On Thu, 23 Apr 2020 at 10:46, Brian Brazil <[email protected]> wrote:
> On Wed, 22 Apr 2020 at 22:04, 'Chris Taylor' via Prometheus Developers < > [email protected]> wrote: > >> Dear Prometheans, >> >> posting this here because the Github issue template suggested discussing >> changes on the >> mailing list first. >> >> I just discovered the `promauto.With(Reigsterer)` API[1] today, which >> looked like a nice way >> to ensure that metrics are registered with a Registerer when they are >> created. >> >> In my use-case, the code receives the Registerer as a dependency. >> Since it may be called multiple times, I'd like to be able to register >> metrics multiple times, >> As an example, imagine writing a middleware to instrument an HTTP >> handler, similar to >> package promhttp: >> > > It sounds like your instrumentation might be at the wrong level, have you > tried instrumenting this at the http router instead? > sorry, I wasn't clear enough. The HTTP handler was just supposed to be a familiar stand-in for "some library code that is instrumented with metrics that users instantiate multiple times". The concrete use-case I was looking at when I wrote the email related to service discovery that can be used in various contexts, but my question really applies to any time you'd want to wrap some interface in a version with instrumentation. > > Brian > > >> >> func InstrumentedHandler(r Registerer, next http.Handler) http.Handler { >> // register a bunch of metrics on `r` and return a Handler that >> // bumps them appropriately >> } >> >> Currently, my code uses prometheus.Register(), and checks whether the >> returned error is >> a prometheus.AlreadyRegisteredError to get access to the >> previously-registered metric and >> uses that instead. >> >> It'd be easy enough to write a "lenient" version of promauto.Filter that >> uses this logic. >> Would it make sense to add this to client_golang? If so, what do you >> think the API should >> look like? >> >> Thanks for your time! >> Chris >> >> [1]: >> https://pkg.go.dev/github.com/prometheus/[email protected]/prometheus/promauto?tab=doc#With >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Prometheus Developers" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/prometheus-developers/97aa0973-1a26-4a16-af27-b1d926971c21%40googlegroups.com >> <https://groups.google.com/d/msgid/prometheus-developers/97aa0973-1a26-4a16-af27-b1d926971c21%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > Brian Brazil > www.robustperception.io > -- You received this message because you are subscribed to the Google Groups "Prometheus Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/prometheus-developers/CACXQWu6fA%2BT8q-0Z8iqj4WOLyjwuH8MNPWf4F-RATzdSpUNh5Q%40mail.gmail.com.
