kubernetes 中 Evicted pod 是如何产生的

$ kubectl get pod | grep -i Evicted
cloud-1023955-84421-49604-5-deploy-c-7748f8fd8-hjqsh        0/1     Evicted   0          73d
cloud-1023955-84421-49604-5-deploy-c-7748f8fd8-mzd8x        0/1     Evicted   0          81d
cloud-1237162-276467-199844-2-deploy-7bdc7c98b6-26r2r       0/1     Evicted   0          18d

status:
  message: 'Pod The node had condition: [DiskPressure]. '
  phase: Failed
  reason: Evicted
  startTime: "2021-09-14T10:42:32Z"

#!/bin/bash
#!/usr/bin/env bash

# This script reproduces what the kubelet does
# to calculate memory.available relative to root cgroup.

# current memory usage
memory_capacity_in_kb=$(cat /proc/meminfo | grep MemTotal | awk '{print $2}')
memory_capacity_in_bytes=$((memory_capacity_in_kb * 1024))
memory_usage_in_bytes=$(cat /sys/fs/cgroup/memory/memory.usage_in_bytes)
memory_total_inactive_file=$(cat /sys/fs/cgroup/memory/memory.stat | grep total_inactive_file | awk '{print $2}')

memory_working_set=${memory_usage_in_bytes}
if [ "$memory_working_set" -lt "$memory_total_inactive_file" ];
then
    memory_working_set=0
else
    memory_working_set=$((memory_usage_in_bytes - memory_total_inactive_file))
fi

memory_available_in_bytes=$((memory_capacity_in_bytes - memory_working_set))
memory_available_in_kb=$((memory_available_in_bytes / 1024))
memory_available_in_mb=$((memory_available_in_kb / 1024))

echo "memory.capacity_in_bytes $memory_capacity_in_bytes"
echo "memory.usage_in_bytes $memory_usage_in_bytes"
echo "memory.total_inactive_file $memory_total_inactive_file"
echo "memory.working_set $memory_working_set"
echo "memory.available_in_bytes $memory_available_in_bytes"
echo "memory.available_in_kb $memory_available_in_kb"
echo "memory.available_in_mb $memory_available_in_mb"

// Examine each replica with respect to its ordinal
for i := range replicas {
    // delete and recreate failed pods
    if isFailed(replicas[i]) {
        ssc.recorder.Eventf(set, v1.EventTypeWarning, "RecreatingFailedPod",
            "StatefulSet %s/%s is recreating failed Pod %s",
            set.Namespace,
            set.Name,
            replicas[i].Name)
        if err := ssc.podControl.DeleteStatefulPod(set, replicas[i]); err != nil {
            return &status, err
        }
        if getPodRevision(replicas[i]) == currentRevision.Name {
            status.CurrentReplicas--
        }
        if getPodRevision(replicas[i]) == updateRevision.Name {
            status.UpdatedReplicas--
        }
        ......

func (dsc *DaemonSetsController) podsShouldBeOnNode(
		......
) (nodesNeedingDaemonPods, podsToDelete []string) {

		......

    switch {
		......
    case shouldContinueRunning:
				......
        for _, pod := range daemonPods {
            if pod.DeletionTimestamp != nil {
                continue
            }
            if pod.Status.Phase == v1.PodFailed {
                // This is a critical place where DS is often fighting with kubelet that rejects pods.
                // We need to avoid hot looping and backoff.
                backoffKey := failedPodsBackoffKey(ds, node.Name)
                ......

const (
	podEvictedStatus = "Evicted"
)

// 判断如果为 Evicted 状态的实例且 Pod 中容器数为 0 时直接删除 pod
if strings.ToLower(status) == strings.ToLower(podEvictedStatus) && len(pod.Status.ContainerStatuses) == 0 {
	
}

Podgc controller flags:

      --terminated-pod-gc-threshold int32
                Number of terminated pods that can exist before the terminated pod garbage collector starts deleting terminated pods. If
                <= 0, the terminated pod garbage collector is disabled. (default 12500)