WIP: Implement DRA support in Cluster Autoscaler

cluster-autoscaler/dynamicresources/listers.go

@@ -0,0 +1,70 @@
+/*
+Copyright 2024 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.
+*/
+
+package dynamicresources
+
+import (
+	resourceapi "k8s.io/api/resource/v1alpha3"
+	"k8s.io/apimachinery/pkg/labels"
+	resourceapilisters "k8s.io/client-go/listers/resource/v1alpha3"
+)
+
+// These listers are introduced for Provider dependency injection.
+
+// providerClaimLister is a subset of ResourceClaimLister needed by the Provider.
+type providerClaimLister interface {
+	List() ([]*resourceapi.ResourceClaim, error)
+}
+
+// providerClaimLister is a subset of ResourceSliceLister needed by the Provider.
+type providerSliceLister interface {
+	List() ([]*resourceapi.ResourceSlice, error)
+}
+
+// providerClassLister is a subset of DeviceClassLister needed by the Provider.
+type providerClassLister interface {
+	List() ([]*resourceapi.DeviceClass, error)
+}
+
+// resourceClaimApiLister implements providerClaimLister using a real ResourceClaimLister listing from the API.
+type resourceClaimApiLister struct {
+	apiLister resourceapilisters.ResourceClaimLister
+}
+
+// List lists all ResourceClaims.
+func (l *resourceClaimApiLister) List() ([]*resourceapi.ResourceClaim, error) {
+	return l.apiLister.List(labels.Everything())
+}
+
+// resourceSliceApiLister implements providerSliceLister using a real ResourceSliceLister listing from the API.
+type resourceSliceApiLister struct {
+	apiLister resourceapilisters.ResourceSliceLister
+}
+
+// List lists all ResourceSlices.
+func (l *resourceSliceApiLister) List() (ret []*resourceapi.ResourceSlice, err error) {
+	return l.apiLister.List(labels.Everything())
+}
+
+// deviceClassApiLister implements providerClassLister using a real DeviceClassLister listing from the API.
+type deviceClassApiLister struct {
+	apiLister resourceapilisters.DeviceClassLister
+}
+
+// List lists all DeviceClasses.
+func (l *deviceClassApiLister) List() (ret []*resourceapi.DeviceClass, err error) {
+	return l.apiLister.List(labels.Everything())
+}

cluster-autoscaler/dynamicresources/provider.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2024 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.
+*/
+
+package dynamicresources
+
+import (
+	resourceapi "k8s.io/api/resource/v1alpha3"
+	"k8s.io/client-go/informers"
+)
+
+// Provider provides DRA-related objects.
+type Provider struct {
+	resourceClaims providerClaimLister
+	resourceSlices providerSliceLister
+	deviceClasses  providerClassLister
+}
+
+// NewProviderFromInformers returns a new Provider which uses InformerFactory listers to list the DRA resources.
+func NewProviderFromInformers(informerFactory informers.SharedInformerFactory) *Provider {
+	claims := &resourceClaimApiLister{apiLister: informerFactory.Resource().V1alpha3().ResourceClaims().Lister()}
+	slices := &resourceSliceApiLister{apiLister: informerFactory.Resource().V1alpha3().ResourceSlices().Lister()}
+	devices := &deviceClassApiLister{apiLister: informerFactory.Resource().V1alpha3().DeviceClasses().Lister()}
+	return NewProvider(claims, slices, devices)
+}
+
+// NewProvider returns a new Provider which uses the provided listers to list the DRA resources.
+func NewProvider(claims providerClaimLister, slices providerSliceLister, classes providerClassLister) *Provider {
+	return &Provider{
+		resourceClaims: claims,
+		resourceSlices: slices,
+		deviceClasses:  classes,
+	}
+}
+
+// Snapshot returns a snapshot of all DRA resources at a ~single point in time.
+func (p *Provider) Snapshot() (Snapshot, error) {
+	claims, err := p.resourceClaims.List()
+	if err != nil {
+		return Snapshot{}, err
+	}
+	claimMap := make(map[resourceClaimRef]*resourceapi.ResourceClaim)
+	for _, claim := range claims {
+		claimMap[resourceClaimRef{Name: claim.Name, Namespace: claim.Namespace}] = claim
+	}
+
+	slices, err := p.resourceSlices.List()
+
+	if err != nil {
+		return Snapshot{}, err
+	}
+	slicesMap := make(map[string][]*resourceapi.ResourceSlice)
+	var nonNodeLocalSlices []*resourceapi.ResourceSlice
+	for _, slice := range slices {
+		if slice.Spec.NodeName == "" {
+			nonNodeLocalSlices = append(nonNodeLocalSlices, slice)
+		} else {
+			slicesMap[slice.Spec.NodeName] = append(slicesMap[slice.Spec.NodeName], slice)
+		}
+	}
+
+	classes, err := p.deviceClasses.List()
+	if err != nil {
+		return Snapshot{}, err
+	}
+	classMap := make(map[string]*resourceapi.DeviceClass)
+	for _, class := range classes {
+		classMap[class.Name] = class
+	}
+
+	return Snapshot{
+		resourceClaimsByRef:        claimMap,
+		resourceSlicesByNodeName:   slicesMap,
+		nonNodeLocalResourceSlices: nonNodeLocalSlices,
+		deviceClasses:              classMap,
+	}, nil
+}

