This commit wires together the graceful delete option for pods
on the Kubelet. When a pod is deleted on the API server, a
grace period is calculated that is based on the
Pod.Spec.TerminationGracePeriodInSeconds, the user's provided grace
period, or a default. The grace period can only shrink once set.
The value provided by the user (or the default) is set onto metadata
as DeletionGracePeriod.
When the Kubelet sees a pod with DeletionTimestamp set, it uses the
value of ObjectMeta.GracePeriodSeconds as the grace period
sent to Docker. When updating status, if the pod has DeletionTimestamp
set and all containers are terminated, the Kubelet will update the
status one last time and then invoke Delete(pod, grace: 0) to
clean up the pod immediately.
This generalizes the handling of containers in the
ContainerManager.
Also introduces the ability to determine how much
resources are reserved for those system containers.
This test verifies that kubelet doesn't kill non-kubelet-managed containers.
This is obsolete now since container runtime provides only the KillPod
function, and has no support for killing a container.
* Start using FakeRuntime to replace FakeDockerClient in unit tests.
* Move and adapt docker-specific tests (e.g. creating/deleting infra
containers) to manager_test.go in dockertools.
- Delete nodes when they are no longer ready and don't exist in the
cloud provider.
- Label each node with it's hostname.
- Add flag to skip node registration.
- Add a test for registering an existing node.
We recently changed `SyncPods` to filter out terminated pods at the beginning
for two reasons:
* performance: kubelet no longer keeps goroutines to checks containers for
terminated pods.
* correctness: kubelet relies on inspecting dead containers to generate
pod status. Because dead containers may get garbage collected and
kubelet does not have checkpoints yet, syncing terminated pod could
lead to modifying the status of a terminated pod.
However, even though kubelet should not *sync* the terminated pods, it
should not attempt to remove the directories and volumes for such
pods as long as they have not been deleted. This change fixes aggresive
directory removal by passing all pods (including terminated pods) to the
cleanup functions.
Per-pod workers have sufficient knowledge to determine whether a pod has
exceeded the active deadline, and they set the status at the end of each sync.
Move the active deadline check to generatePodStatus so that per pod workers
can update the pod status directly. This eliminates the possibility of a race
condition where both SyncPods and the pod worker are updating the status, which
could lead to temporary erratic pod status behavior (pod phase: failed ->
running -> failed).
Pod statuses are periodically writtien to the status manager, and status
manager sets the start time of the pod. All non-status-modifying code should
perform cache lookup and should not attempt to generate pod status on its own.
Kubelet will stop accepting new pods if it detects low disk space on root fs or fs holding docker images.
Running pods are not affected. low-diskspace-threshold-mb is used to configure the low diskspace threshold.
Yifan Gu