feat: add outOfTree plugin entry when initializing scheduler

cmd/scheduler/app/options/options.go

@@ -24,7 +24,7 @@ var (
 	defaultElectionRetryPeriod   = metav1.Duration{Duration: 2 * time.Second}
 )
 
-// Options contains everything necessary to create and run controller-manager.
+// Options contains everything necessary to create and run scheduler.
 type Options struct {
 	LeaderElection componentbaseconfig.LeaderElectionConfiguration
 	KubeConfig     string

cmd/scheduler/app/scheduler.go

@@ -24,14 +24,25 @@ import (
 	"github.com/karmada-io/karmada/cmd/scheduler/app/options"
 	karmadaclientset "github.com/karmada-io/karmada/pkg/generated/clientset/versioned"
 	"github.com/karmada-io/karmada/pkg/scheduler"
+	"github.com/karmada-io/karmada/pkg/scheduler/framework/runtime"
 	"github.com/karmada-io/karmada/pkg/sharedcli"
 	"github.com/karmada-io/karmada/pkg/sharedcli/klogflag"
 	"github.com/karmada-io/karmada/pkg/version"
 	"github.com/karmada-io/karmada/pkg/version/sharedcommand"
 )
 
+// Option configures a framework.Registry.
+type Option func(runtime.Registry) error
+
+// WithPlugin used to register a PluginFactory.
+func WithPlugin(name string, factory runtime.PluginFactory) Option {
+	return func(r runtime.Registry) error {
+		return r.Register(name, factory)
+	}
+}
+
 // NewSchedulerCommand creates a *cobra.Command object with default parameters
-func NewSchedulerCommand(stopChan <-chan struct{}) *cobra.Command {
+func NewSchedulerCommand(stopChan <-chan struct{}, registryOptions ...Option) *cobra.Command {
 	opts := options.NewOptions()
 
 	cmd := &cobra.Command{
@@ -42,7 +53,7 @@ func NewSchedulerCommand(stopChan <-chan struct{}) *cobra.Command {
 			if errs := opts.Validate(); len(errs) != 0 {
 				return errs.ToAggregate()
 			}
-			if err := run(opts, stopChan); err != nil {
+			if err := run(opts, stopChan, registryOptions...); err != nil {
 				return err
 			}
 			return nil
@@ -75,7 +86,7 @@ func NewSchedulerCommand(stopChan <-chan struct{}) *cobra.Command {
 	return cmd
 }
 
-func run(opts *options.Options, stopChan <-chan struct{}) error {
+func run(opts *options.Options, stopChan <-chan struct{}, registryOptions ...Option) error {
 	klog.Infof("karmada-scheduler version: %s", version.Get())
 	go serveHealthzAndMetrics(net.JoinHostPort(opts.BindAddress, strconv.Itoa(opts.SecurePort)))
 
@@ -94,8 +105,15 @@ func run(opts *options.Options, stopChan <-chan struct{}) error {
 		<-stopChan
 		cancel()
 	}()
+	outOfTreeRegistry := make(runtime.Registry)
+	for _, option := range registryOptions {
+		if err := option(outOfTreeRegistry); err != nil {
+			return fmt.Errorf("register out of tree plugins error: %s", err)
+		}
+	}
 
 	sched, err := scheduler.NewScheduler(dynamicClientSet, karmadaClient, kubeClientSet,
+		scheduler.WithOutOfTreeRegistry(outOfTreeRegistry),
 		scheduler.WithEnableSchedulerEstimator(opts.EnableSchedulerEstimator),
 		scheduler.WithSchedulerEstimatorPort(opts.SchedulerEstimatorPort),
 		scheduler.WithSchedulerEstimatorTimeout(opts.SchedulerEstimatorTimeout),

pkg/scheduler/scheduler.go

@@ -34,6 +34,7 @@ import (
 	schedulercache "github.com/karmada-io/karmada/pkg/scheduler/cache"
 	"github.com/karmada-io/karmada/pkg/scheduler/core"
 	frameworkplugins "github.com/karmada-io/karmada/pkg/scheduler/framework/plugins"
+	"github.com/karmada-io/karmada/pkg/scheduler/framework/runtime"
 	"github.com/karmada-io/karmada/pkg/scheduler/metrics"
 	"github.com/karmada-io/karmada/pkg/util"
 	utilmetrics "github.com/karmada-io/karmada/pkg/util/metrics"
@@ -96,6 +97,8 @@ type schedulerOptions struct {
 	schedulerEstimatorPort int
 	//enableEmptyWorkloadPropagation represents whether allow workload with replicas 0 propagated to member clusters should be enabled
 	enableEmptyWorkloadPropagation bool
+	// outOfTreeRegistry represents the registry of out-of-tree plugins
+	outOfTreeRegistry runtime.Registry
 }
 
 // Option configures a Scheduler
@@ -129,6 +132,14 @@ func WithEnableEmptyWorkloadPropagation(enableEmptyWorkloadPropagation bool) Opt
 	}
 }
 
+// WithOutOfTreeRegistry sets the registry for out-of-tree plugins. Those plugins
+// will be appended to the default in-tree registry.
+func WithOutOfTreeRegistry(registry runtime.Registry) Option {
+	return func(o *schedulerOptions) {
+		o.outOfTreeRegistry = registry
+	}
+}
+
 // NewScheduler instantiates a scheduler
 func NewScheduler(dynamicClient dynamic.Interface, karmadaClient karmadaclientset.Interface, kubeClient kubernetes.Interface, opts ...Option) (*Scheduler, error) {
 	factory := informerfactory.NewSharedInformerFactory(karmadaClient, 0)
@@ -147,6 +158,9 @@ func NewScheduler(dynamicClient dynamic.Interface, karmadaClient karmadaclientse
 
 	// TODO(kerthcet): make plugins configurable via config file
 	registry := frameworkplugins.NewInTreeRegistry()
+	if err := registry.Merge(options.outOfTreeRegistry); err != nil {
+		return nil, err
+	}
 	algorithm, err := core.NewGenericScheduler(schedulerCache, registry)
 	if err != nil {
 		return nil, err