cluster-autoscaler/dynamicresources/provider_test.go

@@ -0,0 +1,23 @@
+/*
+Copyright 2024 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.
+*/
+
+package dynamicresources
+
+import "testing"
+
+func TestProviderSnapshot(t *testing.T) {
+	// TODO(DRA): Write.
+}

cluster-autoscaler/dynamicresources/resource_claim_utils.go

@@ -0,0 +1,123 @@
+/*
+Copyright 2024 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.
+*/
+
+package dynamicresources
+
+import (
+	"fmt"
+
+	apiv1 "k8s.io/api/core/v1"
+	resourceapi "k8s.io/api/resource/v1alpha3"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/utils/ptr"
+)
+
+// ClaimOwningPod returns the name and UID of the Pod owner of the provided claim. If the claim isn't
+// owned by a Pod, empty strings are returned.
+func ClaimOwningPod(claim *resourceapi.ResourceClaim) (string, types.UID) {
+	for _, owner := range claim.OwnerReferences {
+		if ptr.Deref(owner.Controller, false) &&
+			owner.APIVersion == "v1" &&
+			owner.Kind == "Pod" {
+			return owner.Name, owner.UID
+		}
+	}
+	return "", ""
+}
+
+// ClaimAllocated returns whether the provided claim is allocated.
+func ClaimAllocated(claim *resourceapi.ResourceClaim) bool {
+	return claim.Status.Allocation != nil
+}
+
+// ClaimInUse returns whether the provided claim is currently reserved for any consumer.
+func ClaimInUse(claim *resourceapi.ResourceClaim) bool {
+	return len(claim.Status.ReservedFor) > 0
+}
+
+// ClaimReservedForPod returns whether the provided claim is currently reserved for the provided Pod.
+func ClaimReservedForPod(claim *resourceapi.ResourceClaim, pod *apiv1.Pod) bool {
+	for _, consumerRef := range claim.Status.ReservedFor {
+		if claimConsumerReferenceMatchesPod(pod, consumerRef) {
+			return true
+		}
+	}
+	return false
+}
+
+// DeallocateClaimInPlace clears the allocation of the provided claim.
+func DeallocateClaimInPlace(claim *resourceapi.ResourceClaim) {
+	claim.Status.Allocation = nil
+}
+
+// ClearPodReservationInPlace clears the reservation for the provided pod in the provided Claim. It is a no-op
+// if the claim isn't reserved for the Pod.
+func ClearPodReservationInPlace(claim *resourceapi.ResourceClaim, pod *apiv1.Pod) {
+	newReservedFor := make([]resourceapi.ResourceClaimConsumerReference, 0, len(claim.Status.ReservedFor))
+	for _, consumerRef := range claim.Status.ReservedFor {
+		if claimConsumerReferenceMatchesPod(pod, consumerRef) {
+			continue
+		}
+		newReservedFor = append(newReservedFor, consumerRef)
+	}
+	claim.Status.ReservedFor = newReservedFor
+}
+
+// AddPodReservationIfNeededInPlace adds a reservation for the provided pod to the provided Claim. It is a no-op
+// if the claim is already reserved for the Pod. Error is returned if the claim already has the maximum number of
+// reservations.
+func AddPodReservationIfNeededInPlace(claim *resourceapi.ResourceClaim, pod *apiv1.Pod) error {
+	alreadyReservedForPod := false
+	for _, consumerRef := range claim.Status.ReservedFor {
+		if claimConsumerReferenceMatchesPod(pod, consumerRef) {
+			alreadyReservedForPod = true
+			break
+		}
+	}
+	if !alreadyReservedForPod {
+		if len(claim.Status.ReservedFor) >= resourceapi.ResourceClaimReservedForMaxSize {
+			return fmt.Errorf("claim already reserved for %d consumers, can't add more", len(claim.Status.ReservedFor))
+		}
+		claim.Status.ReservedFor = append(claim.Status.ReservedFor, podClaimConsumerReference(pod))
+	}
+	return nil
+}
+
+func claimConsumerReferenceMatchesPod(pod *apiv1.Pod, ref resourceapi.ResourceClaimConsumerReference) bool {
+	return ref.APIGroup == "" && ref.Resource == "pods" && ref.Name == pod.Name && ref.UID == pod.UID
+}
+
+func podClaimConsumerReference(pod *apiv1.Pod) resourceapi.ResourceClaimConsumerReference {
+	return resourceapi.ResourceClaimConsumerReference{
+		Name:     pod.Name,
+		UID:      pod.UID,
+		Resource: "pods",
+		APIGroup: "",
+	}
+}
+
+func podClaimOwnerReference(pod *apiv1.Pod) metav1.OwnerReference {
+	truePtr := true
+	return metav1.OwnerReference{
+		APIVersion:         "v1",
+		Kind:               "Pod",
+		Name:               pod.Name,
+		UID:                pod.UID,
+		BlockOwnerDeletion: &truePtr,
+		Controller:         &truePtr,
+	}
+}

cluster-autoscaler/dynamicresources/resource_claim_utils_test.go

@@ -0,0 +1,19 @@
+/*
+Copyright 2024 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.
+*/
+
+package dynamicresources
+
+// TODO(DRA): Write util tests.