Since it takes a while (1-2mins) for kubelet to pulling a big image
(>500MB). Just showing "Pending" for pod status is not very helpful.
This commit introduces a "pulling" event, and inserts it before the
kubelet starts to pull an image.
/runningpods returns a list of pods currently running on the kubelet. The list
is composed by examining the container runtime, and may be different from the
desired pods to run known by kubelet.
This is useful for tests to verify that pods are indeed deleted on nodes.
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.
* 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.
If a pod worker sees stale pods from the runtime cache which were retrieved
before their last sync finished, it may think that the pod were not started
correctly, and attemp to fix that by killing/restarting containers.
There are two issues that may cause runtime cache to store stale pods:
1. The timstamp is recorded *after* getting the pods from the container
runtime. This may lead the consumer to think the pods are newer than they
actually are.
2. The cache updates are triggered by many goroutines (pod workers, and the
updating thread). There is no mechanism to enforece that the cache would
only be updated to newer pods.
This change fixes the above two issues by making sure one always record the
timestamp before getting pods from the container runtime, and updates the
cached pods only if the timestamp is newer.
This change is part of the efforts to make DockerManager implement the Runtime
interface.
The change also modifies the interface slightly to work with existing
code, and aggregates the type converting functions to convert.go.
Chao Xu