feat(scheduler): implement node affinity as score plugin

pkg/scheduler/framework/plugins/nodeaffinity/node_affinity.go

@@ -18,19 +18,24 @@ package nodeaffinity
 
 import (
 	"context"
+	"fmt"
 
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/kubernetes/pkg/scheduler/algorithm/predicates"
+	"k8s.io/kubernetes/pkg/scheduler/algorithm/priorities"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/migration"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
 	"k8s.io/kubernetes/pkg/scheduler/nodeinfo"
 )
 
 // NodeAffinity is a plugin that checks if a pod node selector matches the node label.
-type NodeAffinity struct{}
+type NodeAffinity struct {
+	handle framework.FrameworkHandle
+}
 
-var _ = framework.FilterPlugin(&NodeAffinity{})
+var _ framework.FilterPlugin = &NodeAffinity{}
+var _ framework.ScorePlugin = &NodeAffinity{}
 
 // Name is the name of the plugin used in the plugin registry and configurations.
 const Name = "NodeAffinity"
@@ -41,12 +46,36 @@ func (pl *NodeAffinity) Name() string {
 }
 
 // Filter invoked at the filter extension point.
-func (pl *NodeAffinity) Filter(ctx context.Context, _ *framework.CycleState, pod *v1.Pod, nodeInfo *nodeinfo.NodeInfo) *framework.Status {
+func (pl *NodeAffinity) Filter(ctx context.Context, state *framework.CycleState, pod *v1.Pod, nodeInfo *nodeinfo.NodeInfo) *framework.Status {
 	_, reasons, err := predicates.PodMatchNodeSelector(pod, nil, nodeInfo)
 	return migration.PredicateResultToFrameworkStatus(reasons, err)
 }
 
-// New initializes a new plugin and returns it.
-func New(_ *runtime.Unknown, _ framework.FrameworkHandle) (framework.Plugin, error) {
-	return &NodeAffinity{}, nil
+// Score invoked at the Score extension point.
+func (pl *NodeAffinity) Score(ctx context.Context, state *framework.CycleState, pod *v1.Pod, nodeName string) (int64, *framework.Status) {
+	nodeInfo, exist := pl.handle.NodeInfoSnapshot().NodeInfoMap[nodeName]
+	if !exist {
+		return 0, framework.NewStatus(framework.Error, fmt.Sprintf("node %q does not exist in NodeInfoSnapshot", nodeName))
+	}
+
+	meta := migration.PriorityMetadata(state)
+	s, err := priorities.CalculateNodeAffinityPriorityMap(pod, meta, nodeInfo)
+	return s.Score, migration.ErrorToFrameworkStatus(err)
+}
+
+// NormalizeScore invoked after scoring all nodes.
+func (pl *NodeAffinity) NormalizeScore(ctx context.Context, state *framework.CycleState, pod *v1.Pod, scores framework.NodeScoreList) *framework.Status {
+	// Note that CalculateNodeAffinityPriorityReduce doesn't use priority metadata, hence passing nil here.
+	err := priorities.CalculateNodeAffinityPriorityReduce(pod, nil, pl.handle.NodeInfoSnapshot().NodeInfoMap, scores)
+	return migration.ErrorToFrameworkStatus(err)
+}
+
+// ScoreExtensions of the Score plugin.
+func (pl *NodeAffinity) ScoreExtensions() framework.ScoreExtensions {
+	return pl
+}
+
+// New initializes a new plugin and returns it.
+func New(_ *runtime.Unknown, h framework.FrameworkHandle) (framework.Plugin, error) {
+	return &NodeAffinity{handle: h}, nil
 }