HTTP status code label

[emschwartz]

A lot of people write HTTP services. Should autometrics automatically add the HTTP status code as a label for the function.calls metric if the function returns an HTTP response?

We would probably consider this an optional feature. If it's not too difficult in a given language to detect whether the function is returning an HTTP response, it could look at the status code and add that as a label.

An argument against doing this might be that users might have or want to use some metrics middleware for their HTTP framework to produce a full suite of HTTP-related metrics.

If we do add this, we could use OpenTelemetry's convention and call the label http.response.status_code, even though that's technically defined as an attribute on their http.server.duration metric.