Refactor Kubernetes Client Factory and Introduce Red Hat Extensions

- Added a new function `NewKubernetesClientFactory` to handle client creation based on authentication method.
- Introduced a new markdown file for documenting BFF handler extensions for downstream builds.
- Implemented handler overrides for Model Registry Settings to support Red Hat-specific behavior.
- Created a new repository for Model Registry Settings with Kubernetes integration.
- Added methods for CRUD operations on Model Registry settings, including handling database secrets.
- Implemented conversion functions for unstructured Kubernetes objects to strongly typed models.
- Ensured that all new functionality adheres to existing interfaces and maintains backward compatibility.

Author: ederign

clients/ui/bff/.vscode/launch.json

@@ -9,7 +9,7 @@
       "program": "${workspaceFolder}/bin/bff",
       "args": [
         "--port=4000",
-        "--auth-method=internal",
+        "--auth-method=user_token",
         "--auth-token-header=Authorization",
         "--auth-token-prefix=Bearer",
         "--static-assets-dir=./static",
@@ -30,7 +30,7 @@
       "program": "${workspaceFolder}/bin/bff",
       "args": [
         "--port=4000",
-        "--auth-method=internal",
+        "--auth-method=user_token",
         "--auth-token-header=Authorization",
         "--auth-token-prefix=Bearer",
         "--static-assets-dir=./static",
@@ -51,13 +51,34 @@
       "program": "${workspaceFolder}/bin/bff",
       "args": [
         "--port=4000",
-        "--auth-method=internal",
+        "--auth-method=user_token",
         "--auth-token-header=Authorization",
         "--auth-token-prefix=Bearer",
         "--static-assets-dir=./static",
         "--mock-k8s-client=false",
         "--mock-mr-client=false",
-        "--dev-mode=false",
+        "--dev-mode=true",
+        "--dev-mode-port=8080",
+        "--standalone-mode=true",
+        "--log-level=info" 
+      ],
+      "preLaunchTask": "make build debug"
+    },
+    {
+      "name": "XFW Debug BFF (MOCK_K8S_CLIENT=false, MOCK_MR_CLIENT=false)",
+      "type": "go",
+      "request": "launch",
+      "mode": "exec",
+      "program": "${workspaceFolder}/bin/bff",
+      "args": [
+        "--port=4000",
+        "--auth-method=user_token_red_hat",
+        "--auth-token-header=X-Forwarded-Access-Token",
+        "--auth-token-prefix=",
+        "--static-assets-dir=./static",
+        "--mock-k8s-client=false",
+        "--mock-mr-client=false",
+        "--dev-mode=true",
         "--dev-mode-port=8080",
         "--standalone-mode=true",
         "--log-level=info" 

clients/ui/bff/cmd/main.go

@@ -11,6 +11,9 @@ import (
 	"github.com/kubeflow/model-registry/ui/bff/internal/api"
 	"github.com/kubeflow/model-registry/ui/bff/internal/config"
 
+	// Import redhat handlers to register handler overrides via init()
+	_ "github.com/kubeflow/model-registry/ui/bff/internal/redhat/handlers"
+
 	"log/slog"
 	"net/http"
 	"os"

clients/ui/bff/internal/api/app.go

@@ -75,6 +75,15 @@ const (
 	CatalogSourcePreviewPath                 = ModelCatalogSettingsPathPrefix + "/source_preview"
 )
 
