fix(dynamic-config): Expose metric extraction to all Relays (#2440)

Metric extraction configuration was not added to `LimitedProjectConfig`.
For this reason, external Relays would not see specs for on-demand
metric extraction. All traffic ingested through Relay PoPs or external
Relays therefore was missing on-demand metrics.

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - Filter out exceptions originating in Safari extensions. ([#2408](https://github.com/getsentry/relay/pull/2408))
 - Fixes the `TraceContext.status` not being defaulted to `unknown` before the new metrics extraction pipeline. ([#2436](https://github.com/getsentry/relay/pull/2436))
+- Support on-demand metrics for alerts and widgets in external Relays. ([#2440](https://github.com/getsentry/relay/pull/2440))
 
 ## 23.8.0
 

relay-dynamic-config/src/project.rs

@@ -146,6 +146,8 @@ pub struct LimitedProjectConfig {
     pub session_metrics: SessionMetricsConfig,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub transaction_metrics: Option<ErrorBoundary<TransactionMetricsConfig>>,
+    #[serde(default, skip_serializing_if = "skip_metrics_extraction")]
+    pub metric_extraction: ErrorBoundary<MetricExtractionConfig>,
     #[serde(skip_serializing_if = "Vec::is_empty")]
     pub metric_conditional_tagging: Vec<TaggingRule>,
     #[serde(skip_serializing_if = "BTreeSet::is_empty")]

tests/integration/test_metrics.py

@@ -1231,7 +1231,8 @@ def test_generic_metric_extraction(mini_sentry, relay):
     transaction["timestamp"] = timestamp.isoformat()
     transaction["start_timestamp"] = (timestamp - timedelta(seconds=2)).isoformat()
 
-    relay = relay(mini_sentry, options=TEST_CONFIG)
+    # Explicitly test a chain of Relays
+    relay = relay(relay(mini_sentry, options=TEST_CONFIG), options=TEST_CONFIG)
     relay.send_transaction(PROJECT_ID, transaction)
 
     envelope = mini_sentry.captured_events.get(timeout=3)