Fixing Module CR deletion during node reboot

In case node it rebooted(for any reason) and the Module CR is being
deleted at the same period of time, the following sequence happens:
1) node becomes NotReady
2) module-nmc controller removes Spec from NMC
3) nmc controller does not schedule any unloader pod, since the node is
   not ready
4) node becomes ready
5) nmc controller does not schedule unloader pod, since after node
   reboot it ignores scheduling unloader pod, since the kernel module is
not loaded anyway
6) no unloader pod running, meaning Status in the NMC is not deleted,
   meaning Module CR cannot be finalized, since Status in NMC is present

Solution:
When nmc controller processes Modules without Spec, and the node has
been rebooted, the nmc controller will delete the Status from NMC.

Author: yevgeny-shnaidman

internal/controllers/nmc_reconciler.go

@@ -408,8 +408,10 @@ func (h *nmcReconcilerHelperImpl) ProcessUnconfiguredModuleStatus(
 	   it also fixes the scenario when node's kernel was upgraded, so unload pod will fail anyway
 	*/
 	if h.nodeAPI.NodeBecomeReadyAfter(node, status.LastTransitionTime) {
-		logger.Info("node was rebooted, no need to unload kernel module that is not present in kernel, will wait until NMC spec is updated")
-		return nil
+		logger.Info("node was rebooted and spec is missing: delete the status to allow Module CR unload, if needed")
+		patchFrom := client.MergeFrom(nmcObj.DeepCopy())
+		nmc.RemoveModuleStatus(&nmcObj.Status.Modules, status.Namespace, status.Name)
+		return h.client.Status().Patch(ctx, nmcObj, patchFrom)
 	}
 
 	pod, err := h.pm.GetWorkerPod(ctx, podName, status.Namespace)

internal/controllers/nmc_reconciler_test.go

@@ -793,6 +793,8 @@ var _ = Describe("nmcReconcilerHelperImpl_ProcessUnconfiguredModuleStatus", func
 		podName = workerPodName(nmcName, name)
 
 		client *testclient.MockClient
+		sw     *testclient.MockStatusWriter
+
 		pm     *MockpodManager
 		nm     *node.MockNode
 		helper nmcReconcilerHelper
@@ -801,6 +803,7 @@ var _ = Describe("nmcReconcilerHelperImpl_ProcessUnconfiguredModuleStatus", func
 	BeforeEach(func() {
 		ctrl := gomock.NewController(GinkgoT())
 		client = testclient.NewMockClient(ctrl)
+		sw = testclient.NewMockStatusWriter(ctrl)
 		pm = NewMockpodManager(ctrl)
 		nm = node.NewMockNode(ctrl)
 		helper = newNMCReconcilerHelper(client, pm, nil, nm)
@@ -820,7 +823,11 @@ var _ = Describe("nmcReconcilerHelperImpl_ProcessUnconfiguredModuleStatus", func
 	node := v1.Node{}
 
 	It("should do nothing , if the node has been rebooted/ready lately", func() {
-		nm.EXPECT().NodeBecomeReadyAfter(&node, status.LastTransitionTime).Return(true)
+		gomock.InOrder(
+			nm.EXPECT().NodeBecomeReadyAfter(&node, status.LastTransitionTime).Return(true),
+			client.EXPECT().Status().Return(sw),
+			sw.EXPECT().Patch(ctx, nmc, gomock.Any()),
+		)
 
 		Expect(
 			helper.ProcessUnconfiguredModuleStatus(ctx, nmc, status, &node),