Treat Activity.TagObjects "http.response.status_code" as a special value to import via OTel

[BlairMcClelland]

Problem Statement

Inspired by the discussion here -

Thanks to Coby from support for pointing me to this discussion.

We attribute special meaning to some TagObjects based on the Key in the KVP. For example, we know the URL is important in ASP.NET Core apps:

sentry-dotnet/src/Sentry.OpenTelemetry/SentrySpanProcessor.cs

Line 195 in 9b29d1f

var url = attributes.UrlFullAttribute();

The key is really the only thing that provide some hint... but we can't use this for custom tags that you've defined.

If you wanted to make some specific TagObjects searchable, you could potentially write some custom logic in the SetBeforeSendTransaction callback to copy these across.

Originally posted by @jamescrosswell in #4043

This got me wondering if there could be the same special treatment for http.response.status_code ?

This is the only OpenTelemetry attribute brought through by default with .AddAspNetCoreInstrumentation() that I cannot find in a more visible space on the traces page and would be a very welcome addition.

Furthermore, as per the above discussion I did explore using SetBeforeSendTransaction and SentrySdk which worked as expected, however having the response code extraction built in by default might be a welcome feature for the community?

o.SetBeforeSendTransaction((transaction, hint) =>
{
    var act = Activity.Current;
    var statusCode = act?.TagObjects.FirstOrDefault(x => x.Key == "http.response.status_code");
    if (statusCode is not null && statusCode.HasValue)
        transaction.SetTag("http.response.status_code", statusCode.Value.ToString());

    return transaction;
});

SentrySdk.ConfigureScope(scope =>
        {
            scope.SetTag("ResponseStatusCode", context.Response.StatusCode.ToString());
        });

Solution Brainstorm

No response

[Flash0ver]

Thank you, @BlairMcClelland, for the request and all the detailed context provided.
I'm new to the project and not too familiar with the OTel specs just yet.
I'll dive into #2453 and pick @jamescrosswell's brain. I'll get back to you (~1 week) when I'm more confident with the subject.

[cobyeastwood183]

https://sentry.zendesk.com/agent/tickets/148533

[jamescrosswell]

@Flash0ver for reference, lots of info in the description for the original PR introducing OpenTelemetry:

• Feature: Open Telemetry Support #2453

Also worth reading the developer docs on contexts (and the Response Context in particular).

And the docs on searchable properties...

@BlairMcClelland are you wanting to seach/filter events based on the response code? Or is it just about visibility (the information is already present in the Otel attributes in the screenshot that you sent through).

[BlairMcClelland]

Hi James, we would like the ability to search and filter by status code