diff --git a/pkg/util/podutils/podutils.go b/pkg/util/podutils/podutils.go new file mode 100644 index 00000000..142b8879 --- /dev/null +++ b/pkg/util/podutils/podutils.go @@ -0,0 +1,190 @@ +/* +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 podutils + +import ( + "time" + + corev1 "k8s.io/api/core/v1" + metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" + "k8s.io/utils/integer" +) + +// IsPodAvailable returns true if a pod is available; false otherwise. +// Precondition for an available pod is that it must be ready. On top +// of that, there are two cases when a pod can be considered available: +// 1. minReadySeconds == 0, or +// 2. LastTransitionTime (is set) + minReadySeconds < current time +func IsPodAvailable(pod *corev1.Pod, minReadySeconds int32, now metav1.Time) bool { + if !IsPodReady(pod) { + return false + } + + c := getPodReadyCondition(pod.Status) + minReadySecondsDuration := time.Duration(minReadySeconds) * time.Second + if minReadySeconds == 0 || !c.LastTransitionTime.IsZero() && c.LastTransitionTime.Add(minReadySecondsDuration).Before(now.Time) { + return true + } + return false +} + +// IsPodReady returns true if a pod is ready; false otherwise. +func IsPodReady(pod *corev1.Pod) bool { + return isPodReadyConditionTrue(pod.Status) +} + +// IsPodReadyConditionTrue returns true if a pod is ready; false otherwise. +func isPodReadyConditionTrue(status corev1.PodStatus) bool { + condition := getPodReadyCondition(status) + return condition != nil && condition.Status == corev1.ConditionTrue +} + +// GetPodReadyCondition extracts the pod ready condition from the given status and returns that. +// Returns nil if the condition is not present. +func getPodReadyCondition(status corev1.PodStatus) *corev1.PodCondition { + _, condition := getPodCondition(&status, corev1.PodReady) + return condition +} + +// GetPodCondition extracts the provided condition from the given status and returns that. +// Returns nil and -1 if the condition is not present, and the index of the located condition. +func getPodCondition(status *corev1.PodStatus, conditionType corev1.PodConditionType) (int, *corev1.PodCondition) { + if status == nil { + return -1, nil + } + return getPodConditionFromList(status.Conditions, conditionType) +} + +// GetPodConditionFromList extracts the provided condition from the given list of condition and +// returns the index of the condition and the condition. Returns -1 and nil if the condition is not present. +func getPodConditionFromList(conditions []corev1.PodCondition, conditionType corev1.PodConditionType) (int, *corev1.PodCondition) { + if conditions == nil { + return -1, nil + } + for i := range conditions { + if conditions[i].Type == conditionType { + return i, &conditions[i] + } + } + return -1, nil +} + +// ByLogging allows custom sorting of pods so the best one can be picked for getting its logs. +type ByLogging []*corev1.Pod + +func (s ByLogging) Len() int { return len(s) } +func (s ByLogging) Swap(i, j int) { s[i], s[j] = s[j], s[i] } + +func (s ByLogging) Less(i, j int) bool { + // 1. assigned < unassigned + if s[i].Spec.NodeName != s[j].Spec.NodeName && (len(s[i].Spec.NodeName) == 0 || len(s[j].Spec.NodeName) == 0) { + return len(s[i].Spec.NodeName) > 0 + } + // 2. PodRunning < PodUnknown < PodPending + m := map[corev1.PodPhase]int{corev1.PodRunning: 0, corev1.PodUnknown: 1, corev1.PodPending: 2} + if m[s[i].Status.Phase] != m[s[j].Status.Phase] { + return m[s[i].Status.Phase] < m[s[j].Status.Phase] + } + // 3. ready < not ready + if IsPodReady(s[i]) != IsPodReady(s[j]) { + return IsPodReady(s[i]) + } + // TODO: take availability into account when we push minReadySeconds information from deployment into pods, + // see https://github.com/kubernetes/kubernetes/issues/22065 + // 4. Been ready for more time < less time < empty time + if IsPodReady(s[i]) && IsPodReady(s[j]) && !podReadyTime(s[i]).Equal(podReadyTime(s[j])) { + return afterOrZero(podReadyTime(s[j]), podReadyTime(s[i])) + } + // 5. Pods with containers with higher restart counts < lower restart counts + if maxContainerRestarts(s[i]) != maxContainerRestarts(s[j]) { + return maxContainerRestarts(s[i]) > maxContainerRestarts(s[j]) + } + // 6. older pods < newer pods < empty timestamp pods + if !s[i].CreationTimestamp.Equal(&s[j].CreationTimestamp) { + return afterOrZero(&s[j].CreationTimestamp, &s[i].CreationTimestamp) + } + return false +} + +// ActivePods type allows custom sorting of pods so a controller can pick the best ones to delete. +type ActivePods []*corev1.Pod + +func (s ActivePods) Len() int { return len(s) } +func (s ActivePods) Swap(i, j int) { s[i], s[j] = s[j], s[i] } + +func (s ActivePods) Less(i, j int) bool { + // 1. Unassigned < assigned + // If only one of the pods is unassigned, the unassigned one is smaller + if s[i].Spec.NodeName != s[j].Spec.NodeName && (len(s[i].Spec.NodeName) == 0 || len(s[j].Spec.NodeName) == 0) { + return len(s[i].Spec.NodeName) == 0 + } + // 2. PodPending < PodUnknown < PodRunning + m := map[corev1.PodPhase]int{corev1.PodPending: 0, corev1.PodUnknown: 1, corev1.PodRunning: 2} + if m[s[i].Status.Phase] != m[s[j].Status.Phase] { + return m[s[i].Status.Phase] < m[s[j].Status.Phase] + } + // 3. Not ready < ready + // If only one of the pods is not ready, the not ready one is smaller + if IsPodReady(s[i]) != IsPodReady(s[j]) { + return !IsPodReady(s[i]) + } + // TODO: take availability into account when we push minReadySeconds information from deployment into pods, + // see https://github.com/kubernetes/kubernetes/issues/22065 + // 4. Been ready for empty time < less time < more time + // If both pods are ready, the latest ready one is smaller + if IsPodReady(s[i]) && IsPodReady(s[j]) && !podReadyTime(s[i]).Equal(podReadyTime(s[j])) { + return afterOrZero(podReadyTime(s[i]), podReadyTime(s[j])) + } + // 5. Pods with containers with higher restart counts < lower restart counts + if maxContainerRestarts(s[i]) != maxContainerRestarts(s[j]) { + return maxContainerRestarts(s[i]) > maxContainerRestarts(s[j]) + } + // 6. Empty creation time pods < newer pods < older pods + if !s[i].CreationTimestamp.Equal(&s[j].CreationTimestamp) { + return afterOrZero(&s[i].CreationTimestamp, &s[j].CreationTimestamp) + } + return false +} + +// afterOrZero checks if time t1 is after time t2; if one of them +// is zero, the zero time is seen as after non-zero time. +func afterOrZero(t1, t2 *metav1.Time) bool { + if t1.Time.IsZero() || t2.Time.IsZero() { + return t1.Time.IsZero() + } + return t1.After(t2.Time) +} + +func podReadyTime(pod *corev1.Pod) *metav1.Time { + if IsPodReady(pod) { + for _, c := range pod.Status.Conditions { + // we only care about pod ready conditions + if c.Type == corev1.PodReady && c.Status == corev1.ConditionTrue { + return &c.LastTransitionTime + } + } + } + return &metav1.Time{} +} + +func maxContainerRestarts(pod *corev1.Pod) int { + maxRestarts := 0 + for _, c := range pod.Status.ContainerStatuses { + maxRestarts = integer.IntMax(maxRestarts, int(c.RestartCount)) + } + return maxRestarts +}