From 5f52d8462a8790beb6cf20f1bad8a4416b93e1d2 Mon Sep 17 00:00:00 2001
From: wuyingjun <wuyingjun_yewu@cmss.chinamobile.com>
Date: Thu, 14 Dec 2023 17:52:53 +0800
Subject: [PATCH] add informer factory and gvr register

Signed-off-by: wuyingjun <wuyingjun_yewu@cmss.chinamobile.com>
---
 pkg/utils/informers/InformerFactory.go | 130 +++++++++++++++++++++++++
 1 file changed, 130 insertions(+)
 create mode 100644 pkg/utils/informers/InformerFactory.go

diff --git a/pkg/utils/informers/InformerFactory.go b/pkg/utils/informers/InformerFactory.go
new file mode 100644
index 000000000..f06cb63a3
--- /dev/null
+++ b/pkg/utils/informers/InformerFactory.go
@@ -0,0 +1,130 @@
+package informers
+
+import (
+	"time"
+
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes"
+	klog2 "k8s.io/klog/v2"
+
+	kosmosversioned "github.com/kosmos.io/kosmos/pkg/generated/clientset/versioned"
+	kosmosinformers "github.com/kosmos.io/kosmos/pkg/generated/informers/externalversions"
+)
+
+const DefaultResync = 3600 * time.Second
+
+type InformerFactory interface {
+	//K8sInformerFactory return the default InformerFactory
+	K8sInformerFactory() informers.SharedInformerFactory
+
+	//KosmosInformerFactory return the kosmos InformerFactory
+	KosmosInformerFactory() kosmosinformers.SharedInformerFactory
+
+	// SyncCache blocks until all register informers' caches were synced
+	// or the stop channel gets closed.
+	SyncCache(stopCh <-chan struct{}) error
+}
+
+type informerFactory struct {
+	k8sClient    kubernetes.Interface
+	kosmosClient kosmosversioned.Interface
+
+	k8sInformerFactory    informers.SharedInformerFactory
+	kosmosInformerFactory kosmosinformers.SharedInformerFactory
+
+	k8sResources    map[schema.GroupVersion][]string
+	kosmosResources map[schema.GroupVersion][]string
+}
+
+func NewInformerFactory(
+	k8sClient kubernetes.Interface,
+	kosmosClient kosmosversioned.Interface,
+	k8sResources map[schema.GroupVersion][]string,
+	kosmosResources map[schema.GroupVersion][]string) InformerFactory {
+	if k8sClient == nil || kosmosClient == nil {
+		klog2.Fatal("Leaf client is nil, exit os !")
+	}
+	k8sInformerFactory := informers.NewSharedInformerFactory(k8sClient, DefaultResync)
+	kosmosInformerFactory := kosmosinformers.NewSharedInformerFactory(kosmosClient, DefaultResync)
+	return &informerFactory{
+		k8sClient:             k8sClient,
+		kosmosClient:          kosmosClient,
+		k8sInformerFactory:    k8sInformerFactory,
+		kosmosInformerFactory: kosmosInformerFactory,
+		k8sResources:          k8sResources,
+		kosmosResources:       kosmosResources}
+}
+
+func (i *informerFactory) K8sInformerFactory() informers.SharedInformerFactory {
+	return i.k8sInformerFactory
+}
+
+func (i *informerFactory) KosmosInformerFactory() kosmosinformers.SharedInformerFactory {
+	return i.kosmosInformerFactory
+}
+
+// SyncCache blocks until all register informers' caches were synced
+// or the stop channel gets closed.
+func (i *informerFactory) SyncCache(stopCh <-chan struct{}) error {
+	discoveryClient := i.k8sClient.Discovery()
+
+	if i.k8sResources != nil && len(i.k8sResources) != 0 {
+		registerFunc := func(resource schema.GroupVersionResource) (interface{}, error) {
+			return i.k8sInformerFactory.ForResource(resource)
+		}
+		if err := registerCacheInSharedInformerFactory(discoveryClient, registerFunc, i.k8sResources); err != nil {
+			return err
+		}
+	}
+	i.k8sInformerFactory.Start(stopCh)
+	i.k8sInformerFactory.WaitForCacheSync(stopCh)
+
+	if i.kosmosResources != nil && len(i.kosmosResources) != 0 {
+		registerFunc := func(resource schema.GroupVersionResource) (interface{}, error) {
+			return i.kosmosInformerFactory.ForResource(resource)
+		}
+		if err := registerCacheInSharedInformerFactory(discoveryClient, registerFunc, i.kosmosResources); err != nil {
+			return err
+		}
+	}
+
+	i.kosmosInformerFactory.Start(stopCh)
+	i.kosmosInformerFactory.WaitForCacheSync(stopCh)
+
+	return nil
+}
+
+// registerCacheInSharedInformerFactory is for register gvr to informer factory
+func registerCacheInSharedInformerFactory(discoveryClient discovery.DiscoveryInterface, registerFunc func(resource schema.GroupVersionResource) (interface{}, error), gvrs map[schema.GroupVersion][]string) error {
+	for groupVersion, resourceNames := range gvrs {
+		apiResourceList, err := discoveryClient.ServerResourcesForGroupVersion(groupVersion.String())
+		if err != nil {
+			klog2.Errorf("get %s ApiResource List error,", groupVersion.String(), err)
+			return err
+		}
+		for _, resourceName := range resourceNames {
+			if !apiResourceExists(apiResourceList.APIResources, resourceName) {
+				klog2.Errorf("resource %s not exists in the cluster", resourceName)
+			} else {
+				groupVersionResource := groupVersion.WithResource(resourceName)
+				if _, err = registerFunc(groupVersionResource); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// apiResourceExists judge the current gvr is exist
+func apiResourceExists(apiResources []v1.APIResource, resourceName string) bool {
+	for _, apiResource := range apiResources {
+		if apiResource.Name == resourceName {
+			return true
+		}
+	}
+	return false
+}