Get matched route information

[cortopy]

Is your feature request related to a problem? Please describe.

When a Request is processed, I need to log which route is being handled. The Opentelemetry definition of route is very handy:

The matched route, that is, the path template in the format used by the respective server framework.

And they give examples like: /users/:userID?, {controller}/{action}/{id?}

I need this because:

• When searching log records, I don't want to search for /user/123 but /user/<id> since I may want to see requests for that route.
• Some observability providers like Grafana cloud charge per cardinality, and logging requests with variable parameters can be very expensive.
• Due to privacy legistlation like GDPR, identifiable information like user ids need to be removed or masked. Having a way to know if the Request has been matched with a route that has parameters would be great.
• Opentelemetry defines http.route as an established convention to log which server route a given request has been matched with.

Describe the solution you'd like
It'd be amazing if Request or Response had something like:

struct RouteInformation {
   path: &str
}

impl RouteInformation {
  pub fn masked_uri() -> String {
     // Some logic to replace parameters with something lkike ****
  }
}

struct Request {
   route: RouteInformation,
   ...
}

#[async_trait]
impl Handler for Logger {
    async fn handle(
        &self,
        req: &mut Request,
        depot: &mut Depot,
        res: &mut Response,
        ctrl: &mut FlowCtrl,
    ) {
        let span = info_span!(
            "Request",
            // Instead of: path = %req.uri(),
            url.path = %req.route.masked(),
            http.route = %req.route.path(),
        );

        async move {
            let now = Instant::now();
            ctrl.call_next(req, depot, res).await;
            let duration = now.elapsed();

            let status = res.status_code.unwrap_or(match &res.body {
                ResBody::None => StatusCode::NOT_FOUND,
                ResBody::Error(e) => e.code,
                _ => StatusCode::OK,
            });
            info!(
                http.response.status_code = %status,
                http.duration = ?duration,
                "Response"
            );
        }
        .instrument(span)
        .await
    }
}

Describe alternatives you've considered
Request doesn't provide information about routes so it would be some laborious manual process for each known route. This would be prone to error.

[chrislearn]

Any other web framework has this feature?

[immno]

I see that Axum seems to have achieved it.
doc
axum issues