer it. Pass the returned provider to NewTracer to adapt it to modulex.Tracer:

tp, shutdown, err := otel.NewProviderFromEnv("my-service")
if err != nil {
    return err
}
defer shutdown(context.Background())
tracer := otel.NewTracer(tp)

func NewTracer ¶

func NewTracer(provider oteltrace.TracerProvider) modulex.Tracer

NewTracer creates a Modulex Tracer backed by OpenTelemetry.

If provider is nil, the global OpenTelemetry TracerProvider is used. The returned tracer is safe for concurrent use.

func SubscriberMiddleware ¶ added in v0.2.0

func SubscriberMiddleware(tp oteltrace.TracerProvider, opts ...SubscriberOption) func(topic string, handler modulex.EventHandler) modulex.EventHandler

SubscriberMiddleware wraps an EventHandler with automatic span creation. Each handler invocation gets a child span named after the topic, with the topic recorded as an attribute. Handler errors are recorded on the span.

If tp is nil, the global OpenTelemetry TracerProvider is used.