#feat:Native Sidecar Default Mode + Backward Compatibility

pkg/application/inject/fuse/injector.go

@@ -24,6 +24,7 @@ import (
 	"github.com/fluid-cloudnative/fluid/pkg/common"
 	"github.com/fluid-cloudnative/fluid/pkg/ddc/base"
 	"github.com/fluid-cloudnative/fluid/pkg/utils"
+	"github.com/fluid-cloudnative/fluid/pkg/utils/discovery"
 
 	"github.com/fluid-cloudnative/fluid/pkg/utils/applications/defaultapp"
 	podapp "github.com/fluid-cloudnative/fluid/pkg/utils/applications/pod"
@@ -44,10 +45,24 @@ type Injector struct {
 }
 
 func NewInjector(client client.Client) *Injector {
+	configured := common.GetSidecarInjectionMode()
+
+	if configured == common.SidecarInjectionMode_Default {
+		cfg, err := ctrl.GetConfig()
+		if err != nil {
+			// Fall back to legacy if we can't get config
+			ctrl.Log.WithName("fuse-injector").Error(err, "Failed to get k8s config, falling back to legacy sidecar mode")
+			configured = common.SidecarInjectionMode_Legacy
+		} else if discovery.SupportsNativeSidecar(cfg) {
+			configured = common.SidecarInjectionMode_NativeSidecar
+		} else {
+			configured = common.SidecarInjectionMode_Legacy
+		}
+	}
 	return &Injector{
 		client:               client,
 		log:                  ctrl.Log.WithName("fuse-injector"),
-		sidecarInjectionMode: common.GetSidecarInjectionMode(),
+		sidecarInjectionMode: configured,
 	}
 }
 

pkg/common/types.go

@@ -189,6 +189,9 @@ func GetSidecarInjectionMode() SidecarInjectionMode {
 		return SidecarInjectionMode_Legacy
 	case "native-sidecar":
 		return SidecarInjectionMode_NativeSidecar
+	case "":
+		// Backward compatibility: old behavior
+		return SidecarInjectionMode_Default
 	default:
 		return SidecarInjectionMode_Default
 	}

pkg/utils/discovery/api_discover.go

@@ -60,11 +60,22 @@ func initDiscovery() {
 }
 
 func discoverFluidResourcesInCluster() {
-	restConfig := ctrl.GetConfigOrDie()
-	var discoveryClient discovery.DiscoveryInterface = discovery.NewDiscoveryClientForConfigOrDie(restConfig)
+	restConfig,err := ctrl.GetConfig()
+	if err!=nil{
+		nativeLog.Fatalf("failed to get kubernetes config: %v", err)
+	}
+
+	if restConfig == nil {
+		nativeLog.Fatalf("kubernetes config is nil")
+	}
+
+	discoveryClient, err := discovery.NewDiscoveryClientForConfig(restConfig)
+	if err != nil {
+		nativeLog.Fatalf("failed to create discovery client: %v", err)
+	}
 	fluidGroupVersion := fmt.Sprintf("%s/%s", datav1alpha1.Group, datav1alpha1.Version)
 
-	err := retry.OnError(backOff, func(err error) bool { return true }, func() error {
+	err = retry.OnError(backOff, func(err error) bool { return true }, func() error {
 		resources, discoverErr := discoveryClient.ServerResourcesForGroupVersion(fluidGroupVersion)
 		if discoverErr != nil {
 			return discoverErr

pkg/utils/discovery/sidecar.go

@@ -0,0 +1,56 @@
+package discovery
+
+import (
+	"log"
+	"strconv"
+	"strings"
+
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/rest"
+)
+
+func SupportsNativeSidecarOrDefault(cfg *rest.Config, defaultValue bool) bool {
+	if cfg == nil {
+		return defaultValue
+	}
+	return SupportsNativeSidecar(cfg)
+}
+
+func SupportsNativeSidecar(cfg *rest.Config) bool {
+	// Add nil check
+	if cfg == nil {
+		return false
+	}
+
+	// fmt.Printf("SupportsNativeSidecar: cfg.Host = %q\n", cfg.Host)
+	dc, err := discovery.NewDiscoveryClientForConfig(cfg)
+	if err != nil {
+		log.Printf("Failed to create discovery client for native sidecar detection: %v", err)
+		return false
+	}
+
+	info, err := dc.ServerVersion()
+	if err != nil {
+		return false
+	}
+
+	majorStr := strings.TrimPrefix(info.Major, "v")
+	minorStr := strings.TrimSuffix(info.Minor, "+")
+
+	major, err := strconv.Atoi(majorStr)
+	if err != nil {
+		return false
+	}
+
+	minor, err := strconv.Atoi(minorStr)
+	if err != nil {
+		return false
+	}
+
+	// native sidecar supported from k8s 1.29+
+	if major > 1 {
+		return true
+	}
+
+	return major == 1 && minor >= 29
+}