Support registration of multiple Porch repositories pointing to the same Git repository, and add webhook validation to detect and handle conflicts during repository creation (kptdev#335)

* Add support for multiple porch repos to connect to the same git repo

- Create validation webhook for repositories.config.porch.kpt.dev
- Update directory naming convention for git repo caching

* Add ns separation for same repos regitered in different namespaces

* Add repolocks for open and close

* Add missing package path and remove duplication of packages when listing

* Add git branch logic for conflicts and use apiserver client in webhooks

* Add cachedir pooling and refactor git.go

* Add Client.Reader for webhooks and modify logs in webhooks.go

* Update Lock, e2e test and reject branch changes

* Create commitopsbuilder and add unit tests

* Use sync.Map to simplify mutex handling and remove client.Reader

* Rebase and refactor e2e tests with new structure

Author: kushnaidu

pkg/apiserver/apiserver.go

@@ -139,7 +139,7 @@ func (c completedConfig) getRestConfig() (*rest.Config, error) {
 	}
 }
 
-func (c completedConfig) getCoreClient() (client.WithWatch, error) {
+func (c completedConfig) buildClient() (client.WithWatch, error) {
 	restConfig, err := c.getRestConfig()
 	if err != nil {
 		return nil, err
@@ -153,26 +153,17 @@ func (c completedConfig) getCoreClient() (client.WithWatch, error) {
 	if err := configapi.AddToScheme(scheme); err != nil {
 		return nil, fmt.Errorf("error building scheme: %w", err)
 	}
-
 	if err := porchapi.AddToScheme(scheme); err != nil {
 		return nil, fmt.Errorf("error building scheme: %w", err)
 	}
-
 	if err := corev1.AddToScheme(scheme); err != nil {
 		return nil, fmt.Errorf("error building scheme: %w", err)
 	}
 	if err := internalapi.AddToScheme(scheme); err != nil {
 		return nil, fmt.Errorf("error building scheme: %w", err)
 	}
 
-	coreClient, err := client.NewWithWatch(restConfig, client.Options{
-		Scheme: scheme,
-	})
-	if err != nil {
-		return nil, fmt.Errorf("error building client for core apiserver: %w", err)
-	}
-
-	return coreClient, nil
+	return client.NewWithWatch(restConfig, client.Options{Scheme: scheme})
 }
 
 func (c completedConfig) getCoreV1Client() (*corev1client.CoreV1Client, error) {
@@ -198,7 +189,7 @@ func (c completedConfig) New(ctx context.Context) (*PorchServer, error) {
 		return nil, err
 	}
 
-	coreClient, err := c.getCoreClient()
+	coreClient, err := c.buildClient()
 	if err != nil {
 		return nil, fmt.Errorf("failed to build client for core apiserver: %w", err)
 	}
@@ -305,7 +296,7 @@ func (s *PorchServer) Run(ctx context.Context) error {
 	// but for now we keep backward compatiblity
 	certStorageDir, found := os.LookupEnv("CERT_STORAGE_DIR")
 	if found && strings.TrimSpace(certStorageDir) != "" {
-		if err := setupWebhooks(ctx); err != nil {
+		if err := setupWebhooks(ctx, s.coreClient); err != nil {
 			klog.Errorf("%v\n", err)
 			return err
 		}