Cleanup and prepare for optimizing PodAffinity priority function.

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

@@ -0,0 +1,95 @@
+/*
+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/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/unversioned"
+	"k8s.io/kubernetes/pkg/labels"
+	"k8s.io/kubernetes/pkg/util/sets"
+)
+
+// FilterPodsByNameSpaces filters the pods based the given list of namespaces,
+// empty set of namespaces means all namespaces.
+func FilterPodsByNameSpaces(names sets.String, pods []*api.Pod) []*api.Pod {
+	if len(pods) == 0 || len(names) == 0 {
+		return pods
+	}
+	result := []*api.Pod{}
+	for _, pod := range pods {
+		if names.Has(pod.Namespace) {
+			result = append(result, pod)
+		}
+	}
+	return result
+}
+
+// GetNamespacesFromPodAffinityTerm returns a set of names
+// according to the namespaces indicated in podAffinityTerm.
+// if the NameSpaces is nil considers the given pod's namespace
+// if the Namespaces is empty list then considers all the namespaces
+func GetNamespacesFromPodAffinityTerm(pod *api.Pod, podAffinityTerm api.PodAffinityTerm) sets.String {
+	names := sets.String{}
+	if podAffinityTerm.Namespaces == nil {
+		names.Insert(pod.Namespace)
+	} else if len(podAffinityTerm.Namespaces) != 0 {
+		names.Insert(podAffinityTerm.Namespaces...)
+	}
+	return names
+}
+
+// nodesHaveSameTopologyKeyInternal checks if nodeA and nodeB have same label value with given topologyKey as label key.
+func nodesHaveSameTopologyKeyInternal(nodeA, nodeB *api.Node, topologyKey string) bool {
+	return nodeA.Labels != nil && nodeB.Labels != nil && len(nodeA.Labels[topologyKey]) > 0 && nodeA.Labels[topologyKey] == nodeB.Labels[topologyKey]
+}
+
+type Topologies struct {
+	DefaultKeys []string
+}
+
+// NodesHaveSameTopologyKey checks if nodeA and nodeB have same label value with given topologyKey as label key.
+// If the topologyKey is nil/empty, check if the two nodes have any of the default topologyKeys, and have same corresponding label value.
+func (tps *Topologies) NodesHaveSameTopologyKey(nodeA, nodeB *api.Node, topologyKey string) bool {
+	if len(topologyKey) == 0 {
+		// assumes this is allowed only for PreferredDuringScheduling pod anti-affinity (ensured by api/validation)
+		for _, defaultKey := range tps.DefaultKeys {
+			if nodesHaveSameTopologyKeyInternal(nodeA, nodeB, defaultKey) {
+				return true
+			}
+		}
+		return false
+	} else {
+		return nodesHaveSameTopologyKeyInternal(nodeA, nodeB, topologyKey)
+	}
+}
+
+// CheckIfPodMatchPodAffinityTerm checks if podB's affinity request is compatible with podA
+// TODO: Get rid this method. We should avoid computing Namespaces and selectors multiple times
+// and check them on higher levels and then use NodesHaveSameTopologyKey method.
+func (tps *Topologies) CheckIfPodMatchPodAffinityTerm(podA *api.Pod, nodeA, nodeB *api.Node, podB *api.Pod, podBAffinityTerm api.PodAffinityTerm) (bool, error) {
+	names := GetNamespacesFromPodAffinityTerm(podB, podBAffinityTerm)
+	if len(names) != 0 && !names.Has(podA.Namespace) {
+		return false, nil
+	}
+
+	labelSelector, err := unversioned.LabelSelectorAsSelector(podBAffinityTerm.LabelSelector)
+	if err != nil || !labelSelector.Matches(labels.Set(podA.Labels)) {
+		return false, err
+	}
+
+	return tps.NodesHaveSameTopologyKey(nodeA, nodeB, podBAffinityTerm.TopologyKey), nil
+}