From 6e1193c9a2afe78ab96630ac95884e3dcc0fd0e2 Mon Sep 17 00:00:00 2001
From: Fabian Reinartz <fab.reinartz@gmail.com>
Date: Fri, 25 Sep 2015 13:44:00 +0200
Subject: [PATCH] Dispatcher config reloading and restarting

---
 manager/dispatch.go | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/manager/dispatch.go b/manager/dispatch.go
index 363952a1..6cc624dd 100644
--- a/manager/dispatch.go
+++ b/manager/dispatch.go
@@ -17,8 +17,8 @@ const ResolveTimeout = 30 * time.Second
 // Dispatcher sorts incoming alerts into aggregation groups and
 // assigns the correct notifiers to each.
 type Dispatcher struct {
-	routes        Routes
-	alertProvider provider.Alerts
+	routes Routes
+	alerts provider.Alerts
 
 	aggrGroups map[model.Fingerprint]*aggrGroup
 	notifiers  map[string]Notifier
@@ -30,13 +30,8 @@ type Dispatcher struct {
 }
 
 // NewDispatcher returns a new Dispatcher.
-func NewDispatcher(ctx context.Context, state State, notifier Notifier) *Dispatcher {
-	d := &Dispatcher{
-		aggrGroups: map[model.Fingerprint]*aggrGroup{},
-	}
-	d.ctx, d.cancel = context.WithCancel(ctx)
-
-	return d
+func NewDispatcher(ap provider.Alerts) *Dispatcher {
+	return &Dispatcher{alerts: ap}
 }
 
 // ApplyConfig updates the dispatcher to match the new configuration.
@@ -44,6 +39,8 @@ func (d *Dispatcher) ApplyConfig(conf *Config) {
 	d.mtx.Lock()
 	defer d.mtx.Unlock()
 
+	d.Stop()
+
 	d.routes = conf.Routes
 	d.notifiers = map[string]Notifier{}
 
@@ -51,15 +48,26 @@ func (d *Dispatcher) ApplyConfig(conf *Config) {
 	for _, ncfg := range conf.NotificationConfigs {
 		d.notifiers[ncfg.Name] = &LogNotifier{ncfg.Name}
 	}
+
+	go d.Run()
 }
 
 // Run starts dispatching alerts incoming via the updates channel.
-func (d *Dispatcher) Run(updates <-chan *Alert) {
+func (d *Dispatcher) Run() {
 	d.done = make(chan struct{})
+	d.aggrGroups = map[model.Fingerprint]*aggrGroup{}
+
+	d.ctx, d.cancel = context.WithCancel(context.Background())
+
+	updates := d.alertProvider.IterActive()
 
 	defer close(d.done)
 	defer close(updates)
 
+	d.run(updates)
+}
+
+func (d *Dispatcher) run(updates <-chan *Alert) {
 	cleanup := time.Tick(30 * time.Second)
 
 	for {
@@ -74,7 +82,6 @@ func (d *Dispatcher) Run(updates <-chan *Alert) {
 			}
 
 		case <-cleanup:
-			// Cleanup routine.
 			for _, ag := range d.aggrGroups {
 				if ag.empty() {
 					ag.stop()
@@ -109,7 +116,7 @@ func (d *Dispatcher) notifyFunc(dest string) notifyFunc {
 	notifier := d.notifiers[dest]
 
 	return func(ctx context.Context, fp model.Fingerprint) bool {
-		alert := d.alertProvider.Get(fp)
+		alert := d.alerts.Get(fp)
 
 		if err := notifier.Notify(ctx, alert); err != nil {
 			log.Errorf("Notify for %v failed: %s", alert, err)