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.
pkg/service:
There were a couple of references here just as a reminder to change the
behavior of findPort. As of v1beta3, TargetPort was always defaulted, so
we could remove findDefaultPort and related tests.
pkg/apiserver:
The tests were using versioned API codecs for some of their encoding
tests. Necessary API types had to be written and registered with the
fake versioned codecs.
pkg/kubectl:
Some tests were converted to current versions where it made sense.
This change appends the full hostname to the mirror pod name (instead of taking
the first token) so that if the hostname is overriden, we'd not be creating
unncessary name conflicts. An example would be that a user overrides the
hostnames to be "127.0.0.1" and "127.0.0.2", and both of them were resolved to
"127" for the mirror pod name suffix.
Also, because `uname -n` could return a FQDN or not, this change takes only
the first token of it as the hostname for consistency.
If a static pod changes, delete the corresponding mirror pod. When kubelet
could not see mirror pod from the API server update, it'd attemp to create a
new mirror pod with up-to-date specs.
Currently, API server is not aware of the static pods (manifests from
sources other than the API server, e.g. file and http) at all. This is
inconvenient since users cannot check the static pods through kubectl.
It is also sub-optimal because scheduler is unaware of the resource
consumption by these static pods on the node.
This change syncs the information back to the API server by creating a
mirror pod via API server for each static pod.
- Kubelet creates containers for the static pod, as it would do
normally.
- If a mirror pod gets deleted, Kubelet will re-create one. The
containers are sync'd to the static pods, so they will not be
affected.
- If a static pod gets removed from the source (e.g. manifest file
removed from the directory), the orphaned mirror pod will be deleted.
Note that because events are associated with UID, and the mirror pod has
a different UID than the original static pod, the events will not be
shown for the mirror pod when running `kubectl describe pod
<mirror_pod>`.
Justin Santa Barbara