Hello! I’ve been playing with the OpenTelemetry module for the Tracing filters and wanted to have an easy way to name the server spans for each different route. Rather than pass a spanNamer – which would have the effect of having my naming logic separated from the routing definition, I extended the routing DSL a little bit to get this:

fun endpoints() = "/orders" bind POST to routes(
            "/create" bind ::createOrder named "Create Order",
            "/submit" bind ::submitOrder named "Submit Order",
    )

object SpanNameFilter {
    operator fun invoke(name: String) = Filter { next ->
        { req ->
            Span.current().updateName(name)
            next(req)
        }
    }
}

infix fun RoutingHttpHandler.named(name: String) = SpanNameFilter(name).then(this)

Wondered if this might be something you’d be interested in adding to the opentelemetry module in some form or other? Or is there a different way of doing this you’d recommend? Would a more general ability to name RoutingHttpHandlers be useful?

Hi, I don’t use (sadly) OT, but I see in the Server et Client Filter the span name being a function. So I guess you can set your own fonction to set the spanNamer from the request… the full URI is not always the best as you say it can have ids. but it’s a simple default, up to you to come up with something custom to your endpoint:

fun ServerFilters.OpenTelemetryTracing(
    openTelemetry: OpenTelemetry = GlobalOpenTelemetry.get(),
    spanNamer: (Request) -> String = { it.uri.toString() },
    error: (Request, Throwable) -> String = { _, t -> t.localizedMessage },
): Filter