Allow providers to skip downward API resolving

node/nodeutil/controller.go

@@ -254,6 +254,11 @@ type NodeConfig struct {
 	// Set the error handler for node status update failures
 	NodeStatusUpdateErrorHandler node.ErrorHandler
 
+	// SkipDownwardAPIResolution can be used to skip any attempts at resolving downward API references
+	// in pods before calling CreatePod on the provider.
+	// Providers need this if they need to do their own custom resolving
+	SkipDownwardAPIResolution bool
+
 	routeAttacher func(Provider, NodeConfig, corev1listers.PodLister)
 }
 
@@ -400,6 +405,7 @@ func NewNode(name string, newProvider NewProviderFunc, opts ...NodeOpt) (*Node,
 		SecretInformer:            secretInformer,
 		ConfigMapInformer:         configMapInformer,
 		ServiceInformer:           serviceInformer,
+		SkipDownwardAPIResolution: cfg.SkipDownwardAPIResolution,
 	})
 	if err != nil {
 		return nil, errors.Wrap(err, "error creating pod controller")

node/pod.go

@@ -69,12 +69,14 @@ func (pc *PodController) createOrUpdatePod(ctx context.Context, pod *corev1.Pod)
 		"namespace": pod.GetNamespace(),
 	})
 
+	if !pc.skipDownwardAPIResolution {
 		// We do this so we don't mutate the pod from the informer cache
 		pod = pod.DeepCopy()
 		if err := podutils.PopulateEnvironmentVariables(ctx, pod, pc.resourceManager, pc.recorder); err != nil {
 			span.SetStatus(err)
 			return err
 		}
+	}
 
 	// We have to use a  different pod that we pass to the provider than the one that gets used in handleProviderError
 	// because the provider  may manipulate the pod in a separate goroutine while we were doing work

node/podcontroller.go

@@ -140,6 +140,11 @@ type PodController struct {
 	// This is used since `pc.Run()` is typically called in a goroutine and managing
 	// this can be non-trivial for callers.
 	err error
+
+	// skipDownwardAPIResolution can be used to skip any attempts at resolving downward API references
+	// in pods before calling CreatePod on the provider.
+	// Providers need this if they need to do their own custom resolving
+	skipDownwardAPIResolution bool
 }
 
 type knownPod struct {
@@ -196,6 +201,11 @@ type PodControllerConfig struct {
 	// For example, if the pod informer is not filtering based on pod.Spec.NodeName, you should
 	// set that filter here so the pod controller does not handle events for pods assigned to other nodes.
 	PodEventFilterFunc PodEventFilterFunc
+
+	// SkipDownwardAPIResolution can be used to skip any attempts at resolving downward API references
+	// in pods before calling CreatePod on the provider.
+	// Providers need this if they need to do their own custom resolving
+	SkipDownwardAPIResolution bool
 }
 
 // NewPodController creates a new pod controller with the provided config.
@@ -245,6 +255,7 @@ func NewPodController(cfg PodControllerConfig) (*PodController, error) {
 		done:                      make(chan struct{}),
 		recorder:                  cfg.EventRecorder,
 		podEventFilterFunc:        cfg.PodEventFilterFunc,
+		skipDownwardAPIResolution: cfg.SkipDownwardAPIResolution,
 	}
 
 	pc.syncPodsFromKubernetes = queue.New(cfg.SyncPodsFromKubernetesRateLimiter, "syncPodsFromKubernetes", pc.syncPodFromKubernetesHandler, cfg.SyncPodsFromKubernetesShouldRetryFunc)