This commit adds support to core resources to enable deferred deletion
of resources. Clients may optionally specify a time period after which
resources must be deleted via an object sent with their DELETE. That
object may define an optional grace period in seconds, or allow the
default "preferred" value for a resource to be used. Once the object
is marked as pending deletion, the deletionTimestamp field will be set
and an etcd TTL will be in place.
Clients should assume resources that have deletionTimestamp set will
be deleted at some point in the future. Other changes will come later
to enable graceful deletion on a per resource basis.
We decided to get rid of boundPods. Removing this check is
a prerequisite for that. This check had some value before we had
IP-per-Pod. However, AIUI, use of HostPort is strongly discouraged
in Kubernetes. It still exists as part of a Pod spec because
of ContainerVM, where it is used. But, this change does not affect
ContainerVM, where there is no master.
If someone did create pods with HostPort using kubernetes, the following
would happen:
- The scheduler would try not to put two conflicting pods on the same
machine (pkg/scheduler/predicates.go : PodFitsPorts() )
- I'm not sure if it is currently possible for a race to occur where
the PodFitsPorts check were bypassed. Maybe it could happen.
- If the kubelet was sent conflicting pods, it would detect them in
( pkg/kubelet/kubelet.go : filterHostPortConflicts() ). It would
arbitrarily pick one pod to run and another to ignore.
- If all of the above happened and the user filed and issue on github,
we might figure out that the user used HostPort and tell the user to stop.
TODO:
- e2e test
- Several of the demos in examples/ use hostPort. Change them to
not specify hostPort and have a service instead.
Allows POST to create a binding as a child. Also refactors internal
and v1beta3 Binding to be more generic (so that other resources can
support Bindings).
PUT /api/v1beta3/namespaces/default/pods/foo/status
{
"metadata": {...}, // allowed for valid values
"spec": {}, // ignored
"status": {...}, // allowed, except for Host
}
Exposes the simplest possibly change. Needs a slight refactoring
to RESTUpdateStrategy to split merging which can be done in a
follow up.
