Perf improvements for existing resource restore

Use informer cache with dynamic client for Get calls on restore
When enabled, also make the Get call before create.

Add server and install parameter to allow disabling this feature,
but enable by default

Signed-off-by: Scott Seago <sseago@redhat.com>

pkg/client/dynamic.go

@@ -18,6 +18,7 @@ package client
 
 import (
 	"context"
+	"time"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -25,6 +26,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/client-go/dynamic"
+	"k8s.io/client-go/dynamic/dynamicinformer"
 )
 
 // DynamicFactory contains methods for retrieving dynamic clients for GroupVersionResources and
@@ -33,6 +35,8 @@ type DynamicFactory interface {
 	// ClientForGroupVersionResource returns a Dynamic client for the given group/version
 	// and resource for the given namespace.
 	ClientForGroupVersionResource(gv schema.GroupVersion, resource metav1.APIResource, namespace string) (Dynamic, error)
+	// DynamicSharedInformerFactoryForNamespace returns a DynamicSharedInformerFactory for the given namespace.
+	DynamicSharedInformerFactoryForNamespace(namespace string) dynamicinformer.DynamicSharedInformerFactory
 }
 
 // dynamicFactory implements DynamicFactory.
@@ -51,6 +55,10 @@ func (f *dynamicFactory) ClientForGroupVersionResource(gv schema.GroupVersion, r
 	}, nil
 }
 
+func (f *dynamicFactory) DynamicSharedInformerFactoryForNamespace(namespace string) dynamicinformer.DynamicSharedInformerFactory {
+	return dynamicinformer.NewFilteredDynamicSharedInformerFactory(f.dynamicClient, time.Minute, namespace, nil)
+}
+
 // Creator creates an object.
 type Creator interface {
 	// Create creates an object.