From 2269bbc03b75c4734dddb97197e415ec11e309bf Mon Sep 17 00:00:00 2001
From: Ben Ridley <benridley29@gmail.com>
Date: Thu, 28 Sep 2023 15:25:00 +1000
Subject: [PATCH] Fix child routes not inheriting time interval configuration

Fixes a bug in the creation of routes which would mistakenly override parent route config with empty time interval configuration if none were specified on the child.

Signed-off-by: Ben Ridley <benridley29@gmail.com>
---
 dispatch/route.go      | 21 ++++++++------
 dispatch/route_test.go | 62 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+), 8 deletions(-)

diff --git a/dispatch/route.go b/dispatch/route.go
index 4b3673c531..bb0f322e79 100644
--- a/dispatch/route.go
+++ b/dispatch/route.go
@@ -29,12 +29,13 @@ import (
 // DefaultRouteOpts are the defaulting routing options which apply
 // to the root route of a routing tree.
 var DefaultRouteOpts = RouteOpts{
-	GroupWait:         30 * time.Second,
-	GroupInterval:     5 * time.Minute,
-	RepeatInterval:    4 * time.Hour,
-	GroupBy:           map[model.LabelName]struct{}{},
-	GroupByAll:        false,
-	MuteTimeIntervals: []string{},
+	GroupWait:           30 * time.Second,
+	GroupInterval:       5 * time.Minute,
+	RepeatInterval:      4 * time.Hour,
+	GroupBy:             map[model.LabelName]struct{}{},
+	GroupByAll:          false,
+	MuteTimeIntervals:   []string{},
+	ActiveTimeIntervals: []string{},
 }
 
 // A Route is a node that contains definitions of how to handle alerts.
@@ -117,8 +118,12 @@ func NewRoute(cr *config.Route, parent *Route) *Route {
 
 	sort.Sort(matchers)
 
-	opts.MuteTimeIntervals = cr.MuteTimeIntervals
-	opts.ActiveTimeIntervals = cr.ActiveTimeIntervals
+	if len(cr.MuteTimeIntervals) != 0 {
+		opts.MuteTimeIntervals = cr.MuteTimeIntervals
+	}
+	if len(cr.ActiveTimeIntervals) != 0 {
+		opts.ActiveTimeIntervals = cr.ActiveTimeIntervals
+	}
 
 	route := &Route{
 		parent:    parent,
diff --git a/dispatch/route_test.go b/dispatch/route_test.go
index e633ae5f6f..c0a036238c 100644
--- a/dispatch/route_test.go
+++ b/dispatch/route_test.go
@@ -383,6 +383,68 @@ routes:
 	require.Equal(t, child2.RouteOpts.GroupByAll, false)
 }
 
+func TestInheritParentMuteTimeIntervals(t *testing.T) {
+	in := `
+routes:
+- match:
+    env: 'parent'
+  group_by: ['...']
+  mute_time_intervals: ['weekend_mute']
+
+  routes:
+  - match:
+      env: 'child1'
+
+  - match:
+      env: 'child2'
+    mute_time_intervals: ['override_mute']
+`
+
+	var ctree config.Route
+	if err := yaml.UnmarshalStrict([]byte(in), &ctree); err != nil {
+		t.Fatal(err)
+	}
+
+	tree := NewRoute(&ctree, nil)
+	parent := tree.Routes[0]
+	child1 := parent.Routes[0]
+	child2 := parent.Routes[1]
+	require.Equal(t, []string{"weekend_mute"}, parent.RouteOpts.MuteTimeIntervals)
+	require.Equal(t, []string{"weekend_mute"}, child1.RouteOpts.MuteTimeIntervals)
+	require.Equal(t, []string{"override_mute"}, child2.RouteOpts.MuteTimeIntervals)
+}
+
+func TestInheritParentActiveTimeIntervals(t *testing.T) {
+	in := `
+routes:
+- match:
+    env: 'parent'
+  group_by: ['...']
+  active_time_intervals: ['weekend_active']
+
+  routes:
+  - match:
+      env: 'child1'
+
+  - match:
+      env: 'child2'
+    active_time_intervals: ['override_active']
+`
+
+	var ctree config.Route
+	if err := yaml.UnmarshalStrict([]byte(in), &ctree); err != nil {
+		t.Fatal(err)
+	}
+
+	tree := NewRoute(&ctree, nil)
+	parent := tree.Routes[0]
+	child1 := parent.Routes[0]
+	child2 := parent.Routes[1]
+	require.Equal(t, []string{"weekend_active"}, parent.RouteOpts.ActiveTimeIntervals)
+	require.Equal(t, []string{"weekend_active"}, child1.RouteOpts.ActiveTimeIntervals)
+	require.Equal(t, []string{"override_active"}, child2.RouteOpts.ActiveTimeIntervals)
+}
+
 func TestRouteMatchers(t *testing.T) {
 	in := `
 receiver: 'notify-def'