+const (
+	// TODO(upstream): Keep handler IDs unexported so the extension mechanism stays agnostic of downstream overrides.
+	handlerModelRegistrySettingsListID   HandlerID = "modelRegistrySettings:list"
+	handlerModelRegistrySettingsCreateID HandlerID = "modelRegistrySettings:create"
+	handlerModelRegistrySettingsGetID    HandlerID = "modelRegistrySettings:get"
+	handlerModelRegistrySettingsUpdateID HandlerID = "modelRegistrySettings:update"
+	handlerModelRegistrySettingsDeleteID HandlerID = "modelRegistrySettings:delete"
+)
+
 type App struct {
 	config                  config.EnvConfig
 	logger                  *slog.Logger
@@ -251,11 +260,36 @@ func (app *App) Routes() http.Handler {
 		// SettingsPath endpoints are used to manage the model registry settings and create new model registries
 		// We are still discussing the best way to create model registries in the community
 		// But in the meantime, those endpoints are STUBs endpoints used to unblock the frontend development
-		apiRouter.GET(ModelRegistrySettingsListPath, app.AttachNamespace(app.GetAllModelRegistriesSettingsHandler))
-		apiRouter.POST(ModelRegistrySettingsListPath, app.AttachNamespace(app.CreateModelRegistrySettingsHandler))
-		apiRouter.GET(ModelRegistrySettingsPath, app.AttachNamespace(app.GetModelRegistrySettingsHandler))
-		apiRouter.PATCH(ModelRegistrySettingsPath, app.AttachNamespace(app.UpdateModelRegistrySettingsHandler))
-		apiRouter.DELETE(ModelRegistrySettingsPath, app.AttachNamespace(app.DeleteModelRegistrySettingsHandler))
+		apiRouter.GET(
+			ModelRegistrySettingsListPath,
+			app.handlerWithOverride(handlerModelRegistrySettingsListID, func() httprouter.Handle {
+				return app.AttachNamespace(app.GetAllModelRegistriesSettingsHandler)
+			}),
+		)
+		apiRouter.POST(
+			ModelRegistrySettingsListPath,
+			app.handlerWithOverride(handlerModelRegistrySettingsCreateID, func() httprouter.Handle {
+				return app.AttachNamespace(app.CreateModelRegistrySettingsHandler)
+			}),
+		)
+		apiRouter.GET(
+			ModelRegistrySettingsPath,
+			app.handlerWithOverride(handlerModelRegistrySettingsGetID, func() httprouter.Handle {
+				return app.AttachNamespace(app.GetModelRegistrySettingsHandler)
+			}),
+		)
+		apiRouter.PATCH(
+			ModelRegistrySettingsPath,
+			app.handlerWithOverride(handlerModelRegistrySettingsUpdateID, func() httprouter.Handle {
+				return app.AttachNamespace(app.UpdateModelRegistrySettingsHandler)
+			}),
+		)
+		apiRouter.DELETE(
+			ModelRegistrySettingsPath,
+			app.handlerWithOverride(handlerModelRegistrySettingsDeleteID, func() httprouter.Handle {
+				return app.AttachNamespace(app.DeleteModelRegistrySettingsHandler)
+			}),
+		)
 
 		//SettingsPath: Certificate endpoints
 		apiRouter.GET(CertificatesPath, app.AttachNamespace(app.GetCertificatesHandler))

clients/ui/bff/internal/api/extensions.go

@@ -0,0 +1,54 @@
+package api
+
+import (
+	"log/slog"
+	"sync"
+
+	"github.com/julienschmidt/httprouter"
+)
+
+// HandlerID identifies an overridable HTTP handler.
+// TODO(upstream): Keep this type exported so downstream code can reference arbitrary handler keys without
+// requiring upstream to enumerate them.
+type HandlerID string
+
+// HandlerFactory builds a router handler that has access to the App instance.
+// Implementations can opt to call buildDefault() to reuse the default upstream handler.
+type HandlerFactory func(app *App, buildDefault func() httprouter.Handle) httprouter.Handle
+
+var (
+	handlerOverrideMu sync.RWMutex
+	handlerOverrides  = map[HandlerID]HandlerFactory{}
+)
+
+// RegisterHandlerOverride allows downstream code to override a specific handler.
+// TODO(downstream): Call this from vendor packages (e.g., internal/redhat/handlers) to inject custom behavior.
+// Calling this function multiple times for the same id will replace the previous override.
+func RegisterHandlerOverride(id HandlerID, factory HandlerFactory) {
+	handlerOverrideMu.Lock()
+	defer handlerOverrideMu.Unlock()
+	handlerOverrides[id] = factory
+}
+
+func getHandlerOverride(id HandlerID) HandlerFactory {
+	handlerOverrideMu.RLock()
+	defer handlerOverrideMu.RUnlock()
+	return handlerOverrides[id]
+}
+
+// handlerWithOverride returns the handler registered for the given id or builds the default one.
+// TODO(upstream): This glue stays upstream so the router keeps working even when no downstream overrides exist.
+func (app *App) handlerWithOverride(id HandlerID, buildDefault func() httprouter.Handle) httprouter.Handle {
+	if factory := getHandlerOverride(id); factory != nil {
+		app.logHandlerOverride(id)
+		return factory(app, buildDefault)
+	}
+	return buildDefault()
+}
+
+func (app *App) logHandlerOverride(id HandlerID) {
+	if app == nil || app.logger == nil {
+		return
+	}
+	app.logger.Debug("Using handler override", slog.String("handlerID", string(id)))
+}

