kubelet: support batched prepare/unprepare in v1alpha3 DRA plugin API

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.

Kubernetes-commit: d743c50bb9e663809e0129ee058fabdcf59d3d27

pkg/apis/dra/v1alpha3/api.proto

@@ -0,0 +1,103 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// To regenerate api.pb.go run `hack/update-codegen.sh protobindings`
+
+syntax = "proto3";
+
+package v1alpha3;
+option go_package = "k8s.io/kubelet/pkg/apis/dra/v1alpha3";
+
+import "github.com/gogo/protobuf/gogoproto/gogo.proto";
+
+option (gogoproto.goproto_stringer_all) = false;
+option (gogoproto.stringer_all) =  true;
+option (gogoproto.goproto_getters_all) = true;
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.sizer_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+option (gogoproto.goproto_unrecognized_all) = false;
+
+service Node {
+  // NodePrepareResources prepares several ResourceClaims
+  // for use on the node. If an error is returned, the
+  // response is ignored. Failures for individidual claims
+  // can be reported inside NodePrepareResourcesResponse.
+  rpc NodePrepareResources (NodePrepareResourcesRequest)
+    returns (NodePrepareResourcesResponse) {}
+
+  // NodeUnprepareResources is the opposite of NodePrepareResources.
+  // The same error handling rules apply,
+  rpc NodeUnprepareResources (NodeUnprepareResourcesRequest)
+    returns (NodeUnprepareResourcesResponse) {}
+}
+
+message NodePrepareResourcesRequest {
+     // The list of ResourceClaims that are to be prepared.
+     repeated Claim claims = 1;
+}
+
+message NodePrepareResourcesResponse {
+    // The ResourceClaims for which preparation was done
+    // or attempted, with claim_uid as key.
+    //
+    // It is an error if some claim listed in NodePrepareResourcesRequest
+    // does not get prepared. NodePrepareResources
+    // will be called again for those that are missing.
+    map<string, NodePrepareResourceResponse> claims = 1;
+}
+
+message NodePrepareResourceResponse {
+    // These are the additional devices that kubelet must
+    // make available via the container runtime. A resource
+    // may have zero or more devices.
+    repeated string cdi_devices = 1 [(gogoproto.customname) = "CDIDevices"];
+    // If non-empty, preparing the ResourceClaim failed.
+    // cdi_devices is ignored in that case.
+    string error = 2;
+}
+
+message NodeUnprepareResourcesRequest {
+    // The list of ResourceClaims that are to be unprepared.
+    repeated Claim claims = 1;
+}
+
+message NodeUnprepareResourcesResponse {
+    // The ResourceClaims for which preparation was reverted.
+    // The same rules as for NodePrepareResourcesResponse.claims
+    // apply.
+    map<string, NodeUnprepareResourceResponse> claims = 1;
+}
+
+message NodeUnprepareResourceResponse {
+    // If non-empty, unpreparing the ResourceClaim failed.
+    string error = 1;
+}
+
+message Claim {
+    // The ResourceClaim namespace (ResourceClaim.meta.Namespace).
+    // This field is REQUIRED.
+    string namespace = 1;
+    // The UID of the Resource claim (ResourceClaim.meta.UUID).
+    // This field is REQUIRED.
+    string uid = 2;
+    // The name of the Resource claim (ResourceClaim.meta.Name)
+    // This field is REQUIRED.
+    string name = 3;
+    // Resource handle (AllocationResult.ResourceHandles[*].Data)
+    // This field is REQUIRED.
+    string resource_handle = 4;
+}