Refactor set of cluster scoped handlers

Problem: Cluster scoped gc was taking significantly longer to complete
than before 7387aa5. This was due to a large number of list calls and
the time needed to iterate over them.

Solution: Instead of requesting every type than Rancher uses, a
seperate map appended to when a cluster scoped handler
is created. The full map of all GroupVersionResources is kept as a
fallback for the use case where user controllers may exist on another
host other than the current leader.

generator/controller_template.go

@@ -157,6 +157,7 @@ func (c *{{.schema.ID}}Controller) AddHandler(ctx context.Context, name string,
 }
 
 func (c *{{.schema.ID}}Controller) AddClusterScopedHandler(ctx context.Context, name, cluster string, handler {{.schema.CodeName}}HandlerFunc) {
+	resource.PutClusterScoped({{.schema.CodeName}}GroupVersionResource)
 	c.GenericController.AddHandler(ctx, name, func(key string, obj interface{}) (interface{}, error) {
 		if obj == nil {
 			return handler(key, nil)

resource/resource.go

@@ -7,11 +7,17 @@ import (
 )
 
 //rancherTypes is a set of all types generated by rancher
+//clusterScopedTypes is a set of all types that have been added by a clusterScoped handler
 var (
 	rancherTypes = struct {
 		sync.RWMutex
 		m map[schema.GroupVersionResource]bool
 	}{m: make(map[schema.GroupVersionResource]bool)}
+
+	clusterScopedTypes = struct {
+		sync.RWMutex
+		m map[schema.GroupVersionResource]bool
+	}{m: make(map[schema.GroupVersionResource]bool)}
 )
 
 //Get returns a copy of the set of rancherTypes
@@ -25,6 +31,16 @@ func Get() map[schema.GroupVersionResource]bool {
 	return targetMap
 }
 
+func GetClusterScopedTypes() map[schema.GroupVersionResource]bool {
+	clusterScopedTypes.Lock()
+	defer clusterScopedTypes.Unlock()
+	targetMap := make(map[schema.GroupVersionResource]bool, len(clusterScopedTypes.m))
+	for key, value := range clusterScopedTypes.m {
+		targetMap[key] = value
+	}
+	return targetMap
+}
+
 //Put adds an object to the set and panic on collision
 func Put(key schema.GroupVersionResource) {
 	rancherTypes.Lock()
@@ -36,3 +52,10 @@ func Put(key schema.GroupVersionResource) {
 	}
 	rancherTypes.m[key] = true
 }
+
+//PutClusterScoped adds a object that contains a cluster scoped handler to the set
+func PutClusterScoped(key schema.GroupVersionResource) {
+	clusterScopedTypes.Lock()
+	defer clusterScopedTypes.Unlock()
+	clusterScopedTypes.m[key] = true
+}