// CalculateSpreadPriority spreads pods by minimizing the number of pods belonging to the same service
// on the same machine.
func (s *ServiceSpread) CalculateSpreadPriority(pod *api.Pod, podLister algorithm.PodLister, minionLister algorithm.MinionLister) (algorithm.HostPriorityList, error) {
var maxCount int
var nsServicePods []*api.Pod
services, err := s.serviceLister.GetPodServices(pod)
if err == nil {
// just use the first service and get the other pods within the service
// TODO: a separate predicate can be created that tries to handle all services for the pod
selector := labels.SelectorFromSet(services[0].Spec.Selector)
pods, err := podLister.List(selector)
if err != nil {
return nil, err
}
// consider only the pods that belong to the same namespace
for _, nsPod := range pods {
if nsPod.Namespace == pod.Namespace {
nsServicePods = append(nsServicePods, nsPod)
}
}
}
minions, err := minionLister.List()
if err != nil {
return nil, err
}
counts := map[string]int{}
if len(nsServicePods) > 0 {
for _, pod := range nsServicePods {
counts[pod.Spec.NodeName]++
// Compute the maximum number of pods hosted on any minion
if counts[pod.Spec.NodeName] > maxCount {
maxCount = counts[pod.Spec.NodeName]
}
}
}
result := []algorithm.HostPriority{}
//score int - scale of 0-10
// 0 being the lowest priority and 10 being the highest
for _, minion := range minions.Items {
// initializing to the default/max minion score of 10
fScore := float32(10)
if maxCount > 0 {
fScore = 10 * (float32(maxCount-counts[minion.Name]) / float32(maxCount))
}
result = append(result, algorithm.HostPriority{Host: minion.Name, Score: int(fScore)})
}
return result, nil
}
// MapPodsToMachines obtains a list of pods and pivots that list into a map where the keys are host names
// and the values are the list of pods running on that host.
func MapPodsToMachines(lister algorithm.PodLister) (map[string][]*api.Pod, error) {
machineToPods := map[string][]*api.Pod{}
// TODO: perform more targeted query...
pods, err := lister.List(labels.Everything())
if err != nil {
return map[string][]*api.Pod{}, err
}
pods = filterNonRunningPods(pods)
for _, scheduledPod := range pods {
host := scheduledPod.Spec.NodeName
machineToPods[host] = append(machineToPods[host], scheduledPod)
}
return machineToPods, nil
}
// CalculateAntiAffinityPriority spreads pods by minimizing the number of pods belonging to the same service
// on machines with the same value for a particular label.
// The label to be considered is provided to the struct (ServiceAntiAffinity).
func (s *ServiceAntiAffinity) CalculateAntiAffinityPriority(pod *api.Pod, podLister algorithm.PodLister, minionLister algorithm.MinionLister) (algorithm.HostPriorityList, error) {
var nsServicePods []*api.Pod
services, err := s.serviceLister.GetPodServices(pod)
if err == nil {
// just use the first service and get the other pods within the service
// TODO: a separate predicate can be created that tries to handle all services for the pod
selector := labels.SelectorFromSet(services[0].Spec.Selector)
pods, err := podLister.List(selector)
if err != nil {
return nil, err
}
// consider only the pods that belong to the same namespace
for _, nsPod := range pods {
if nsPod.Namespace == pod.Namespace {
nsServicePods = append(nsServicePods, nsPod)
}
}
}
minions, err := minionLister.List()
if err != nil {
return nil, err
}
// separate out the minions that have the label from the ones that don't
otherMinions := []string{}
labeledMinions := map[string]string{}
for _, minion := range minions.Items {
if labels.Set(minion.Labels).Has(s.label) {
label := labels.Set(minion.Labels).Get(s.label)
labeledMinions[minion.Name] = label
} else {
otherMinions = append(otherMinions, minion.Name)
}
}
podCounts := map[string]int{}
for _, pod := range nsServicePods {
label, exists := labeledMinions[pod.Spec.NodeName]
if !exists {
continue
}
podCounts[label]++
}
numServicePods := len(nsServicePods)
result := []algorithm.HostPriority{}
//score int - scale of 0-10
// 0 being the lowest priority and 10 being the highest
for minion := range labeledMinions {
// initializing to the default/max minion score of 10
fScore := float32(10)
if numServicePods > 0 {
fScore = 10 * (float32(numServicePods-podCounts[labeledMinions[minion]]) / float32(numServicePods))
}
result = append(result, algorithm.HostPriority{Host: minion, Score: int(fScore)})
}
// add the open minions with a score of 0
for _, minion := range otherMinions {
result = append(result, algorithm.HostPriority{Host: minion, Score: 0})
}
return result, nil
}