fix: update scheduler to support customized cluster affinity plugin (#330)

fix scheduler for future implementation

Signed-off-by: Britania Rodriguez Reyes <britaniar@microsoft.com>

Author: britaniar

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

@@ -59,7 +59,9 @@ func (p *Plugin) Filter(
 
 	for idx := range ps.GetPolicySnapshotSpec().Policy.Affinity.ClusterAffinity.RequiredDuringSchedulingIgnoredDuringExecution.ClusterSelectorTerms {
 		t := &ps.GetPolicySnapshotSpec().Policy.Affinity.ClusterAffinity.RequiredDuringSchedulingIgnoredDuringExecution.ClusterSelectorTerms[idx]
-		r := clusterRequirement(*t)
+		r := clusterRequirement{
+			ClusterSelectorTerm: *t,
+		}
 		isMatched, err := r.Matches(cluster)
 		if err != nil {
 			// An error has occurred when matching the cluster against a required affinity term.

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

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// Package clusteraffinity features a scheduler plugin that enforces cluster affinity (if any) defined on a CRP.
+// Package clusteraffinity features a scheduler plugin that enforces cluster affinity (if any) defined on a RP/CRP.
 package clusteraffinity
 
 import (
@@ -24,7 +24,7 @@ import (
 	"github.com/kubefleet-dev/kubefleet/pkg/scheduler/framework"
 )
 
-// Plugin is the scheduler plugin that enforces the cluster affinity (if any) defined on a CRP.
+// Plugin is the scheduler plugin that enforces the cluster affinity (if any) defined on a R/CRP.
 type Plugin struct {
 	// The name of the plugin.
 	name string

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

@@ -33,7 +33,10 @@ import (
 
 // clusterRequirement is a type alias for ClusterSelectorTerm in the API, which allows
 // easy method extension.
-type clusterRequirement placementv1beta1.ClusterSelectorTerm
+type clusterRequirement struct {
+	// Embed the original ClusterSelectorTerm.
+	ClusterSelectorTerm placementv1beta1.ClusterSelectorTerm
+}
 
 // retrieveResourceUsageFrom retrieves a resource property value from a member cluster.
 //
@@ -121,8 +124,8 @@ func retrievePropertyValueFrom(cluster *clusterv1beta1.MemberCluster, name strin
 // This is an extended method for the ClusterSelectorTerm API.
 func (c *clusterRequirement) Matches(cluster *clusterv1beta1.MemberCluster) (bool, error) {
 	// Match the cluster against the label selector.
-	if c.LabelSelector != nil {
-		ls, err := metav1.LabelSelectorAsSelector(c.LabelSelector)
+	if c.ClusterSelectorTerm.LabelSelector != nil {
+		ls, err := metav1.LabelSelectorAsSelector(c.ClusterSelectorTerm.LabelSelector)
 		if err != nil {
 			return false, fmt.Errorf("failed to parse label selector: %w", err)
 		}
@@ -134,12 +137,12 @@ func (c *clusterRequirement) Matches(cluster *clusterv1beta1.MemberCluster) (boo
 	}
 
 	// Match the cluster against the property selector.
-	if c.PropertySelector == nil || len(c.PropertySelector.MatchExpressions) == 0 {
+	if c.ClusterSelectorTerm.PropertySelector == nil || len(c.ClusterSelectorTerm.PropertySelector.MatchExpressions) == 0 {
 		// The term does not feature a property selector; no check is needed.
 		return true, nil
 	}
 
-	for _, exp := range c.PropertySelector.MatchExpressions {
+	for _, exp := range c.ClusterSelectorTerm.PropertySelector.MatchExpressions {
 		// Compare the observed value with the expected one using the specified operator.
 		q, err := retrievePropertyValueFrom(cluster, exp.Name)
 		if err != nil {