Before this change we have a mish-mash of ways to pass field names around for
error generation. Sometimes string fieldnames, sometimes .Prefix(), sometimes
neither, often wrong names or not indexed when it should be.
Instead of that mess, this is part one of a couple of commits that will make it
more strongly typed and hopefully encourage correct behavior. At least you
will have to think about field names, which is better than nothing.
It turned out to be really hard to do this incrementally.
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.
If a client says they want the name to be generated, a 409 is
not appropriate (since they didn't specify a name). Instead, we
should return the next most appropriate error, which is a 5xx
error indicating the request failed but the client *should* try
again. Since there is no 5xx error that exactly fits this purpose,
use 500 with StatusReasonTryAgainLater set.
This commit does not implement client retry on TryAgainLater, but
clients should retry up to a certain number of times.
Adds `ObjectMeta.GenerateName`, an optional string field that defines
name generation behavior if a Name is not provided.
Adds `pkg/api/rest`, which defines the default Kubernetes API pattern
for creation (and will cover update as well). Will allow registries
and REST objects to be merged by moving logic on api out of those places.
Add `pkg/api/rest/resttest`, which will be the test suite that verifies
a RESTStorage object follows the Kubernetes API conventions and begin
reducing our duplicated tests.
Clayton Coleman