kubectl: fix sort logic for logs

Use a separate sorting algorithm for kubectl logs that sorts from older
to newer instead of the other way that ActivePods is doing.

pkg/controller/controller_utils.go

@@ -525,6 +525,43 @@ func (f *FakePodControl) Clear() {
 	f.Templates = []api.PodTemplateSpec{}
 }
 
+// ByLogging allows custom sorting of pods so the best one can be picked for getting its logs.
+type ByLogging []*api.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[api.PodPhase]int{api.PodRunning: 0, api.PodUnknown: 1, api.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 api.IsPodReady(s[i]) != api.IsPodReady(s[j]) {
+		return api.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 api.IsPodReady(s[i]) && api.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 []*api.Pod