Fix `close a closed channel` panic on shutdown

pkg/controller/controller.go

@@ -29,6 +29,7 @@
 package controller
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"time"
@@ -109,7 +110,8 @@ type IngressController struct {
 	informers   *infrmrs
 	listers     *Listers
 	nsQs        *NamespaceQueues
-	stopCh      chan struct{}
+	ctx         context.Context
+	cancel      context.CancelFunc
 	recorder    record.EventRecorder
 }
 
@@ -135,7 +137,6 @@ func NewIngressController(
 	ingc := IngressController{
 		log:    log,
 		client: kubeClient,
-		stopCh: make(chan struct{}),
 	}
 
 	InitMetrics()
@@ -323,15 +324,16 @@ func (ingc *IngressController) updateObj(old, new interface{}) {
 // the controller is ready (after informers have launched).
 func (ingc *IngressController) Run(readyFile string, metricsPort uint16) {
 	defer utilruntime.HandleCrash()
-	defer ingc.nsQs.Stop()
+
+	ingc.ctx, ingc.cancel = context.WithCancel(context.Background())
 
 	ingc.log.Info("Launching informers")
-	go ingc.informers.ing.Run(ingc.stopCh)
-	go ingc.informers.svc.Run(ingc.stopCh)
-	go ingc.informers.endp.Run(ingc.stopCh)
-	go ingc.informers.secr.Run(ingc.stopCh)
-	go ingc.informers.vcfg.Run(ingc.stopCh)
-	go ingc.informers.bcfg.Run(ingc.stopCh)
+	go ingc.informers.ing.Run(ingc.ctx.Done())
+	go ingc.informers.svc.Run(ingc.ctx.Done())
+	go ingc.informers.endp.Run(ingc.ctx.Done())
+	go ingc.informers.secr.Run(ingc.ctx.Done())
+	go ingc.informers.vcfg.Run(ingc.ctx.Done())
+	go ingc.informers.bcfg.Run(ingc.ctx.Done())
 
 	ingc.log.Infof("Starting metrics listener at port %d", metricsPort)
 	go ServeMetrics(ingc.log, metricsPort)
@@ -355,7 +357,7 @@ func (ingc *IngressController) Run(readyFile string, metricsPort uint16) {
 	}
 
 	ingc.log.Info("Waiting for caches to sync")
-	if ok := cache.WaitForCacheSync(ingc.stopCh,
+	if ok := cache.WaitForCacheSync(ingc.ctx.Done(),
 		ingc.informers.ing.HasSynced,
 		ingc.informers.svc.HasSynced,
 		ingc.informers.endp.HasSynced,
@@ -369,16 +371,16 @@ func (ingc *IngressController) Run(readyFile string, metricsPort uint16) {
 	}
 
 	ingc.log.Info("Caches synced, running workers")
-	go wait.Until(ingc.nsQs.Run, time.Second, ingc.stopCh)
+	go wait.Until(ingc.nsQs.Run, time.Second, ingc.ctx.Done())
 
-	<-ingc.stopCh
+	<-ingc.ctx.Done()
+	ingc.log.Info("Stop received for Controller")
 }
 
 // Stop the Ingress controller -- signal the workers to stop.
 func (ingc *IngressController) Stop() {
-	ingc.stopCh <- struct{}{}
 	ingc.log.Info("Shutting down workers")
-	close(ingc.stopCh)
-	<-ingc.nsQs.DoneChan
+	ingc.cancel()
+	ingc.nsQs.Stop()
 	ingc.log.Info("Controller exiting")
 }

pkg/controller/worker.go

@@ -269,7 +269,6 @@ func (worker *NamespaceWorker) work() {
 // responsible for each namespace.
 type NamespaceQueues struct {
 	Queue       workqueue.RateLimitingInterface
-	DoneChan    chan struct{}
 	ingClass    string
 	log         *logrus.Logger
 	vController *varnish.Controller
@@ -302,7 +301,6 @@ func NewNamespaceQueues(
 		workqueue.DefaultControllerRateLimiter(), "_ALL_")
 	return &NamespaceQueues{
 		Queue:       q,
-		DoneChan:    make(chan struct{}),
 		log:         log,
 		ingClass:    ingClass,
 		vController: vController,
@@ -393,5 +391,4 @@ func (qs *NamespaceQueues) Stop() {
 	}
 	qs.log.Info("Waiting for workers to shut down")
 	qs.wg.Wait()
-	close(qs.DoneChan)
 }