Merge pull request kubernetes-retired#1336 from aledbf/skip-ingress-r…

…ules

[nginx-ingress-controller]: Add annotation to skip ingress rule

controllers/nginx/README.md

@@ -17,6 +17,7 @@ This is a nginx Ingress controller that uses [ConfigMap](https://github.com/kube
 * [Proxy Protocol](#proxy-protocol)
 * [NGINX customization](configuration.md)
 * [NGINX status page](#nginx-status-page)
+* [Disabling NGINX ingress controller](#disabling-nginx-ingress-controller)
 * [Debug & Troubleshooting](#troubleshooting)
 * [Limitations](#limitations)
 * [NGINX Notes](#nginx-notes)
@@ -233,6 +234,10 @@ Please check the example `example/rc-default.yaml`
 
 To extract the information in JSON format the module provides a custom URL: `/nginx_status/format/json`
 
+### Disabling NGINX ingress controller
+
+Setting the annotation `kubernetes.io/ingress.class` to any value other than "nginx" or the empty string, will force the NGINX Ingress controller to ignore your Ingress. Do this if you wish to use one of the other Ingress controllers at the same time as the NGINX controller.
+
 
 ### Debug & Troubleshooting
 

controllers/nginx/controller.go

@@ -150,16 +150,28 @@ func newLoadBalancerController(kubeClient *client.Client, resyncPeriod time.Dura
 	ingEventHandler := framework.ResourceEventHandlerFuncs{
 		AddFunc: func(obj interface{}) {
 			addIng := obj.(*extensions.Ingress)
+			if !isNGINXIngress(addIng) {
+				glog.Infof("Ignoring add for ingress %v based on annotation %v", addIng.Name, ingressClassKey)
+				return
+			}
 			lbc.recorder.Eventf(addIng, api.EventTypeNormal, "CREATE", fmt.Sprintf("%s/%s", addIng.Namespace, addIng.Name))
 			lbc.ingQueue.enqueue(obj)
 			lbc.syncQueue.enqueue(obj)
 		},
 		DeleteFunc: func(obj interface{}) {
-			upIng := obj.(*extensions.Ingress)
-			lbc.recorder.Eventf(upIng, api.EventTypeNormal, "DELETE", fmt.Sprintf("%s/%s", upIng.Namespace, upIng.Name))
+			delIng := obj.(*extensions.Ingress)
+			if !isNGINXIngress(delIng) {
+				glog.Infof("Ignoring add for ingress %v based on annotation %v", delIng.Name, ingressClassKey)
+				return
+			}
+			lbc.recorder.Eventf(delIng, api.EventTypeNormal, "DELETE", fmt.Sprintf("%s/%s", delIng.Namespace, delIng.Name))
 			lbc.syncQueue.enqueue(obj)
 		},
 		UpdateFunc: func(old, cur interface{}) {
+			curIng := cur.(*extensions.Ingress)
+			if !isNGINXIngress(curIng) {
+				return
+			}
 			if !reflect.DeepEqual(old, cur) {
 				upIng := cur.(*extensions.Ingress)
 				lbc.recorder.Eventf(upIng, api.EventTypeNormal, "UPDATE", fmt.Sprintf("%s/%s", upIng.Namespace, upIng.Name))

controllers/nginx/utils.go

@@ -26,6 +26,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	apierrs "k8s.io/kubernetes/pkg/api/errors"
+	"k8s.io/kubernetes/pkg/apis/extensions"
 	"k8s.io/kubernetes/pkg/client/cache"
 	"k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/util/wait"
@@ -246,3 +247,29 @@ func waitForPodCondition(kubeClient *unversioned.Client, ns, podName string, con
 		return false, nil
 	})
 }
+
+// ingAnnotations represents Ingress annotations.
+type ingAnnotations map[string]string
+
+const (
+	// ingressClassKey picks a specific "class" for the Ingress. The controller
+	// only processes Ingresses with this annotation either unset, or set
+	// to either nginxIngressClass or the empty string.
+	ingressClassKey   = "kubernetes.io/ingress.class"
+	nginxIngressClass = "nginx"
+)
+
+func (ing ingAnnotations) ingressClass() string {
+	val, ok := ing[ingressClassKey]
+	if !ok {
+		return ""
+	}
+	return val
+}
+
+// isNGINXIngress returns true if the given Ingress either doesn't specify the
+// ingress.class annotation, or it's set to "nginx".
+func isNGINXIngress(ing *extensions.Ingress) bool {
+	class := ingAnnotations(ing.ObjectMeta.Annotations).ingressClass()
+	return class == "" || class == nginxIngressClass
+}