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/selector_spreading.go

@@ -0,0 +1,279 @@
+/*
+Copyright 2014 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 priorities
+
+import (
+	"fmt"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/kubernetes/pkg/scheduler/algorithm"
+	schedulerapi "k8s.io/kubernetes/pkg/scheduler/api"
+	"k8s.io/kubernetes/pkg/scheduler/schedulercache"
+	utilnode "k8s.io/kubernetes/pkg/util/node"
+
+	"github.com/golang/glog"
+)
+
+// When zone information is present, give 2/3 of the weighting to zone spreading, 1/3 to node spreading
+// TODO: Any way to justify this weighting?
+const zoneWeighting float64 = 2.0 / 3.0
+
+type SelectorSpread struct {
+	serviceLister     algorithm.ServiceLister
+	controllerLister  algorithm.ControllerLister
+	replicaSetLister  algorithm.ReplicaSetLister
+	statefulSetLister algorithm.StatefulSetLister
+}
+
+func NewSelectorSpreadPriority(
+	serviceLister algorithm.ServiceLister,
+	controllerLister algorithm.ControllerLister,
+	replicaSetLister algorithm.ReplicaSetLister,
+	statefulSetLister algorithm.StatefulSetLister) (algorithm.PriorityMapFunction, algorithm.PriorityReduceFunction) {
+	selectorSpread := &SelectorSpread{
+		serviceLister:     serviceLister,
+		controllerLister:  controllerLister,
+		replicaSetLister:  replicaSetLister,
+		statefulSetLister: statefulSetLister,
+	}
+	return selectorSpread.CalculateSpreadPriorityMap, selectorSpread.CalculateSpreadPriorityReduce
+}
+
+// CalculateSpreadPriorityMap spreads pods across hosts, considering pods
+// belonging to the same service,RC,RS or StatefulSet.
+// When a pod is scheduled, it looks for services, RCs,RSs and StatefulSets that match the pod,
+// then finds existing pods that match those selectors.
+// It favors nodes that have fewer existing matching pods.
+// i.e. it pushes the scheduler towards a node where there's the smallest number of
+// pods which match the same service, RC,RSs or StatefulSets selectors as the pod being scheduled.
+func (s *SelectorSpread) CalculateSpreadPriorityMap(pod *v1.Pod, meta interface{}, nodeInfo *schedulercache.NodeInfo) (schedulerapi.HostPriority, error) {
+	var selectors []labels.Selector
+	node := nodeInfo.Node()
+	if node == nil {
+		return schedulerapi.HostPriority{}, fmt.Errorf("node not found")
+	}
+
+	priorityMeta, ok := meta.(*priorityMetadata)
+	if ok {
+		selectors = priorityMeta.podSelectors
+	} else {
+		selectors = getSelectors(pod, s.serviceLister, s.controllerLister, s.replicaSetLister, s.statefulSetLister)
+	}
+
+	if len(selectors) == 0 {
+		return schedulerapi.HostPriority{
+			Host:  node.Name,
+			Score: int(0),
+		}, nil
+	}
+
+	count := int(0)
+	for _, nodePod := range nodeInfo.Pods() {
+		if pod.Namespace != nodePod.Namespace {
+			continue
+		}
+		// When we are replacing a failed pod, we often see the previous
+		// deleted version while scheduling the replacement.
+		// Ignore the previous deleted version for spreading purposes
+		// (it can still be considered for resource restrictions etc.)
+		if nodePod.DeletionTimestamp != nil {
+			glog.V(4).Infof("skipping pending-deleted pod: %s/%s", nodePod.Namespace, nodePod.Name)
+			continue
+		}
+		matches := false
+		for _, selector := range selectors {
+			if selector.Matches(labels.Set(nodePod.ObjectMeta.Labels)) {
+				matches = true
+				break
+			}
+		}
+		if matches {
+			count++
+		}
+	}
+	return schedulerapi.HostPriority{
+		Host:  node.Name,
+		Score: int(count),
+	}, nil
+}
+
+// CalculateSpreadPriorityReduce calculates the source of each node
+// based on the number of existing matching pods on the node
+// where zone information is included on the nodes, it favors nodes
+// in zones with fewer existing matching pods.
