Addressed comments

pkg/apis/resource/types.go

@@ -403,7 +403,9 @@ type DeviceRequest struct {
 	// request.
 	//
 	// A class is required if no subrequests are specified in the
-	// firstAvailable list. Which classes are available depends on the cluster.
+	// firstAvailable list and no class can be set if subrequests
+	// are specified in the firstAvailable list.
+	// Which classes are available depends on the cluster.
 	//
 	// Administrators may use this to restrict which devices may get
 	// requested by only installing classes with selectors for permitted
@@ -420,6 +422,9 @@ type DeviceRequest struct {
 	// request. All selectors must be satisfied for a device to be
 	// considered.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// +optional
 	// +listType=atomic
 	Selectors []DeviceSelector
@@ -440,6 +445,9 @@ type DeviceRequest struct {
 	// the mode is ExactCount and count is not specified, the default count is
 	// one. Any other requests must specify this field.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// More modes may get added in the future. Clients must refuse to handle
 	// requests with unknown modes.
 	//
@@ -449,6 +457,9 @@ type DeviceRequest struct {
 	// Count is used only when the count mode is "ExactCount". Must be greater than zero.
 	// If AllocationMode is ExactCount and this field is not specified, the default is one.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// +optional
 	// +oneOf=AllocationMode
 	Count int64
@@ -459,6 +470,9 @@ type DeviceRequest struct {
 	// all ordinary claims to the device with respect to access modes and
 	// any resource allocations.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// This is an alpha field and requires enabling the DRAAdminAccess
 	// feature gate. Admin access is disabled if this field is unset or
 	// set to false, otherwise it is enabled.
@@ -467,9 +481,21 @@ type DeviceRequest struct {
 	// +featureGate=DRAAdminAccess
 	AdminAccess *bool
 
-	// FirstAvailable contains subrequests, exactly one of which must be satisfied
+	// FirstAvailable contains subrequests, of which exactly one will be
-	// in order to satisfy this request. This field may only be set in the
+	// satisfied by the scheduler to satisfy this request. It tries to
-	// entries of DeviceClaim.Requests.
+	// satisfy them in the order in which they are listed here. So if
+	// there are two entries in the list, the scheduler will only check
+	// the second one if it determines that the first one cannot be used.
+	//
+	// This field may only be set in the entries of DeviceClaim.Requests.
+	//
+	// DRA does not yet implement scoring, so the scheduler will
+	// select the first set of devices that satisfies all the
+	// requests in the claim. And if the requirements can
+	// be satisfied on more than one node, other scheduling features
+	// will determine which node is chosen. This means that the set of
+	// devices allocated to a claim might not be the optimal set
+	// available to the cluster. Scoring will be implemented later.
 	//
 	// +optional
 	// +oneOf=deviceRequestType

pkg/apis/resource/v1alpha3/defaults.go

@@ -26,7 +26,10 @@ func addDefaultingFuncs(scheme *runtime.Scheme) error {
 }
 
 func SetDefaults_DeviceRequest(obj *resourceapi.DeviceRequest) {
-	if len(obj.FirstAvailable) > 0 {
+	// If the deviceClassName is not set, then the request will have
+	// subrequests and the allocationMode and count fields should not
+	// be set.
+	if obj.DeviceClassName == "" {
 		return
 	}
 	if obj.AllocationMode == "" {

pkg/apis/resource/v1alpha3/defaults_test.go

@@ -34,7 +34,11 @@ func TestSetDefaultAllocationMode(t *testing.T) {
 	claim := &v1alpha3.ResourceClaim{
 		Spec: v1alpha3.ResourceClaimSpec{
 			Devices: v1alpha3.DeviceClaim{
-				Requests: []v1alpha3.DeviceRequest{{}},
+				Requests: []v1alpha3.DeviceRequest{
+					{
+						DeviceClassName: "device-class",
+					},
+				},
 			},
 		},
 	}

