On Thu, 23 Apr 2020 at 21:08, Chris Taylor < [email protected]> wrote:
> > > 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. > It sounds then like you'd curry the registry with the relevant labels before passing it in then. Brian > > >> >> 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 >> > -- 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/CAHJKeLqB%2B6Gkd5XWpH5V5Hdth7b1m58CscjP9GYqJcUL%2Bqk5zA%40mail.gmail.com.
