prometheus_counter:inc and labels with undefined value

[meox]

I'd like to define a counter with a set of labels that can be "undefined" times to times depending on certain condition.
Or I'd like to have a way to avoid reporting the undefined labels to prometheus.

Is it possibile?

[NelsonVides]

Hey there! Sorry for the delayed answer, haven't seen this issue earlier. From what I understand, I guess the best would be on the place where the label value is created, you can case ... of and not increment any counter if the label is undefined.

    prometheus_counter:declare([{name, my_service_requests_total},
                                {help, "Requests count"},
                                {labels, my_label}]).

And later

    case MyLabel of
        undefined ->
            ok ->
        ActualValue ->
            prometheus_counter:inc(my_service_requests_total, [ActualValue])
    end,

But not sure if that's what you meant with your question.