From da4a4e2e1628975935e43cc0f8977ccbdd01016c Mon Sep 17 00:00:00 2001
From: Eric Lin <exlin@google.com>
Date: Sun, 4 Jun 2023 12:26:58 +0000
Subject: [PATCH] Add 'WithTransform' SharedInformerOption

Also add support for metadata informer factory to use SharedInformerOption

Signed-off-by: Eric Lin <exlin@google.com>

Kubernetes-commit: 9c4651bd0479b84f5e5913649207476717f3f13e
---
 metadata/metadatainformer/informer.go | 32 +++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/metadata/metadatainformer/informer.go b/metadata/metadatainformer/informer.go
index c211a4b7..ff3537e9 100644
--- a/metadata/metadatainformer/informer.go
+++ b/metadata/metadatainformer/informer.go
@@ -21,6 +21,7 @@ import (
 	"sync"
 	"time"
 
+	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
@@ -31,6 +32,17 @@ import (
 	"k8s.io/client-go/tools/cache"
 )
 
+// SharedInformerOption defines the functional option type for metadataSharedInformerFactory.
+type SharedInformerOption func(*metadataSharedInformerFactory) *metadataSharedInformerFactory
+
+// WithTransform sets a transform on all informers.
+func WithTransform(transform cache.TransformFunc) SharedInformerOption {
+	return func(factory *metadataSharedInformerFactory) *metadataSharedInformerFactory {
+		factory.transform = transform
+		return factory
+	}
+}
+
 // NewSharedInformerFactory constructs a new instance of metadataSharedInformerFactory for all namespaces.
 func NewSharedInformerFactory(client metadata.Interface, defaultResync time.Duration) SharedInformerFactory {
 	return NewFilteredSharedInformerFactory(client, defaultResync, metav1.NamespaceAll, nil)
@@ -49,10 +61,29 @@ func NewFilteredSharedInformerFactory(client metadata.Interface, defaultResync t
 	}
 }
 
+// NewSharedInformerFactoryWithOptions constructs a new instance of metadataSharedInformerFactory with additional options.
+func NewSharedInformerFactoryWithOptions(client metadata.Interface, defaultResync time.Duration, options ...SharedInformerOption) SharedInformerFactory {
+	factory := &metadataSharedInformerFactory{
+		client:           client,
+		namespace:        v1.NamespaceAll,
+		defaultResync:    defaultResync,
+		informers:        map[schema.GroupVersionResource]informers.GenericInformer{},
+		startedInformers: make(map[schema.GroupVersionResource]bool),
+	}
+
+	// Apply all options
+	for _, opt := range options {
+		factory = opt(factory)
+	}
+
+	return factory
+}
+
 type metadataSharedInformerFactory struct {
 	client        metadata.Interface
 	defaultResync time.Duration
 	namespace     string
+	transform     cache.TransformFunc
 
 	lock      sync.Mutex
 	informers map[schema.GroupVersionResource]informers.GenericInformer
@@ -80,6 +111,7 @@ func (f *metadataSharedInformerFactory) ForResource(gvr schema.GroupVersionResou
 	}
 
 	informer = NewFilteredMetadataInformer(f.client, gvr, f.namespace, f.defaultResync, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc}, f.tweakListOptions)
+	informer.Informer().SetTransform(f.transform)
 	f.informers[key] = informer
 
 	return informer