pkg/apis/resource/v1beta1/defaults.go

@@ -26,7 +26,10 @@ func addDefaultingFuncs(scheme *runtime.Scheme) error {
 }
 
 func SetDefaults_DeviceRequest(obj *resourceapi.DeviceRequest) {
-	if len(obj.FirstAvailable) > 0 {
+	// If the deviceClassName is not set, then the request will have
+	// subrequests and the allocationMode and count fields should not
+	// be set.
+	if obj.DeviceClassName == "" {
 		return
 	}
 	if obj.AllocationMode == "" {

pkg/apis/resource/v1beta1/defaults_test.go

@@ -34,7 +34,11 @@ func TestSetDefaultAllocationMode(t *testing.T) {
 	claim := &v1beta1.ResourceClaim{
 		Spec: v1beta1.ResourceClaimSpec{
 			Devices: v1beta1.DeviceClaim{
-				Requests: []v1beta1.DeviceRequest{{}},
+				Requests: []v1beta1.DeviceRequest{
+					{
+						DeviceClassName: "device-class",
+					},
+				},
 			},
 		},
 	}

pkg/apis/resource/validation/validation.go

@@ -169,10 +169,16 @@ func gatherAllocatedDevices(allocationResult *resource.DeviceAllocationResult) s
 
 func validateDeviceRequest(request resource.DeviceRequest, fldPath *field.Path, stored bool) field.ErrorList {
 	allErrs := validateRequestName(request.Name, fldPath.Child("name"))
-	if len(request.FirstAvailable) > 0 {
+
-		if request.DeviceClassName != "" {
+	if request.DeviceClassName == "" && len(request.FirstAvailable) == 0 {
-			allErrs = append(allErrs, field.Invalid(fldPath.Child("deviceClassName"), request.DeviceClassName, "must not be specified when firstAvailable is set"))
+		allErrs = append(allErrs, field.Required(fldPath, "exactly one of `deviceClassName` or `firstAvailable` must be specified"))
-		}
+	} else if request.DeviceClassName != "" && len(request.FirstAvailable) > 0 {
+		allErrs = append(allErrs, field.Invalid(fldPath, nil, "exactly one of `deviceClassName` or `firstAvailable` must be specified"))
+	} else if request.DeviceClassName != "" {
+		allErrs = append(allErrs, validateDeviceClass(request.DeviceClassName, fldPath.Child("deviceClassName"))...)
+		allErrs = append(allErrs, validateSelectorSlice(request.Selectors, fldPath.Child("selectors"), stored)...)
+		allErrs = append(allErrs, validateDeviceAllocationMode(request.AllocationMode, request.Count, fldPath.Child("allocationMode"), fldPath.Child("count"))...)
+	} else if len(request.FirstAvailable) > 0 {
 		if request.Selectors != nil {
 			allErrs = append(allErrs, field.Invalid(fldPath.Child("selectors"), request.Selectors, "must not be specified when firstAvailable is set"))
 		}
@@ -193,11 +199,7 @@ func validateDeviceRequest(request resource.DeviceRequest, fldPath *field.Path,
 				return subRequest.Name, "name"
 			},
 			fldPath.Child("firstAvailable"))...)
-		return allErrs
 	}
-	allErrs = append(allErrs, validateDeviceClass(request.DeviceClassName, fldPath.Child("deviceClassName"))...)
-	allErrs = append(allErrs, validateSelectorSlice(request.Selectors, fldPath.Child("selectors"), stored)...)
-	allErrs = append(allErrs, validateDeviceAllocationMode(request.AllocationMode, request.Count, fldPath.Child("allocationMode"), fldPath.Child("count"))...)
 	return allErrs
 }
 