clients/ui/bff/internal/api/model_registry_settings_handler.go

@@ -18,8 +18,6 @@ type ModelRegistryAndCredentialsSettingsEnvelope Envelope[models.ModelRegistryAn
 type ModelRegistrySettingsPayloadEnvelope Envelope[models.ModelRegistrySettingsPayload, None]
 
 func (app *App) GetAllModelRegistriesSettingsHandler(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
-	ctxLogger := helper.GetContextLoggerFromReq(r)
-	ctxLogger.Info("This functionality is not implement yet. This is a STUB API to unblock frontend development")
 
 	namespace, ok := r.Context().Value(constants.NamespaceHeaderParameterKey).(string)
 	if !ok || namespace == "" {
@@ -36,17 +34,17 @@ func (app *App) GetAllModelRegistriesSettingsHandler(w http.ResponseWriter, r *h
 		Key:  "ssl-secret-key",
 	}
 
-	registries := []models.ModelRegistryKind{createSampleModelRegistry("model-registry", namespace, &sslRootCertificateConfigMap, nil),
+	registries := []models.ModelRegistryKind{
+		createSampleModelRegistry("model-registry", namespace, &sslRootCertificateConfigMap, nil),
 		createSampleModelRegistry("model-registry-dora", namespace, nil, &sslRootCertificateSecret),
-		createSampleModelRegistry("model-registry-bella", namespace, nil, nil)}
+		createSampleModelRegistry("model-registry-bella", namespace, nil, nil),
+	}
 
 	modelRegistryRes := ModelRegistrySettingsListEnvelope{
 		Data: registries,
 	}
 
-	err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil)
-
-	if err != nil {
+	if err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil); err != nil {
 		app.serverErrorResponse(w, r, err)
 	}
 
@@ -73,9 +71,7 @@ func (app *App) GetModelRegistrySettingsHandler(w http.ResponseWriter, r *http.R
 		Data: modelRegistryWithCreds,
 	}
 
-	err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil)
-
-	if err != nil {
+	if err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil); err != nil {
 		app.serverErrorResponse(w, r, err)
 	}
 }
@@ -94,31 +90,18 @@ func (app *App) CreateModelRegistrySettingsHandler(w http.ResponseWriter, r *htt
 		app.serverErrorResponse(w, r, fmt.Errorf("error decoding JSON:: %v", err.Error()))
 		return
 	}
-
-	var modelRegistryName = envelope.Data.ModelRegistry.Metadata.Name
-
-	if modelRegistryName == "" {
-		app.badRequestResponse(w, r, fmt.Errorf("model registry name is required"))
-		return
-	}
-
-	ctxLogger.Info("Creating model registry", "name", modelRegistryName)
-
-	// For now, we're using the stub implementation, but we'd use envelope.Data.ModelRegistry
-	// and other fields from the payload in a real implementation
+	modelRegistryName := envelope.Data.ModelRegistry.Metadata.Name
 	registry := createSampleModelRegistry(modelRegistryName, namespace, nil, nil)
 
 	modelRegistryRes := ModelRegistrySettingsEnvelope{
 		Data: registry,
 	}
 
 	w.Header().Set("Location", r.URL.JoinPath(modelRegistryRes.Data.Metadata.Name).String())
-	writeErr := app.WriteJSON(w, http.StatusCreated, modelRegistryRes, nil)
-	if writeErr != nil {
+	if err := app.WriteJSON(w, http.StatusCreated, modelRegistryRes, nil); err != nil {
 		app.serverErrorResponse(w, r, fmt.Errorf("error writing JSON"))
 		return
 	}
-
 }
 
 func (app *App) UpdateModelRegistrySettingsHandler(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
@@ -137,8 +120,7 @@ func (app *App) UpdateModelRegistrySettingsHandler(w http.ResponseWriter, r *htt
 		Data: registry,
 	}
 
