From 2188516a21be660c4080884d2c937d9cbfcb8047 Mon Sep 17 00:00:00 2001
From: Julien Duchesne <julien.duchesne@grafana.com>
Date: Tue, 26 Mar 2024 12:31:59 -0400
Subject: [PATCH] Alerting: Fix receiver inheritance when provisioning a
 notification policy (#82007)

Terraform Issue: grafana/terraform-provider-grafana#1007
Nested routes should be allowed to inherit the contact point from the root (or direct parent) route but this fails in the provisioning API (it works in the UI)
---
 .../provisioning/notification_policies.go     |  1 +
 .../notification_policies_test.go             | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/pkg/services/ngalert/provisioning/notification_policies.go b/pkg/services/ngalert/provisioning/notification_policies.go
index 629a5717b31..eeea63c4f29 100644
--- a/pkg/services/ngalert/provisioning/notification_policies.go
+++ b/pkg/services/ngalert/provisioning/notification_policies.go
@@ -70,6 +70,7 @@ func (nps *NotificationPolicyService) UpdatePolicyTree(ctx context.Context, orgI
 		return err
 	}
 
+	receivers[""] = struct{}{} // Allow empty receiver (inheriting from parent)
 	err = tree.ValidateReceivers(receivers)
 	if err != nil {
 		return fmt.Errorf("%w: %s", ErrValidation, err.Error())
diff --git a/pkg/services/ngalert/provisioning/notification_policies_test.go b/pkg/services/ngalert/provisioning/notification_policies_test.go
index 6202848606d..95b319e5b2d 100644
--- a/pkg/services/ngalert/provisioning/notification_policies_test.go
+++ b/pkg/services/ngalert/provisioning/notification_policies_test.go
@@ -92,6 +92,31 @@ func TestNotificationPolicyService(t *testing.T) {
 		require.Equal(t, "slack receiver", updated.Receiver)
 	})
 
+	t.Run("no root receiver will error", func(t *testing.T) {
+		sut := createNotificationPolicyServiceSut()
+
+		newRoute := createTestRoutingTree()
+		newRoute.Receiver = ""
+		newRoute.Routes = append(newRoute.Routes, &definitions.Route{
+			Receiver: "",
+		})
+
+		err := sut.UpdatePolicyTree(context.Background(), 1, newRoute, models.ProvenanceNone)
+		require.EqualError(t, err, "invalid object specification: root route must specify a default receiver")
+	})
+
+	t.Run("allow receiver inheritance", func(t *testing.T) {
+		sut := createNotificationPolicyServiceSut()
+
+		newRoute := createTestRoutingTree()
+		newRoute.Routes = append(newRoute.Routes, &definitions.Route{
+			Receiver: "",
+		})
+
+		err := sut.UpdatePolicyTree(context.Background(), 1, newRoute, models.ProvenanceNone)
+		require.NoError(t, err)
+	})
+
 	t.Run("not existing receiver reference will error", func(t *testing.T) {
 		sut := createNotificationPolicyServiceSut()