pkg/apis/resource/validation/validation_resourceclaim_test.go

@@ -245,8 +245,8 @@ func TestValidateClaim(t *testing.T) {
 				return claim
 			}(),
 		},
-		"missing-classname": {
+		"missing-classname-and-firstavailable": {
-			wantFailures: field.ErrorList{field.Required(field.NewPath("spec", "devices", "requests").Index(0).Child("deviceClassName"), "")},
+			wantFailures: field.ErrorList{field.Required(field.NewPath("spec", "devices", "requests").Index(0), "exactly one of `deviceClassName` or `firstAvailable` must be specified")},
 			claim: func() *resource.ResourceClaim {
 				claim := testClaim(goodName, goodNS, validClaimSpec)
 				claim.Spec.Devices.Requests[0].DeviceClassName = ""
@@ -578,11 +578,7 @@ func TestValidateClaim(t *testing.T) {
 		},
 		"prioritized-list-field-on-parent": {
 			wantFailures: field.ErrorList{
-				field.Invalid(field.NewPath("spec", "devices", "requests").Index(0).Child("deviceClassName"), goodName, "must not be specified when firstAvailable is set"),
+				field.Invalid(field.NewPath("spec", "devices", "requests").Index(0), nil, "exactly one of `deviceClassName` or `firstAvailable` must be specified"),
-				field.Invalid(field.NewPath("spec", "devices", "requests").Index(0).Child("selectors"), validSelector, "must not be specified when firstAvailable is set"),
-				field.Invalid(field.NewPath("spec", "devices", "requests").Index(0).Child("allocationMode"), resource.DeviceAllocationModeAll, "must not be specified when firstAvailable is set"),
-				field.Invalid(field.NewPath("spec", "devices", "requests").Index(0).Child("count"), int64(2), "must not be specified when firstAvailable is set"),
-				field.Invalid(field.NewPath("spec", "devices", "requests").Index(0).Child("adminAccess"), ptr.To(true), "must not be specified when firstAvailable is set"),
 			},
 			claim: func() *resource.ResourceClaim {
 				claim := testClaim(goodName, goodNS, validClaimSpecWithFirstAvailable)

pkg/apis/resource/validation/validation_resourceclaimtemplate_test.go

@@ -190,7 +190,7 @@ func TestValidateClaimTemplate(t *testing.T) {
 			template:     testClaimTemplate(goodName, goodNS, validClaimSpecWithFirstAvailable),
 		},
 		"proritized-list-class-name-on-parent": {
-			wantFailures: field.ErrorList{field.Invalid(field.NewPath("spec", "spec", "devices", "requests").Index(0).Child("deviceClassName"), goodName, "must not be specified when firstAvailable is set")},
+			wantFailures: field.ErrorList{field.Invalid(field.NewPath("spec", "spec", "devices", "requests").Index(0), nil, "exactly one of `deviceClassName` or `firstAvailable` must be specified")},
 			template: func() *resource.ResourceClaimTemplate {
 				template := testClaimTemplate(goodName, goodNS, validClaimSpecWithFirstAvailable)
 				template.Spec.Spec.Devices.Requests[0].DeviceClassName = goodName