-	err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil)
-	if err != nil {
+	if err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil); err != nil {
 		app.serverErrorResponse(w, r, fmt.Errorf("error writing JSON"))
 		return
 	}
@@ -161,9 +143,7 @@ func (app *App) DeleteModelRegistrySettingsHandler(w http.ResponseWriter, r *htt
 		Data: registry,
 	}
 
-	err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil)
-
-	if err != nil {
+	if err := app.WriteJSON(w, http.StatusOK, modelRegistryRes, nil); err != nil {
 		app.serverErrorResponse(w, r, err)
 	}
 

clients/ui/bff/internal/api/public_helpers.go

@@ -0,0 +1,53 @@
+package api
+
+import (
+	"fmt"
+	"net/http"
+
+	"log/slog"
+
+	"github.com/kubeflow/model-registry/ui/bff/internal/config"
+	k8s "github.com/kubeflow/model-registry/ui/bff/internal/integrations/kubernetes"
+	"github.com/kubeflow/model-registry/ui/bff/internal/repositories"
+)
+
+// BadRequest exposes the internal bad request helper for extensions.
+func (app *App) BadRequest(w http.ResponseWriter, r *http.Request, err error) {
+	if app == nil {
+		return
+	}
+	app.badRequestResponse(w, r, err)
+}
+
+// ServerError exposes the internal server error helper for extensions.
+func (app *App) ServerError(w http.ResponseWriter, r *http.Request, err error) {
+	if app == nil {
+		return
+	}
+	app.serverErrorResponse(w, r, err)
+}
+
+// NotImplemented writes a standard placeholder response for unimplemented endpoints.
+func (app *App) NotImplemented(w http.ResponseWriter, r *http.Request, feature string) {
+	app.serverErrorResponse(w, r, fmt.Errorf("%s is not implemented", feature))
+}
+
+// Config exposes the application configuration for extensions.
+func (app *App) Config() config.EnvConfig {
+	return app.config
+}
+
+// Logger exposes the application logger for extensions.
+func (app *App) Logger() *slog.Logger {
+	return app.logger
+}
+
+// KubernetesClientFactory exposes the k8s factory for extensions.
+func (app *App) KubernetesClientFactory() k8s.KubernetesClientFactory {
+	return app.kubernetesClientFactory
+}
+
+// Repositories exposes the repositories container for extensions.
+func (app *App) Repositories() *repositories.Repositories {
+	return app.repositories
+}

clients/ui/bff/internal/api/test_app.go

@@ -0,0 +1,25 @@
+package api
+
+import (
+	"io"
+	"log/slog"
+
+	"github.com/kubeflow/model-registry/ui/bff/internal/config"
+	k8s "github.com/kubeflow/model-registry/ui/bff/internal/integrations/kubernetes"
+	"github.com/kubeflow/model-registry/ui/bff/internal/repositories"
+)
+
+// NewTestApp exposes a minimal constructor that allows tests and downstream
+// extensions to configure specific App dependencies without invoking the
+// production bootstrap logic.
+func NewTestApp(cfg config.EnvConfig, logger *slog.Logger, factory k8s.KubernetesClientFactory, repos *repositories.Repositories) *App {
+	if logger == nil {
+		logger = slog.New(slog.NewTextHandler(io.Discard, nil))
+	}
+	return &App{
+		config:                  cfg,
+		logger:                  logger,
+		kubernetesClientFactory: factory,
+		repositories:            repos,
+	}
+}

clients/ui/bff/internal/integrations/kubernetes/client.go

@@ -2,6 +2,7 @@ package kubernetes
 
 import (
 	"context"
+
 	corev1 "k8s.io/api/core/v1"
 )