+func (s *SelectorSpread) CalculateSpreadPriorityReduce(pod *v1.Pod, meta interface{}, nodeNameToInfo map[string]*schedulercache.NodeInfo, result schedulerapi.HostPriorityList) error {
+	countsByZone := make(map[string]int, 10)
+	maxCountByZone := int(0)
+	maxCountByNodeName := int(0)
+
+	for i := range result {
+		if result[i].Score > maxCountByNodeName {
+			maxCountByNodeName = result[i].Score
+		}
+		zoneId := utilnode.GetZoneKey(nodeNameToInfo[result[i].Host].Node())
+		if zoneId == "" {
+			continue
+		}
+		countsByZone[zoneId] += result[i].Score
+	}
+
+	for zoneId := range countsByZone {
+		if countsByZone[zoneId] > maxCountByZone {
+			maxCountByZone = countsByZone[zoneId]
+		}
+	}
+
+	haveZones := len(countsByZone) != 0
+
+	maxCountByNodeNameFloat64 := float64(maxCountByNodeName)
+	maxCountByZoneFloat64 := float64(maxCountByZone)
+	MaxPriorityFloat64 := float64(schedulerapi.MaxPriority)
+
+	for i := range result {
+		// initializing to the default/max node score of maxPriority
+		fScore := MaxPriorityFloat64
+		if maxCountByNodeName > 0 {
+			fScore = MaxPriorityFloat64 * (float64(maxCountByNodeName-result[i].Score) / maxCountByNodeNameFloat64)
+		}
+		// If there is zone information present, incorporate it
+		if haveZones {
+			zoneId := utilnode.GetZoneKey(nodeNameToInfo[result[i].Host].Node())
+			if zoneId != "" {
+				zoneScore := MaxPriorityFloat64
+				if maxCountByZone > 0 {
+					zoneScore = MaxPriorityFloat64 * (float64(maxCountByZone-countsByZone[zoneId]) / maxCountByZoneFloat64)
+				}
+				fScore = (fScore * (1.0 - zoneWeighting)) + (zoneWeighting * zoneScore)
+			}
+		}
+		result[i].Score = int(fScore)
+		if glog.V(10) {
+			glog.Infof(
+				"%v -> %v: SelectorSpreadPriority, Score: (%d)", pod.Name, result[i].Host, int(fScore),
+			)
+		}
+	}
+	return nil
+}
+
+type ServiceAntiAffinity struct {
+	podLister     algorithm.PodLister
+	serviceLister algorithm.ServiceLister
+	label         string
+}
+
+func NewServiceAntiAffinityPriority(podLister algorithm.PodLister, serviceLister algorithm.ServiceLister, label string) (algorithm.PriorityMapFunction, algorithm.PriorityReduceFunction) {
+	antiAffinity := &ServiceAntiAffinity{
+		podLister:     podLister,
+		serviceLister: serviceLister,
+		label:         label,
+	}
+	return antiAffinity.CalculateAntiAffinityPriorityMap, antiAffinity.CalculateAntiAffinityPriorityReduce
+}
+
+// Classifies nodes into ones with labels and without labels.
+func (s *ServiceAntiAffinity) getNodeClassificationByLabels(nodes []*v1.Node) (map[string]string, []string) {
+	labeledNodes := map[string]string{}
+	nonLabeledNodes := []string{}
+	for _, node := range nodes {
+		if labels.Set(node.Labels).Has(s.label) {
+			label := labels.Set(node.Labels).Get(s.label)
+			labeledNodes[node.Name] = label
+		} else {
+			nonLabeledNodes = append(nonLabeledNodes, node.Name)
+		}
+	}
+	return labeledNodes, nonLabeledNodes
+}
+
+// filteredPod get pods based on namespace and selector
+func filteredPod(namespace string, selector labels.Selector, nodeInfo *schedulercache.NodeInfo) (pods []*v1.Pod) {
+	if nodeInfo.Pods() == nil || len(nodeInfo.Pods()) == 0 || selector == nil {
+		return []*v1.Pod{}
+	}
+	for _, pod := range nodeInfo.Pods() {
+		if namespace == pod.Namespace && selector.Matches(labels.Set(pod.Labels)) {
+			pods = append(pods, pod)
+		}
+	}
+	return
+}
+
+// CalculateAntiAffinityPriorityMap spreads pods by minimizing the number of pods belonging to the same service
+// on given machine
+func (s *ServiceAntiAffinity) CalculateAntiAffinityPriorityMap(pod *v1.Pod, meta interface{}, nodeInfo *schedulercache.NodeInfo) (schedulerapi.HostPriority, error) {
+	var firstServiceSelector labels.Selector
+
+	node := nodeInfo.Node()
+	if node == nil {
+		return schedulerapi.HostPriority{}, fmt.Errorf("node not found")
+	}
+	priorityMeta, ok := meta.(*priorityMetadata)
+	if ok {
+		firstServiceSelector = priorityMeta.podFirstServiceSelector
+	} else {
+		firstServiceSelector = getFirstServiceSelector(pod, s.serviceLister)
+	}
+	//pods matched namespace,selector on current node
+	matchedPodsOfNode := filteredPod(pod.Namespace, firstServiceSelector, nodeInfo)
+
+	return schedulerapi.HostPriority{
+		Host:  node.Name,
+		Score: int(len(matchedPodsOfNode)),
+	}, nil
+}
+
+// CalculateAntiAffinityPriorityReduce computes each node score with the same value for a particular label.
+// The label to be considered is provided to the struct (ServiceAntiAffinity).
+func (s *ServiceAntiAffinity) CalculateAntiAffinityPriorityReduce(pod *v1.Pod, meta interface{}, nodeNameToInfo map[string]*schedulercache.NodeInfo, result schedulerapi.HostPriorityList) error {
+	var numServicePods int
+	var label string
+	podCounts := map[string]int{}
+	labelNodesStatus := map[string]string{}
+	maxPriorityFloat64 := float64(schedulerapi.MaxPriority)
+
+	for _, hostPriority := range result {
+		numServicePods += hostPriority.Score
+		if !labels.Set(nodeNameToInfo[hostPriority.Host].Node().Labels).Has(s.label) {
+			continue
+		}
+		label = labels.Set(nodeNameToInfo[hostPriority.Host].Node().Labels).Get(s.label)
+		labelNodesStatus[hostPriority.Host] = label
+		podCounts[label] += hostPriority.Score
+	}
+
+	//score int - scale of 0-maxPriority
+	// 0 being the lowest priority and maxPriority being the highest
+	for i, hostPriority := range result {
+		label, ok := labelNodesStatus[hostPriority.Host]
+		if !ok {
+			result[i].Host = hostPriority.Host
+			result[i].Score = int(0)
+			continue
+		}
+		// initializing to the default/max node score of maxPriority
+		fScore := maxPriorityFloat64
+		if numServicePods > 0 {
+			fScore = maxPriorityFloat64 * (float64(numServicePods-podCounts[label]) / float64(numServicePods))
+		}
+		result[i].Host = hostPriority.Host
+		result[i].Score = int(fScore)
+	}
+
+	return nil
+}