Move scheduler code out of plugin directory.

This moves plugin/pkg/scheduler to pkg/scheduler and
plugin/cmd/kube-scheduler to cmd/kube-scheduler.

Bulk of the work was done with gomvpkg, except for kube-scheduler main
package.

pkg/scheduler/algorithm/priorities/util/topologies.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2016 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 util
+
+import (
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+// GetNamespacesFromPodAffinityTerm returns a set of names
+// according to the namespaces indicated in podAffinityTerm.
+// If namespaces is empty it considers the given pod's namespace.
+func GetNamespacesFromPodAffinityTerm(pod *v1.Pod, podAffinityTerm *v1.PodAffinityTerm) sets.String {
+	names := sets.String{}
+	if len(podAffinityTerm.Namespaces) == 0 {
+		names.Insert(pod.Namespace)
+	} else {
+		names.Insert(podAffinityTerm.Namespaces...)
+	}
+	return names
+}
+
+// PodMatchesTermsNamespaceAndSelector returns true if the given <pod>
+// matches the namespace and selector defined by <affinityPod>`s <term>.
+func PodMatchesTermsNamespaceAndSelector(pod *v1.Pod, namespaces sets.String, selector labels.Selector) bool {
+	if !namespaces.Has(pod.Namespace) {
+		return false
+	}
+
+	if !selector.Matches(labels.Set(pod.Labels)) {
+		return false
+	}
+	return true
+}
+
+// NodesHaveSameTopologyKey checks if nodeA and nodeB have same label value with given topologyKey as label key.
+// Returns false if topologyKey is empty.
+func NodesHaveSameTopologyKey(nodeA, nodeB *v1.Node, topologyKey string) bool {
+	if len(topologyKey) == 0 {
+		return false
+	}
+
+	if nodeA.Labels == nil || nodeB.Labels == nil {
+		return false
+	}
+
+	nodeALabel, okA := nodeA.Labels[topologyKey]
+	nodeBLabel, okB := nodeB.Labels[topologyKey]
+
+	// If found label in both nodes, check the label
+	if okB && okA {
+		return nodeALabel == nodeBLabel
+	}
+
+	return false
+}
+
+type Topologies struct {
+	DefaultKeys []string
+}
+
+// NodesHaveSameTopologyKey checks if nodeA and nodeB have same label value with given topologyKey as label key.
+func (tps *Topologies) NodesHaveSameTopologyKey(nodeA, nodeB *v1.Node, topologyKey string) bool {
+	return NodesHaveSameTopologyKey(nodeA, nodeB, topologyKey)
+}