Add option to specify namespace of metrics

[Otterpohl]

If not already possible, i would like for the metrics to be namespaced if a namespace option was specified

autometrics.Init(
    autometrics.WithNamespace("imaginary_application"),
)

function_calls_duration_seconds_count would become imaginary_application_function_calls_duration_seconds_count

if this is not already possible then i would be happy to raise a PR to add this

[gagbo]

Hello,

It’s not exactly possible like that, we didn’t think of this because

• it increases the risk of having a metrics explosion leading to extra used storage, and
• because it makes it harder to "pre-write" useful queries against arbitrary names like this, leading to harder alert/monitoring tooling

You can kind of get it when using a specific serviceName (also available with the Prometheus backend ) , because the serviceName gets exported to Prometheus as a service_name label and you can filter on this, e.g. topk(3, function_calls_count{service_name="imaginary_application"})