Add enable function and addFeature functions

Added enable function to schemas. This allows filtering of schemas
which is a required part of feature flagging in rancher. Added
addFeature functions to controller template for adding handlers that
can be disabled if their associated feature is disabled.

generator/controller_template.go

@@ -74,7 +74,9 @@ type {{.schema.CodeName}}Controller interface {
 	Informer() cache.SharedIndexInformer
 	Lister() {{.schema.CodeName}}Lister
 	AddHandler(ctx context.Context, name string, handler {{.schema.CodeName}}HandlerFunc)
+	AddFeatureHandler(ctx context.Context, enabled func() bool, name string, sync {{.schema.CodeName}}HandlerFunc)
 	AddClusterScopedHandler(ctx context.Context, name, clusterName string, handler {{.schema.CodeName}}HandlerFunc)
+	AddClusterScopedFeatureHandler(ctx context.Context, enabled func() bool, name, clusterName string, handler {{.schema.CodeName}}HandlerFunc)
 	Enqueue(namespace, name string)
 	Sync(ctx context.Context) error
 	Start(ctx context.Context, threadiness int) error
@@ -93,9 +95,13 @@ type {{.schema.CodeName}}Interface interface {
 	DeleteCollection(deleteOpts *metav1.DeleteOptions, listOpts metav1.ListOptions) error
 	Controller() {{.schema.CodeName}}Controller
 	AddHandler(ctx context.Context, name string, sync {{.schema.CodeName}}HandlerFunc)
+	AddFeatureHandler(ctx context.Context, enabled func() bool, name string, sync {{.schema.CodeName}}HandlerFunc)
 	AddLifecycle(ctx context.Context, name string, lifecycle {{.schema.CodeName}}Lifecycle)
+	AddFeatureLifecycle(ctx context.Context, enabled func() bool, name string, lifecycle {{.schema.CodeName}}Lifecycle)
 	AddClusterScopedHandler(ctx context.Context, name, clusterName string, sync {{.schema.CodeName}}HandlerFunc)
+	AddClusterScopedFeatureHandler(ctx context.Context, enabled func() bool, name, clusterName string, sync {{.schema.CodeName}}HandlerFunc)
 	AddClusterScopedLifecycle(ctx context.Context, name, clusterName string, lifecycle {{.schema.CodeName}}Lifecycle)
+	AddClusterScopedFeatureLifecycle(ctx context.Context, enabled func() bool, name, clusterName string, lifecycle {{.schema.CodeName}}Lifecycle)
 }
 
 type {{.schema.ID}}Lister struct {
@@ -156,6 +162,20 @@ func (c *{{.schema.ID}}Controller) AddHandler(ctx context.Context, name string,
 	})
 }
 
+func (c *{{.schema.ID}}Controller) AddFeatureHandler(ctx context.Context, enabled func() bool, name string, handler {{.schema.CodeName}}HandlerFunc) {
+	c.GenericController.AddHandler(ctx, name, func(key string, obj interface{}) (interface{}, error) {
+		if !enabled() {
+			return nil, nil
+		} else if obj == nil {
+			return handler(key, nil)
+		} else if v, ok := obj.(*{{.prefix}}{{.schema.CodeName}}); ok {
+			return handler(key, v)
+		} else {
+			return nil, nil
+		}
+	})
+}
+
 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) {
@@ -169,6 +189,21 @@ func (c *{{.schema.ID}}Controller) AddClusterScopedHandler(ctx context.Context,
 	})
 }
 
+func (c *{{.schema.ID}}Controller) AddClusterScopedFeatureHandler(ctx context.Context, enabled func() bool, 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 !enabled() {
+			return nil, nil
+		} else if obj == nil {
+			return handler(key, nil)
+		} else if v, ok := obj.(*{{.prefix}}{{.schema.CodeName}}); ok && controller.ObjectInCluster(cluster, obj) {
+			return handler(key, v)
+		} else {
+			return nil, nil
+		}
+	})
+}
+
 type {{.schema.ID}}Factory struct {
 }
 
@@ -264,20 +299,38 @@ func (s *{{.schema.ID}}Client) AddHandler(ctx context.Context, name string, sync
 	s.Controller().AddHandler(ctx, name, sync)
 }
 
