Controller name as metric label as option with .UsePrometheusRequestDurations()

[billpieper]

We are migrating our applications from Prometheus-net to Prometheus.Client.

Prometheus-net had an extension method to IApplicationBuilder called UseHttpMetrics(). With the implementation in Prometheus.Client.HttpRequestDurations, I have been unable to identify a way to incorporate the controller name as a label in the metric. We really need this as if we use the path instead -- we end up with significant label explosion due to many parameters that are inorporated into our api route paths.

Is there an existing way to get 'Controller' name as a label? and if not, is this something that could be added?

[sanych-sun]

Try to use "UseRouteName" it could resolve route name/pattern instead of raw path.

[phnx47]

@billpieper "UseRouteName" is working for you?

[billpieper]

No, unfortunately this does not meet our needs. We have [Route()] attributes decorating our controllers at a class level classes like this [Route("api/[controller]")]. Then at methods where we may need to take in a parameter in the route we will have a route attribute defined there too -- something like this: [Route("{id}")]

The UseRouteName option ends up setting a label that doesn't let us distinguish between our controllers and routes.

I ended up forking and adding the option to include a label for Controller and for Action. This mimics what was available in the old sdk. Additionally, I added an option to enable the metric to include the Timestamp Is this something you would consider adding and/or accepting a PR to include?

[phnx47]

@billpieper Yes, raise your PR, if work is already done, please. I want to create options to add Controller and Action to labels, but by default without this, something like this:

app.UsePrometheusRequestDurations(q =>
{
  q.IncludeConroller = true;
  q.IncludeAction = true;
});

[phnx47]

Published v3.5.0