staging/src/k8s.io/api/resource/v1alpha3/types.go

@@ -400,7 +400,9 @@ type DeviceRequest struct {
 	// request.
 	//
 	// A class is required if no subrequests are specified in the
-	// firstAvailable list. Which classes are available depends on the cluster.
+	// firstAvailable list and no class can be set if subrequests
+	// are specified in the firstAvailable list.
+	// Which classes are available depends on the cluster.
 	//
 	// Administrators may use this to restrict which devices may get
 	// requested by only installing classes with selectors for permitted
@@ -417,6 +419,9 @@ type DeviceRequest struct {
 	// request. All selectors must be satisfied for a device to be
 	// considered.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// +optional
 	// +listType=atomic
 	Selectors []DeviceSelector `json:"selectors,omitempty" protobuf:"bytes,3,name=selectors"`
@@ -437,6 +442,9 @@ type DeviceRequest struct {
 	// the mode is ExactCount and count is not specified, the default count is
 	// one. Any other requests must specify this field.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// More modes may get added in the future. Clients must refuse to handle
 	// requests with unknown modes.
 	//
@@ -446,6 +454,9 @@ type DeviceRequest struct {
 	// Count is used only when the count mode is "ExactCount". Must be greater than zero.
 	// If AllocationMode is ExactCount and this field is not specified, the default is one.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// +optional
 	// +oneOf=AllocationMode
 	Count int64 `json:"count,omitempty" protobuf:"bytes,5,opt,name=count"`
@@ -456,6 +467,9 @@ type DeviceRequest struct {
 	// all ordinary claims to the device with respect to access modes and
 	// any resource allocations.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// This is an alpha field and requires enabling the DRAAdminAccess
 	// feature gate. Admin access is disabled if this field is unset or
 	// set to false, otherwise it is enabled.
@@ -467,8 +481,8 @@ type DeviceRequest struct {
 	// FirstAvailable contains subrequests, of which exactly one will be
 	// satisfied by the scheduler to satisfy this request. It tries to
 	// satisfy them in the order in which they are listed here. So if
-	// there are two entries in the list, the schduler will only check
+	// there are two entries in the list, the scheduler will only check
-	// the second one if it determines that the first one can not be used.
+	// the second one if it determines that the first one cannot be used.
 	//
 	// This field may only be set in the entries of DeviceClaim.Requests.
 	//

staging/src/k8s.io/api/resource/v1beta1/types.go

@@ -409,7 +409,9 @@ type DeviceRequest struct {
 	// request.
 	//
 	// A class is required if no subrequests are specified in the
-	// firstAvailable list. Which classes are available depends on the cluster.
+	// firstAvailable list and no class can be set if subrequests
+	// are specified in the firstAvailable list.
+	// Which classes are available depends on the cluster.
 	//
 	// Administrators may use this to restrict which devices may get
 	// requested by only installing classes with selectors for permitted
@@ -426,6 +428,9 @@ type DeviceRequest struct {
 	// request. All selectors must be satisfied for a device to be
 	// considered.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// +optional
 	// +listType=atomic
 	Selectors []DeviceSelector `json:"selectors,omitempty" protobuf:"bytes,3,name=selectors"`
@@ -446,6 +451,9 @@ type DeviceRequest struct {
 	// the mode is ExactCount and count is not specified, the default count is
 	// one. Any other requests must specify this field.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// More modes may get added in the future. Clients must refuse to handle
 	// requests with unknown modes.
 	//
@@ -455,6 +463,9 @@ type DeviceRequest struct {
 	// Count is used only when the count mode is "ExactCount". Must be greater than zero.
 	// If AllocationMode is ExactCount and this field is not specified, the default is one.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// +optional
 	// +oneOf=AllocationMode
 	Count int64 `json:"count,omitempty" protobuf:"bytes,5,opt,name=count"`
@@ -465,6 +476,9 @@ type DeviceRequest struct {
 	// all ordinary claims to the device with respect to access modes and
 	// any resource allocations.
 	//
+	// This field can only be set when deviceClassName is set and no subrequests
+	// are specified in the firstAvailable list.
+	//
 	// This is an alpha field and requires enabling the DRAAdminAccess
 	// feature gate. Admin access is disabled if this field is unset or
 	// set to false, otherwise it is enabled.
@@ -476,8 +490,8 @@ type DeviceRequest struct {
 	// FirstAvailable contains subrequests, of which exactly one will be
 	// satisfied by the scheduler to satisfy this request. It tries to
 	// satisfy them in the order in which they are listed here. So if
-	// there are two entries in the list, the schduler will only check
+	// there are two entries in the list, the scheduler will only check
-	// the second one if it determines that the first one can not be used.
+	// the second one if it determines that the first one cannot be used.
 	//
 	// This field may only be set in the entries of DeviceClaim.Requests.
 	//