+func (s *{{.schema.ID}}Client) AddFeatureHandler(ctx context.Context, enabled func() bool, name string, sync {{.schema.CodeName}}HandlerFunc) {
+	s.Controller().AddFeatureHandler(ctx, enabled, name, sync)
+}
+
 func (s *{{.schema.ID}}Client) AddLifecycle(ctx context.Context, name string, lifecycle {{.schema.CodeName}}Lifecycle) {
 	sync := New{{.schema.CodeName}}LifecycleAdapter(name, false, s, lifecycle)
 	s.Controller().AddHandler(ctx, name, sync)
 }
 
+func (s *{{.schema.ID}}Client) AddFeatureLifecycle(ctx context.Context, enabled func() bool, name string, lifecycle {{.schema.CodeName}}Lifecycle) {
+	sync := New{{.schema.CodeName}}LifecycleAdapter(name, false, s, lifecycle)
+	s.Controller().AddFeatureHandler(ctx, enabled, name, sync)
+}
+
 func (s *{{.schema.ID}}Client) AddClusterScopedHandler(ctx context.Context, name, clusterName string, sync {{.schema.CodeName}}HandlerFunc) {
 	s.Controller().AddClusterScopedHandler(ctx, name, clusterName, sync)
 }
 
+func (s *{{.schema.ID}}Client) AddClusterScopedFeatureHandler(ctx context.Context, enabled func() bool, name, clusterName string, sync {{.schema.CodeName}}HandlerFunc) {
+	s.Controller().AddClusterScopedFeatureHandler(ctx, enabled, name, clusterName, sync)
+}
+
 func (s *{{.schema.ID}}Client) AddClusterScopedLifecycle(ctx context.Context, name, clusterName string, lifecycle {{.schema.CodeName}}Lifecycle) {
 	sync := New{{.schema.CodeName}}LifecycleAdapter(name+"_"+clusterName, true, s, lifecycle)
 	s.Controller().AddClusterScopedHandler(ctx, name, clusterName, sync)
 }
 
+func (s *{{.schema.ID}}Client) AddClusterScopedFeatureLifecycle(ctx context.Context, enabled func() bool, name, clusterName string, lifecycle {{.schema.CodeName}}Lifecycle) {
+	sync := New{{.schema.CodeName}}LifecycleAdapter(name+"_"+clusterName, true, s, lifecycle)
+	s.Controller().AddClusterScopedFeatureHandler(ctx, enabled, name, clusterName, sync)
+}
+
 type {{.schema.CodeName}}Indexer func(obj *{{.prefix}}{{.schema.CodeName}}) ([]string, error)
 
 type {{.schema.CodeName}}ClientCache interface {

parse/parse.go

@@ -130,6 +130,12 @@ func Parse(rw http.ResponseWriter, req *http.Request, schemas *types.Schemas, ur
 		return result, err
 	}
 
+	if schema := result.Schema; schema.Enabled != nil {
+		if !schema.Enabled() {
+			return result, httperror.NewAPIError(httperror.ActionNotAvailable, "schema disabled "+schema.ID)
+		}
+	}
+
 	result.Type = result.Schema.ID
 
 	if err := ValidateMethod(result); err != nil {

store/schema/schema_store.go

@@ -23,6 +23,12 @@ func NewSchemaStore() types.Store {
 func (s *Store) ByID(apiContext *types.APIContext, schema *types.Schema, id string) (map[string]interface{}, error) {
 	for _, schema := range apiContext.Schemas.SchemasForVersion(*apiContext.Version) {
 		if strings.EqualFold(schema.ID, id) {
+			if schema.Enabled != nil {
+				if !schema.Enabled() {
+					return nil, httperror.NewAPIError(httperror.NotFound, "schema disabled")
+				}
+			}
+
 			schemaData := map[string]interface{}{}
 
 			data, err := json.Marshal(s.modifyForAccessControl(apiContext, *schema))
@@ -78,6 +84,12 @@ func (s *Store) List(apiContext *types.APIContext, schema *types.Schema, opt *ty
 			continue
 		}
 
+		if schema.Enabled != nil {
+			if !schema.Enabled() {
+				continue
+			}
+		}
+
 		if schema.CanList(apiContext) == nil || schema.CanGet(apiContext) == nil {
 			schemas = s.addSchema(apiContext, schema, schemaMap, schemas, included)
 		}

types/types.go

@@ -114,6 +114,7 @@ type Schema struct {
 	CollectionFilters    map[string]Filter `json:"collectionFilters,omitempty"`
 	DynamicSchemaVersion string            `json:"dynamicSchemaVersion,omitempty"`
 	Scope                TypeScope         `json:"-"`
+	Enabled              func() bool       `json:"-"`
 
 	InternalSchema      *Schema             `json:"-"`
 	Mapper              Mapper              `json:"-"`