work with opentelemetry without "http_route" and "http_url" attribute printed

[charzhao]

I use below code to get metrics with OTel:

.WithMetrics(cfg =>
{
cfg.AddAspNetCoreInstrumentation();
cfg.AddHttpClientInstrumentation();
cfg.AddRuntimeInstrumentation();
});
but in the output i did not get http_route attribute as below:

http_client_request_duration_seconds_bucket{http_request_method="GET",http_response_status_code="200",network_protocol_version="1.1",server_address="****.com",url_scheme="https",le="0.5"} 0 1706514537848

Is there any way to make http_route and http_url here?

[NTDV]

Hello! Are there any solutions besides writing your own middleware?

[glennawatson]

This is how the OpenTelemetry HttpClient instrumentation behaves, not a Refit limitation. AddHttpClientInstrumentation does not emit http.route for client spans/metrics, because on the client side there is no server route template - it only knows the actual URL. http.route is a server-side semantic-convention attribute.

What you can do:

Refit attaches its RestMethodInfo (which carries the relative path template) to the outgoing HttpRequestMessage options under HttpRequestMessageOptions.RestMethodInfo. You can read that in the instrumentation's enrich callback and add your own attribute:

cfg.AddHttpClientInstrumentation(o =>
{
    o.EnrichWithHttpRequestMessage = (activity, request) =>
    {
        if (request.Options.TryGetValue(
                new HttpRequestOptionsKey<RestMethodInfo>(HttpRequestMessageOptions.RestMethodInfo),
                out var info))
        {
            activity.SetTag("http.route", info.RelativePath);
        }
    };
});

(Adjust the property name to whatever RestMethodInfo exposes for the template in your version.)

For http.url / the full URL, that is controlled by the instrumentation's semantic-convention version and its URL redaction settings - check the OpenTelemetry.Instrumentation.Http options rather than Refit.

So: no built-in http_route for HTTP client metrics by spec; enrich the activity yourself using Refit's request options if you want it.