The information is received from the DRA driver plugin through a new gRPC
streaming interface. This is backwards compatible with old DRA driver kubelet
plugins, their gRPC server will return "not implemented" and that can be
handled by kubelet. Therefore no API break is needed.
However, DRA drivers need to be updated because the Go API changed. They can
return
status.New(codes.Unimplemented, "no node resource support").Err()
if they don't support the new ListAndWatchResources method and
structured parameters.
The controller in kubelet then synchronizes this information from the driver
with NodeResourceSlice objects, creating, updating and deleting them as needed.
If the resource handle has data from a structured parameter model, then we need
to pass that to the DRA driver kubelet plugin. Because Kubernetes uses
gogo/protobuf, we cannot use "optional" for that new optional field and have to
resort to "repeated" with a single repetition if present.
This is a new, backwards-compatible field.
That extending the resource.k8s.io changes the checksum of a kubelet checkpoint
is unfortunate. Updating the test cases is a stop-gap measure, the actual
solution will have to be something else before beta.
The 10 second timeout was too low. Given that the retry loop for the
kubelet itself is 90s, increasing the timeout to half of this seems
reasonable. Ideally we would pull in the variable that sets the retry
timeout to 90s and then just set our local timeout to half of that.
Unfortunately, this is not exported, so we settle (for now with just
explicitly setting it to 45s.
Signed-off-by: Kevin Klues <kklues@nvidia.com>
Combining all prepare/unprepare operations for a pod enables plugins to
optimize the execution. Plugins can continue to use the v1beta2 API for now,
but should switch. The new API is designed so that plugins which want to work
on each claim one-by-one can do so and then report errors for each claim
separately, i.e. partial success is supported.
This PR makes the NodePrepareResources() and NodeUnprepareResource()
calls of the kubeletplugin API for DynamicResourceAllocation
symmetrical. It wasn't clear how one would use the set of CDIDevices
passed back in the NodeUnprepareResource() of the v1alpha1 API, and the
new API now passes back the full ResourceHandle that was originally
passed to the Prepare() call. Passing the ResourceHandle is strictly
more informative and a plugin could always (re)derive the set of
CDIDevice from it.
This is a breaking change, but this release is scheduled to break
multiple APIs for DynamicResourceAllocation, so it makes sense to do
this now instead of later.
Signed-off-by: Kevin Klues <kklues@nvidia.com>
* add timeouts for communication with dra plugin
* move timeout constant to k8s.io/kubernetes/pkg/kubelet/cm/util
* move settings of timeout to pkg/kubelet/plugin/dra/plugin/client.go
* remove timeout constant
Dependencies need to be updated to use
github.com/container-orchestrated-devices/container-device-interface.
It's not decided yet whether we will implement Topology support
for DRA or not. Not having any toppology-related code
will help to avoid wrong impression that DRA is used as a hint
provider for the Topology Manager.
