CA: DRA integration MVP

cluster-autoscaler/simulator/dynamicresources/utils/resource_claims.go

@@ -0,0 +1,134 @@
+/*
+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 utils
+
+import (
+	apiv1 "k8s.io/api/core/v1"
+	resourceapi "k8s.io/api/resource/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/component-helpers/scheduling/corev1"
+	"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
+}
+
+// ClaimFullyReserved returns whether the provided claim already has the maximum possible reservations
+// set, and no more can be added.
+func ClaimFullyReserved(claim *resourceapi.ResourceClaim) bool {
+	return len(claim.Status.ReservedFor) >= resourceapi.ResourceClaimReservedForMaxSize
+}
+
+// ClaimAvailableOnNode returns whether the provided claim is allocated and available on the provided Node.
+func ClaimAvailableOnNode(claim *resourceapi.ResourceClaim, node *apiv1.Node) (bool, error) {
+	if !ClaimAllocated(claim) {
+		// Not allocated so not available anywhere.
+		return false, nil
+	}
+	selector := claim.Status.Allocation.NodeSelector
+	if selector == nil {
+		// nil means available everywhere.
+		return true, nil
+	}
+	return corev1.MatchNodeSelectorTerms(node, claim.Status.Allocation.NodeSelector)
+}
+
+// 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) {
+	if len(claim.Status.ReservedFor) == 0 {
+		return
+	}
+
+	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
+}
+
+// AddPodReservationInPlace 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.
+func AddPodReservationInPlace(claim *resourceapi.ResourceClaim, pod *apiv1.Pod) {
+	if !ClaimReservedForPod(claim, pod) {
+		claim.Status.ReservedFor = append(claim.Status.ReservedFor, PodClaimConsumerReference(pod))
+	}
+}
+
+// PodClaimConsumerReference returns a consumer reference entry for a ResourceClaim status ReservedFor field.
+func PodClaimConsumerReference(pod *apiv1.Pod) resourceapi.ResourceClaimConsumerReference {
+	return resourceapi.ResourceClaimConsumerReference{
+		Name:     pod.Name,
+		UID:      pod.UID,
+		Resource: "pods",
+		APIGroup: "",
+	}
+}
+
+// PodClaimOwnerReference returns an OwnerReference for a pod-owned ResourceClaim.
+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,
+	}
+}
+
+func claimConsumerReferenceMatchesPod(pod *apiv1.Pod, ref resourceapi.ResourceClaimConsumerReference) bool {
+	return ref.APIGroup == "" && ref.Resource == "pods" && ref.Name == pod.Name && ref.UID == pod.UID
+}