add plugin clusterLocality to favor cluster

Signed-off-by: huone1 <huwanxing@huawei.com>

pkg/scheduler/framework/interface.go

@@ -10,6 +10,14 @@ import (
 	workv1alpha2 "github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
 )
 
+const (
+	// MinClusterScore is the minimum score a Score plugin is expected to return.
+	MinClusterScore int64 = 0
+
+	// MaxClusterScore is the maximum score a Score plugin is expected to return.
+	MaxClusterScore int64 = 100
+)
+
 // Framework manages the set of plugins in use by the scheduling framework.
 // Configured plugins are called at specified points in a scheduling context.
 type Framework interface {

pkg/scheduler/framework/plugins/clusteraffinity/cluster_affinity.go

@@ -48,7 +48,7 @@ func (p *ClusterAffinity) Filter(ctx context.Context, placement *policyv1alpha1.
 // Score calculates the score on the candidate cluster.
 func (p *ClusterAffinity) Score(ctx context.Context, placement *policyv1alpha1.Placement,
 	spec *workv1alpha2.ResourceBindingSpec, cluster *clusterv1alpha1.Cluster) (int64, *framework.Result) {
-	return 0, framework.NewResult(framework.Success)
+	return framework.MinClusterScore, framework.NewResult(framework.Success)
 }
 
 // ScoreExtensions of the Score plugin.

pkg/scheduler/framework/plugins/clusterlocality/cluster_locality.go

@@ -0,0 +1,66 @@
+package clusterlocality
+
+import (
+	"context"
+
+	clusterv1alpha1 "github.com/karmada-io/karmada/pkg/apis/cluster/v1alpha1"
+	policyv1alpha1 "github.com/karmada-io/karmada/pkg/apis/policy/v1alpha1"
+	workv1alpha2 "github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
+	"github.com/karmada-io/karmada/pkg/scheduler/framework"
+	"github.com/karmada-io/karmada/pkg/util"
+)
+
+const (
+	// Name is the name of the plugin used in the plugin registry and configurations.
+	Name = "ClusterLocality"
+)
+
+// ClusterLocality is a score plugin that favors cluster that already have requested.
+type ClusterLocality struct{}
+
+var _ framework.ScorePlugin = &ClusterLocality{}
+
+// New instantiates the clusteraffinity plugin.
+func New() framework.Plugin {
+	return &ClusterLocality{}
+}
+
+// Name returns the plugin name.
+func (p *ClusterLocality) Name() string {
+	return Name
+}
+
+// Score calculates the score on the candidate cluster.
+// if cluster object is exist in resourceBinding.Spec.Clusters, Score is 100, otherwise it is 0.
+func (p *ClusterLocality) Score(ctx context.Context, placement *policyv1alpha1.Placement,
+	spec *workv1alpha2.ResourceBindingSpec, cluster *clusterv1alpha1.Cluster) (int64, *framework.Result) {
+	if len(spec.Clusters) == 0 {
+		return framework.MinClusterScore, framework.NewResult(framework.Success)
+	}
+
+	replicas := util.GetSumOfReplicas(spec.Clusters)
+	if replicas <= 0 {
+		return framework.MinClusterScore, framework.NewResult(framework.Success)
+	}
+
+	if isClusterScheduled(cluster.Name, spec.Clusters) {
+		return framework.MaxClusterScore, framework.NewResult(framework.Success)
+	}
+
+	return framework.MinClusterScore, framework.NewResult(framework.Success)
+}
+
+// ScoreExtensions of the Score plugin.
+func (p *ClusterLocality) ScoreExtensions() framework.ScoreExtensions {
+	return nil
+}
+
+func isClusterScheduled(candidate string, schedulerClusters []workv1alpha2.TargetCluster) bool {
+	for _, cluster := range schedulerClusters {
+		if candidate == cluster.Name {
+			return true
+		}
+	}
+
+	return false
+}

pkg/scheduler/framework/plugins/registry.go

@@ -4,6 +4,7 @@ import (
 	"github.com/karmada-io/karmada/pkg/scheduler/framework"
 	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/apiinstalled"
 	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/clusteraffinity"
+	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/clusterlocality"
 	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/tainttoleration"
 )
 
@@ -13,5 +14,6 @@ func NewPlugins() map[string]framework.Plugin {
 		clusteraffinity.Name: clusteraffinity.New(),
 		tainttoleration.Name: tainttoleration.New(),
 		apiinstalled.Name:    apiinstalled.New(),
+		clusterlocality.Name: clusterlocality.New(),
 	}
 }

pkg/scheduler/scheduler.go

@@ -36,6 +36,7 @@ import (
 	"github.com/karmada-io/karmada/pkg/scheduler/core"
 	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/apiinstalled"
 	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/clusteraffinity"
+	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/clusterlocality"
 	"github.com/karmada-io/karmada/pkg/scheduler/framework/plugins/tainttoleration"
 	"github.com/karmada-io/karmada/pkg/scheduler/metrics"
 	"github.com/karmada-io/karmada/pkg/util"
@@ -99,7 +100,7 @@ func NewScheduler(dynamicClient dynamic.Interface, karmadaClient karmadaclientse
 	queue := workqueue.NewRateLimitingQueue(workqueue.DefaultControllerRateLimiter())
 	schedulerCache := schedulercache.NewCache(clusterLister)
 	// TODO: make plugins as a flag
-	algorithm := core.NewGenericScheduler(schedulerCache, []string{clusteraffinity.Name, tainttoleration.Name, apiinstalled.Name})
+	algorithm := core.NewGenericScheduler(schedulerCache, []string{clusteraffinity.Name, tainttoleration.Name, apiinstalled.Name, clusterlocality.Name})
 	sched := &Scheduler{
 		DynamicClient:            dynamicClient,
 		KarmadaClient:            karmadaClient,