move inter pod affinity predicate logic to its Filter plugin

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

@@ -0,0 +1,68 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package interpodaffinity
+
+import (
+	"fmt"
+	"sync"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	schedulerlisters "k8s.io/kubernetes/pkg/scheduler/listers"
+)
+
+// Name is the name of the plugin used in the plugin registry and configurations.
+const Name = "InterPodAffinity"
+
+// Args holds the args that are used to configure the plugin.
+type Args struct {
+	HardPodAffinityWeight int32 `json:"hardPodAffinityWeight,omitempty"`
+}
+
+var _ framework.PreFilterPlugin = &InterPodAffinity{}
+var _ framework.FilterPlugin = &InterPodAffinity{}
+var _ framework.PostFilterPlugin = &InterPodAffinity{}
+var _ framework.ScorePlugin = &InterPodAffinity{}
+
+// InterPodAffinity is a plugin that checks inter pod affinity
+type InterPodAffinity struct {
+	sharedLister          schedulerlisters.SharedLister
+	hardPodAffinityWeight int32
+	sync.Mutex
+}
+
+// Name returns name of the plugin. It is used in logs, etc.
+func (pl *InterPodAffinity) Name() string {
+	return Name
+}
+
+// New initializes a new plugin and returns it.
+func New(plArgs *runtime.Unknown, h framework.FrameworkHandle) (framework.Plugin, error) {
+	if h.SnapshotSharedLister() == nil {
+		return nil, fmt.Errorf("SnapshotSharedlister is nil")
+	}
+
+	args := &Args{}
+	if err := framework.DecodeInto(plArgs, args); err != nil {
+		return nil, err
+	}
+
+	return &InterPodAffinity{
+		sharedLister:          h.SnapshotSharedLister(),
+		hardPodAffinityWeight: args.HardPodAffinityWeight,
+	}, nil
+}