refactor: remove multiple pods sharing one claim in prepareResourceClaim

In the scenario of single device shared by multiple pods, the pods will
not share the same ResourceClaim. We process the ResourceClaim for each
single pod.

Author: ngcxy

pkg/driver/dra_hooks.go

@@ -144,20 +144,21 @@ func (np *NetworkDriver) prepareResourceClaim(ctx context.Context, claim *resour
 	defer func() {
 		klog.V(2).Infof("PrepareResourceClaim Claim %s/%s  took %v", claim.Namespace, claim.Name, time.Since(start))
 	}()
-	// TODO: shared devices may allocate the same device to multiple pods, i.e. macvlan, ipvlan, ...
-	podUIDs := []types.UID{}
-	for _, reserved := range claim.Status.ReservedFor {
-		if reserved.Resource != "pods" || reserved.APIGroup != "" {
-			klog.Infof("Driver only supports Pods, unsupported reference %#v", reserved)
-			continue
-		}
-		podUIDs = append(podUIDs, reserved.UID)
-	}
-	if len(podUIDs) == 0 {
+	if len(claim.Status.ReservedFor) == 0 {
 		klog.Infof("no pods allocated to claim %s/%s", claim.Namespace, claim.Name)
 		return kubeletplugin.PrepareResult{}
 	}
 
+	// One ResourceClaim is consumed by a single pod, regardless of whether the device is allocated in
+	// exclusive or shared (e.g., ipvlan, macvlan) way, so we process the first and only consumer in ReservedFor.
+	reserved := claim.Status.ReservedFor[0]
+	if reserved.Resource != "pods" || reserved.APIGroup != "" {
+		return kubeletplugin.PrepareResult{
+			Err: fmt.Errorf("driver only supports Pods, unsupported reference %#v", reserved),
+		}
+	}
+	podUID := reserved.UID
+
 	nlHandle, err := nlwrap.NewHandle()
 	if err != nil {
 		return kubeletplugin.PrepareResult{
@@ -247,12 +248,10 @@ func (np *NetworkDriver) prepareResourceClaim(ctx context.Context, claim *resour
 				continue
 			}
 			deviceCfg.RDMADevice = buildRDMAConfig(rdmaDevName, charDevices)
-			for _, uid := range podUIDs {
-				if err := np.podConfigStore.SetDeviceConfig(uid, result.Device, deviceCfg); err != nil {
-					errorList = append(errorList, fmt.Errorf("failed to persist device config for pod %s device %s: %v", uid, result.Device, err))
-				}
+			if err := np.podConfigStore.SetDeviceConfig(podUID, result.Device, deviceCfg); err != nil {
+				errorList = append(errorList, fmt.Errorf("failed to persist device config for pod %s device %s: %v", podUID, result.Device, err))
 			}
-			klog.V(4).Infof("IB-only claim resources for pods %v : %#v", podUIDs, deviceCfg)
+			klog.V(4).Infof("IB-only claim resources for pod %s : %#v", podUID, deviceCfg)
 			continue
 		}
 
@@ -395,14 +394,10 @@ func (np *NetworkDriver) prepareResourceClaim(ctx context.Context, claim *resour
 			}
 		}
 
-		// TODO: support for multiple pods sharing the same device
-		// we'll create the subinterface here
-		for _, uid := range podUIDs {
-			if err := np.podConfigStore.SetDeviceConfig(uid, result.Device, deviceCfg); err != nil {
-				errorList = append(errorList, fmt.Errorf("failed to persist device config for pod %s device %s: %v", uid, result.Device, err))
-			}
+		if err := np.podConfigStore.SetDeviceConfig(podUID, result.Device, deviceCfg); err != nil {
+			errorList = append(errorList, fmt.Errorf("failed to persist device config for pod %s device %s: %v", podUID, result.Device, err))
 		}
-		klog.V(4).Infof("Claim Resources for pods %v : %#v", podUIDs, deviceCfg)
+		klog.V(4).Infof("Claim Resources for pod %s : %#v", podUID, deviceCfg)
 	}
 
 	if len(errorList) > 0 {