chore(aci): add flag to GET OrganizationAlertRuleIndexEndpoint

Author: klochek

src/sentry/features/temporary.py

@@ -463,6 +463,9 @@ def register_temporary_features(manager: FeatureManager) -> None:
     manager.add("organizations:workflow-engine-orgalertruledetails-get", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Enable metric detector limits by plan type
     manager.add("organizations:workflow-engine-metric-detector-limit", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
+    # Use workflow engine exclusively for OrganizationAlertRuleIndexEndpoint.get results.
+    # See src/sentry/workflow_engine/docs/legacy_backport.md for context.
+    manager.add("organizations:workflow-engine-orgalertruleindex-get", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Enable EventUniqueUserFrequencyConditionWithConditions special alert condition
     manager.add("organizations:event-unique-user-frequency-condition-with-conditions", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
     # Enable our logs product (known internally as ourlogs) in UI and backend

src/sentry/incidents/endpoints/organization_alert_rule_index.py

@@ -235,6 +235,10 @@ class AlertRuleFetchMixin(Endpoint):
     Can be used with any endpoint base class (OrganizationEndpoint, ProjectEndpoint, etc).
     """
 
+    # Subclasses may set a per-method granular flag (e.g. for GET) that is OR'd
+    # with the broad workflow-engine-rule-serializers flag.
+    workflow_engine_method_flags: dict[str, str] = {}
+
     def fetch_metric_alerts(
         self,
         request: Request,
@@ -252,8 +256,11 @@ def fetch_metric_alerts(
                 extra={"organization": organization.id},
             )
 
-        use_workflow_engine = features.has(
-            "organizations:workflow-engine-rule-serializers", organization
+        method_flag = self.workflow_engine_method_flags.get(request.method or "")
+        use_workflow_engine = (
+            features.has("organizations:workflow-engine-rule-serializers", organization)
+            or method_flag is not None
+            and features.has(method_flag, organization)
         )
 
         if use_workflow_engine:
@@ -908,6 +915,9 @@ class OrganizationAlertRuleIndexEndpoint(OrganizationAlertRuleBaseEndpoint, Aler
         "POST": ApiPublishStatus.PUBLIC,
     }
     permission_classes = (OrganizationAlertRulePermission,)
+    workflow_engine_method_flags = {
+        "GET": "organizations:workflow-engine-orgalertruleindex-get",
+    }
 
     @extend_schema(
         operation_id="(DEPRECATED) List an Organization's Metric Alert Rules",