Merge pull request #1258 from aledbf/fix-1233

[nginx-ingress-controller]: Avoid sync without a reachable master

ingress/controllers/nginx/controller.go

@@ -420,13 +420,17 @@ func (lbc *loadBalancerController) sync(key string) error {
 		return fmt.Errorf("deferring sync till endpoints controller has synced")
 	}
 
-	var cfg *api.ConfigMap
-
-	ns, name, _ := parseNsName(lbc.nxgConfigMap)
-	cfg, err := lbc.getConfigMap(ns, name)
-	if err != nil {
-		glog.V(3).Infof("unexpected error searching configmap %v: %v", lbc.nxgConfigMap, err)
-		cfg = &api.ConfigMap{}
+	// by default no custom configuration configmap
+	cfg := &api.ConfigMap{}
+
+	if lbc.nxgConfigMap != "" {
+		// Search for custom configmap (defined in main args)
+		var err error
+		ns, name, _ := parseNsName(lbc.nxgConfigMap)
+		cfg, err = lbc.getConfigMap(ns, name)
+		if err != nil {
+			return fmt.Errorf("unexpected error searching configmap %v: %v", lbc.nxgConfigMap, err)
+		}
 	}
 
 	ngxConfig := lbc.nginx.ReadConfig(cfg)

ingress/controllers/nginx/main.go

@@ -130,6 +130,13 @@ func main() {
 	}
 	glog.Infof("Validated %v as the default backend", *defaultSvc)
 
+	if *nxgConfigMap != "" {
+		_, _, err := parseNsName(*nxgConfigMap)
+		if err != nil {
+			glog.Fatalf("configmap error: %v", err)
+		}
+	}
+
 	lbc, err := newLoadBalancerController(kubeClient, *resyncPeriod, *defaultSvc, *watchNamespace, *nxgConfigMap, *tcpConfigMapName, *udpConfigMapName, runtimePodInfo)
 	if err != nil {
 		glog.Fatalf("%v", err)