feat(spans): extract country code into spans (#3911)

work towards getsentry/sentry#75230

This PR adds country_code as an indexed span tag. Eventually we would
like to create regional metrics, but we have to make a product decision
on whether we want country based metrics, or larger region metrics (ex.
continent). There are also ~200 countries, which could be high
cardinality wise, but at least we have a known limit (lmk if you have
thoughts on this!)

Author: DominikB2014

CHANGELOG.md

@@ -17,6 +17,7 @@
 - Collect SDK information in profile chunks. ([#3882](https://github.com/getsentry/relay/pull/3882))
 - Introduce `trim = "disabled"` type attribute to prevent trimming of spans. ([#3877](https://github.com/getsentry/relay/pull/3877))
 - Make the tcp listen backlog configurable and raise the default to 1024. ([#3899](https://github.com/getsentry/relay/pull/3899))
+- Extract `user.geo.country_code` into span indexed. ([#3911](https://github.com/getsentry/relay/pull/3911))
 
 ## 24.7.1
 
@@ -48,6 +49,7 @@
 - Only transfer valid profile ids. ([#3809](https://github.com/getsentry/relay/pull/3809))
 
 **Features**:
+
 - Allow list for excluding certain host/IPs from scrubbing in spans. ([#3813](https://github.com/getsentry/relay/pull/3813))
 
 **Internal**:

relay-event-normalization/src/normalize/span/tag_extraction.rs

@@ -85,6 +85,7 @@ pub enum SpanTagKey {
     ThreadName,
     ThreadId,
     ProfilerId,
+    UserCountryCode,
 }
 
 impl SpanTagKey {
@@ -98,6 +99,7 @@ impl SpanTagKey {
             SpanTagKey::UserID => "user.id",
             SpanTagKey::UserUsername => "user.username",
             SpanTagKey::UserEmail => "user.email",
+            SpanTagKey::UserCountryCode => "user.geo.country_code",
             SpanTagKey::Environment => "environment",
             SpanTagKey::Transaction => "transaction",
             SpanTagKey::TransactionMethod => "transaction.method",
@@ -308,6 +310,9 @@ fn extract_shared_tags(event: &Event) -> BTreeMap<SpanTagKey, String> {
         if let Some(user_email) = user.email.value() {
             tags.insert(SpanTagKey::UserEmail, user_email.clone());
         }
+        if let Some(country_code) = user.geo.value().and_then(|geo| geo.country_code.value()) {
+            tags.insert(SpanTagKey::UserCountryCode, country_code.to_owned());
+        }
     }
 
     if let Some(environment) = event.environment.as_str() {
@@ -2537,7 +2542,10 @@ LIMIT 1
                 "user": {
                     "id": "1",
                     "email": "[email protected]",
-                    "username": "admin"
+                    "username": "admin",
+                    "geo": {
+                        "country_code": "US"
+                    }
                 },
                 "spans": [
                     {
@@ -2571,6 +2579,7 @@ LIMIT 1
             get_value!(span.sentry_tags["user.email"]!),
             "[email protected]"
         );
+        assert_eq!(get_value!(span.sentry_tags["user.geo.country_code"]!), "US");
     }
 
     #[test]