Add DRA support for GPU pod eviction during driver upgrades

[karthikvetrivel]

Description

Extends the driver-upgrade controller to detect and evict GPU workloads using Dynamic Resource Allocation (DRA) in addition to traditional nvidia.com/gpu resources. This ensures GPU driver upgrades work correctly as Kubernetes transitions from device plugins to the DRA model (GA in K8s 1.34+).

Changes

• internal/kubernetes/claim_cache.go (new): Implements ResourceClaimCache that watches ResourceClaim objects and maintains a map of pod UIDs with allocated NVIDIA GPU claims. Uses informers with O(1) pod UID lookups.

• internal/kubernetes/client.go:

  • Adds claimCache to the Client struct
  • Updates podUsesGPU() to check both traditional resources AND DRA ResourceClaims
  • Cache is started on client creation and synced before any operations

Testing

Tested in a kubeadm cluster (K8s 1.34) with NVIDIA DRA driver installed:

1. Created test workloads:

   • DRA GPU pod with allocated ResourceClaim (driver: gpu.nvidia.com)

2. Verified ResourceClaim allocation:

   $ kubectl get resourceclaim -n default dra-gpu-claim -o yaml
   status:
     allocation:
       devices:
         results:
         - driver: gpu.nvidia.com
           device: gpu-0
           pool: ipp1-0744
     reservedFor:
     - name: dra-allocated-pod
       resource: pods

3. Verified ResourceClaim cache synced:

   level=info msg=ResourceClaim cache synced successfully
   

4. Triggered driver upgrade eviction:

   level=info msg=Identifying GPU pods to delete
   level=info msg=GPU pod - default/dra-allocated-pod
   level=info msg=Deleting GPU pods...
   evicting pod default/dra-allocated-pod
   

5. Verified DRA pod evicted successfully:

   $ kubectl get pods -n default
   NAME                  READY   STATUS    RESTARTS   AGE

[shivamerla]

LGTM

[rahulait]

I'm wondering if we should evict ANY pod with a ResourceClaim requesting nvidia.com GPUs (regardless of allocation status) to prevent race conditions where a pending claim gets allocated during the upgrade - thoughts?

Don't we cordon the node before starting the upgrade? If the node is cordoned, then there won't be new allocations to that node.

[karthikvetrivel]

I'm wondering if we should evict ANY pod with a ResourceClaim requesting nvidia.com GPUs (regardless of allocation status) to prevent race conditions where a pending claim gets allocated during the upgrade - thoughts?

Don't we cordon the node before starting the upgrade? If the node is cordoned, then there won't be new allocations to that node.

I think you're right here. Good point, thanks for bringing it up.

[cdesiniotis]

I didn't review in great detail, but this looks reasonable to me. A couple of things to consider:

1. Do we want to merge this change (and get it included into a k8s-driver-manager / gpu-operator release) before the DRA driver is integrated with the gpu-operator? I believe the answer is yes since in many cases users will install the DRA driver alongside the GPU Operator (until they are integrated). @shivamerla do you have any contradicting opinions on this?
2. We will need to make a similar change in the gpu-operator itself. By default, the driver-upgrade state machine (and therefore the GPU pod evictions) are handled by our driver upgrade controller that runs in the gpu-operator. We will need to update this line https://github.com/NVIDIA/gpu-operator/blob/51dd7a28cd86fedde8c4daad65c2643582fa4615/cmd/gpu-operator/main.go#L176 to pass in a modified gpu pod filter (that accounts for pods requesting GPUs via DRA) when constructing the driver upgrade controller.

[karthikvetrivel]

I didn't review in great detail, but this looks reasonable to me. A couple of things to consider:

1. Do we want to merge this change (and get it included into a k8s-driver-manager / gpu-operator release) before the DRA driver is integrated with the gpu-operator? I believe the answer is yes since in many cases users will install the DRA driver alongside the GPU Operator (until they are integrated). @shivamerla do you have any contradicting opinions on this?
2. We will need to make a similar change in the gpu-operator itself. By default, the driver-upgrade state machine (and therefore the GPU pod evictions) are handled by our driver upgrade controller that runs in the gpu-operator. We will need to update this line https://github.com/NVIDIA/gpu-operator/blob/51dd7a28cd86fedde8c4daad65c2643582fa4615/cmd/gpu-operator/main.go#L176 to pass in a modified gpu pod filter (that accounts for pods requesting GPUs via DRA) when constructing the driver upgrade controller.

@cdesiniotis

1. Yes, I believe we should for the reasons you mentioned.

2. Good point--yeah, I see the same gpuPodSpecFilter in gpu-operator. Once we get this PR approved, I'll open another to make the same changes in that repo.

[tariq1890]

I don't understand why we are not consuming the error returned by wait.PollUntilContextTimeout here?

[karthikvetrivel]

You're right, we should. The error handling here became a bit convoluted through the refactors. I will update this once we decide how to search and clean up the claims (claims --> pods vs. pods --> claims).

[guptaNswati]

Though there is not much detail on best practice of how to clean up claims managed by DRA driver other than this two liner . But what Kevin was saying in the meeting make sense in terms of iterating on all gpu.nvidia.com claims and identifying pods referencing them and evicting them primarily because a claim can exist beyond the lifetime of a Pod and can be shared among multiple pods.

I was curious to look into it from extended resources perspective.

[ssalagam]

@karthikvetrivel , are we considering this for the next release?

[karthikvetrivel]

@karthikvetrivel , are we considering this for the next release?

For now, let's keep this PR around. It may be a part of our initiative to incorporate DRA into the operator. Thanks for taking a look.