semconv: Add ErrorType function

[pellared]

Problem Statement

There is no easy way to set error.type (stable) attribute.

Proposed Solution

We can add a helper method to semconv package:

func ErrorType(err error) attribute.KeyValue {
	t := reflect.TypeOf(err)
	var value string
	if t.PkgPath() == "" && t.Name() == "" {
		// Likely a builtin type.
		value = t.String()
	} else {
		value = fmt.Sprintf("%s.%s", t.PkgPath(), t.Name())
	}

	if value == "" {
		return ErrorTypeOther
	}
	return ErrorTypeKey.String(value)
}

Additional Context

Related to:

• Do not use span.RecordError for terminating errors opentelemetry-go-contrib#7470

[Bakhtiyar-Garashov]

Hi. I would like to work on this. Please, assign me if it is feasible

[pellared]

@Bakhtiyar-Garashov, sure.

Just please notice that the semconv packages are generated so you would need to add the code here https://github.com/open-telemetry/opentelemetry-go/tree/main/internal/tools/semconvkit/templates and then regenerate semconv/v1.34.0.