kubelet: support structured parameters for preparing resources

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.

Kubernetes-commit: 6f1ddfcd2e36c76b4e28dbb0ea355441cc4caeb2

pkg/apis/dra/v1alpha2/api.proto

@@ -22,6 +22,7 @@ package v1alpha2;
 option go_package = "k8s.io/kubelet/pkg/apis/dra/v1alpha2";
 
 import "github.com/gogo/protobuf/gogoproto/gogo.proto";
+import "k8s.io/api/resource/v1alpha2/generated.proto";
 
 option (gogoproto.goproto_stringer_all) = false;
 option (gogoproto.stringer_all) =  true;
@@ -52,6 +53,12 @@ message NodePrepareResourceRequest {
     // Resource handle (AllocationResult.ResourceHandles[*].Data)
     // This field is REQUIRED.
     string resource_handle = 4;
+    // Structured parameter resource handle (AllocationResult.ResourceHandles[*].StructuredData).
+    // This field is OPTIONAL. If present, it needs to be used
+    // instead of resource_handle. It will only have a single entry.
+    //
+    // Using "repeated" instead of "optional" is a workaround for https://github.com/gogo/protobuf/issues/713.
+    repeated k8s.io.api.resource.v1alpha2.StructuredResourceHandle structured_resource_handle = 5;
 }
 
 message NodePrepareResourceResponse {
@@ -74,6 +81,10 @@ message NodeUnprepareResourceRequest {
     // Resource handle (AllocationResult.ResourceHandles[*].Data)
     // This field is REQUIRED.
     string resource_handle = 4;
+    // Structured parameter resource handle (AllocationResult.ResourceHandles[*].StructuredData).
+    // This field is OPTIONAL. If present, it needs to be used
+    // instead of resource_handle. It will only have a single entry.
+    repeated k8s.io.api.resource.v1alpha2.StructuredResourceHandle structured_resource_handle = 5;
 }
 
 message NodeUnprepareResourceResponse {