Clear out obsolete code for general shutdown.

The error channel for the Varnish controller was never used.
The Varnish controller uses a WaitGroup to wait for any running
admin interactions with Varnish instances to complete before
shutting down.

Closes #6

cmd/main.go

@@ -202,9 +202,8 @@ func main() {
 		os.Exit(-1)
 	}
 	vController.EvtGenerator(ingController)
-	varnishDone := make(chan error, 1)
-	go handleTermination(log, ingController, vController, varnishDone)
-	vController.Start(varnishDone)
+	go handleTermination(log, ingController, vController)
+	vController.Start()
 	informerFactory.Start(informerStop)
 	ingController.Run(*readyfileF, uint16(*metricsPortF))
 }
@@ -212,28 +211,13 @@ func main() {
 func handleTermination(
 	log *logrus.Logger,
 	ingc *controller.IngressController,
-	vc *varnish.VarnishController,
-	varnishDone chan error) {
+	vc *varnish.VarnishController) {
 
 	signalChan := make(chan os.Signal, 1)
 	signal.Notify(signalChan, syscall.SIGTERM, syscall.SIGINT)
 
-	exitStatus := 0
-	exited := false
-
-	select {
-	case err := <-varnishDone:
-		if err != nil {
-			log.Error("varnish controller exited with an error:",
-				err)
-			exitStatus = 1
-		} else {
-			log.Info("varnish controller exited successfully")
-		}
-		exited = true
-	case sig := <-signalChan:
-		log.Infof("Received signal (%s), shutting down", sig.String())
-	}
+	sig := <-signalChan
+	log.Infof("Received signal (%s), shutting down", sig.String())
 
 	log.Info("Shutting down the ingress controller")
 	ingc.Stop()
@@ -241,11 +225,9 @@ func handleTermination(
 	log.Info("Shutting down informers")
 	informerStop <- struct{}{}
 
-	if !exited {
-		log.Info("Shutting down the Varnish controller")
-		vc.Quit()
-	}
+	log.Info("Shutting down the Varnish controller")
+	vc.Quit()
 
-	log.Info("Exiting with a status:", exitStatus)
-	os.Exit(exitStatus)
+	log.Info("Exiting")
+	os.Exit(0)
 }

pkg/varnish/monitor.go

@@ -88,6 +88,8 @@ func (vc *VarnishController) checkInst(svc string, inst *varnishInst) bool {
 	}
 	inst.admMtx.Lock()
 	defer inst.admMtx.Unlock()
+	vc.wg.Add(1)
+	defer vc.wg.Done()
 
 	timer := prometheus.NewTimer(metrics.connectLatency)
 	adm, err := admin.Dial(inst.addr, *inst.admSecret, admTimeout)

pkg/varnish/varnish.go

@@ -151,7 +151,7 @@ type VarnishController struct {
 	svcEvt   interfaces.SvcEventGenerator
 	svcs     map[string]*varnishSvc
 	secrets  map[string]*[]byte
-	errChan  chan error
+	wg       *sync.WaitGroup
 	monIntvl time.Duration
 }
 
@@ -183,6 +183,7 @@ func NewVarnishController(
 		secrets:  make(map[string]*[]byte),
 		log:      log,
 		monIntvl: monIntvl,
+		wg:       new(sync.WaitGroup),
 	}, nil
 }
 
@@ -195,9 +196,7 @@ func (vc *VarnishController) EvtGenerator(svcEvt interfaces.SvcEventGenerator) {
 
 // Start initiates the Varnish controller and starts the monitor
 // goroutine.
-func (vc *VarnishController) Start(errChan chan error) {
-	vc.errChan = errChan
-	vc.log.Info("Starting Varnish controller")
+func (vc *VarnishController) Start() {
 	fmt.Printf("Varnish controller logging at level: %s\n", vc.log.Level)
 	go vc.monitor(vc.monIntvl)
 }
@@ -212,6 +211,8 @@ func (vc *VarnishController) updateVarnishInstance(inst *varnishInst,
 	}
 	inst.admMtx.Lock()
 	defer inst.admMtx.Unlock()
+	vc.wg.Add(1)
+	defer vc.wg.Done()
 
 	vc.log.Tracef("Connect to %s, timeout=%v", inst.addr, admTimeout)
 	timer := prometheus.NewTimer(metrics.connectLatency)
@@ -359,6 +360,8 @@ func (vc *VarnishController) setCfgLabel(inst *varnishInst,
 	metrics := getInstanceMetrics(inst.addr)
 	inst.admMtx.Lock()
 	defer inst.admMtx.Unlock()
+	vc.wg.Add(1)
+	defer vc.wg.Done()
 
 	vc.log.Tracef("Connect to %s, timeout=%v", inst.addr, admTimeout)
 	timer := prometheus.NewTimer(metrics.connectLatency)
@@ -753,5 +756,7 @@ func (vc *VarnishController) DeleteAdmSecret(name string) {
 
 // Quit stops the Varnish controller.
 func (vc *VarnishController) Quit() {
-	vc.errChan <- nil
+	vc.log.Info("Wait for admin interactions with Varnish instances to " +
+		"finish")
+	vc.wg.Wait()
 }