Move pkg/kubectl/util/podutils to staging

Kubernetes-commit: 4c58308b4e646be92f69dec772d70e81c1541148

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
+}