Function RandomAttrFromTrace

pkg/util/trace_info.go:365–416

RandomAttrFromTrace returns a random attribute from the trace for use in search validation. Integer attributes are never chosen: they are not unique enough for search.

(t *tempopb.Trace)

// RandomAttrFromTrace returns a random attribute from the trace for use in search validation.
// Integer attributes are never chosen: they are not unique enough for search.
func RandomAttrFromTrace(t *tempopb.Trace) *v1common.KeyValue {
	r := newRand(time.Now())

	if len(t.ResourceSpans) == 0 {
		return nil
	}
	batch := randFrom(r, t.ResourceSpans)

	// maybe choose resource attribute
	res := batch.Resource
	if len(res.Attributes) > 0 && r.Int()%2 == 1 {
		attr := randFrom(r, res.Attributes)
		// skip service.name because service names have low cardinality and produce queries with
		// too many results in tempo-vulture
		if attr.Key != "service.name" {
			if attr.Value == nil {
				return attr
			}
			if _, ok := attr.Value.Value.(*v1common.AnyValue_IntValue); !ok {
				return attr
			}
		}
	}

	if len(batch.ScopeSpans) == 0 {
		return nil
	}
	ss := randFrom(r, batch.ScopeSpans)

	if len(ss.Spans) == 0 {
		return nil
	}
	span := randFrom(r, ss.Spans)

	if len(span.Attributes) == 0 {
		return nil
	}

	// Pick only from non-integer attributes (integers are not unique enough for search).
	nonIntAttrs := make([]*v1common.KeyValue, 0, len(span.Attributes))
	for _, a := range span.Attributes {
		if a.Value == nil {
			nonIntAttrs = append(nonIntAttrs, a)
		} else if _, ok := a.Value.Value.(*v1common.AnyValue_IntValue); !ok {
			nonIntAttrs = append(nonIntAttrs, a)
		}
	}
	if len(nonIntAttrs) == 0 {
		return nil
	}
	return randFrom(r, nonIntAttrs)
}

func randFrom[T any](r *rand.Rand, s []T) T {
	return s[r.Intn(len(s))]