Replaced event queue based watching resources in router with shared i…

…nformers

- Custom shared informer is used to leverage namespace, label and field filtering.
  (Auto generated shared informer does not allow this)
- Listing resources by shared informers doesn't order by resource version/creation time.
  So custom lister for routes is used to order the route list by creation time and this
  will allow oldest route to be processed before new route to claim the host name.
- Synchronization with the informer queue and cache is a bit difficult as the cache could
  have newer changes than what was pushed on to the queue. Luckily We only care about the
  first sync to avoid 503 status code for routes.
- Handling first sync: Initially all existing items in the cache are pushed as ADD events,
  so router will get at least one event for the item even if the  cache is new (MODIFIED or
  DELETED event on existing item). Using this info and maintaining consumed count, first
  router sync op is performed.
- Subsequent router syncs rely on informer syncing sate and uses rate limiter to coalesce changes.

pkg/cmd/infra/router/router.go

@@ -19,7 +19,7 @@ import (
 	"github.com/openshift/origin/pkg/cmd/util/variable"
 	projectclient "github.com/openshift/origin/pkg/project/generated/internalclientset/typed/project/internalversion"
 	routeapi "github.com/openshift/origin/pkg/route/apis/route"
-	routeclient "github.com/openshift/origin/pkg/route/generated/internalclientset/typed/route/internalversion"
+	routeinternalclientset "github.com/openshift/origin/pkg/route/generated/internalclientset"
 	"github.com/openshift/origin/pkg/router/controller"
 	controllerfactory "github.com/openshift/origin/pkg/router/controller/factory"
 )
@@ -33,9 +33,7 @@ type RouterSelection struct {
 	OverrideHostname bool
 
 	LabelSelector string
-	Labels        labels.Selector
 	FieldSelector string
-	Fields        fields.Selector
 
 	Namespace              string
 	NamespaceLabelSelector string
@@ -165,23 +163,15 @@ func (o *RouterSelection) Complete() error {
 		return fmt.Errorf("--override-hostname requires that --hostname-template be specified")
 	}
 	if len(o.LabelSelector) > 0 {
-		s, err := labels.Parse(o.LabelSelector)
-		if err != nil {
+		if _, err := labels.Parse(o.LabelSelector); err != nil {
 			return fmt.Errorf("label selector is not valid: %v", err)
 		}
-		o.Labels = s
-	} else {
-		o.Labels = labels.Everything()
 	}
 
 	if len(o.FieldSelector) > 0 {
-		s, err := fields.ParseSelector(o.FieldSelector)
-		if err != nil {
+		if _, err := fields.ParseSelector(o.FieldSelector); err != nil {
 			return fmt.Errorf("field selector is not valid: %v", err)
 		}
-		o.Fields = s
-	} else {
-		o.Fields = fields.Everything()
 	}
 
 	if len(o.ProjectLabelSelector) > 0 {
@@ -221,10 +211,10 @@ func (o *RouterSelection) Complete() error {
 }
 
 // NewFactory initializes a factory that will watch the requested routes
-func (o *RouterSelection) NewFactory(routeclient routeclient.RoutesGetter, projectclient projectclient.ProjectResourceInterface, kc kclientset.Interface) *controllerfactory.RouterControllerFactory {
+func (o *RouterSelection) NewFactory(routeclient routeinternalclientset.Interface, projectclient projectclient.ProjectResourceInterface, kc kclientset.Interface) *controllerfactory.RouterControllerFactory {
 	factory := controllerfactory.NewDefaultRouterControllerFactory(routeclient, kc)
-	factory.Labels = o.Labels
-	factory.Fields = o.Fields
+	factory.LabelSelector = o.LabelSelector
+	factory.FieldSelector = o.FieldSelector
 	factory.Namespace = o.Namespace
 	factory.ResyncInterval = o.ResyncInterval
 	switch {