DRA E2E: support usage without real nodes

This enables usage in test/integration/dra:
- "deploying" a driver merely sets up the usual slices and class
- created pods get force-deleted

test/e2e/dra/utils/builder.go

@@ -517,7 +517,12 @@ func (b *Builder) tearDown(tCtx ktesting.TContext) {
 			continue
 		}
 		tCtx.Logf("Deleting %T %s", &pod, klog.KObj(&pod))
-		err := tCtx.Client().CoreV1().Pods(b.namespace).Delete(tCtx, pod.Name, metav1.DeleteOptions{})
+		options := metav1.DeleteOptions{}
+		if !b.driver.WithRealNodes {
+			// Force-delete, no kubelet.
+			options.GracePeriodSeconds = ptr.To(int64(0))
+		}
+		err := tCtx.Client().CoreV1().Pods(b.namespace).Delete(tCtx, pod.Name, options)
 		if !apierrors.IsNotFound(err) {
 			tCtx.ExpectNoError(err, "delete pod")
 		}

test/e2e/dra/utils/deploy.go

@@ -311,6 +311,7 @@ func NewDriverInstance(tCtx ktesting.TContext) *Driver {
 		// By default, assume that the kubelet supports DRA and that
 		// the driver's removal causes ResourceSlice cleanup.
 		WithKubelet:                true,
+		WithRealNodes:              true,
 		ExpectResourceSliceRemoval: true,
 	}
 	if tCtx != nil {
@@ -385,6 +386,9 @@ type Driver struct {
 	// Register the DRA test driver with the kubelet and expect DRA to work (= feature.DynamicResourceAllocation).
 	WithKubelet bool
 
+	// Run driver pods. If false, only set up slices and class.
+	WithRealNodes bool
+
 	mutex      sync.Mutex
 	fail       map[MethodInstance]bool
 	callCounts map[MethodInstance]int64
@@ -456,6 +460,13 @@ func (d *Driver) SetUp(tCtx ktesting.TContext, kubeletRootDir string, nodes *Nod
 		}
 	}
 
+	if !d.WithRealNodes {
+		// Slices have been created as usual.
+		// We don't actually have nodes, so
+		// running pods wouldn't work and can be skipped.
+		return
+	}
+
 	// Create service account and corresponding RBAC rules.
 	d.serviceAccountName = "dra-kubelet-plugin-" + d.Name + d.InstanceSuffix + "-service-account"
 	content := example.PluginPermissions