controller/vm: add comprehensive unit tests for VM Controller

internal/controller/pod/pod_lcow.go

@@ -89,12 +89,17 @@ func (c *Controller) NewContainer(ctx context.Context, containerID string) (*lin
 		return nil, fmt.Errorf("container %q already exists in pod %q", containerID, c.podID)
 	}
 
+	scsiCtrl, err := c.vm.SCSIController(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("get SCSI controller for pod %s: %w", c.podID, err)
+	}
+
 	containerCtrl := linuxcontainer.New(
 		c.vm.RuntimeID(),
 		c.gcsPodID,
 		containerID,
 		c.vm.Guest(),
-		c.vm.SCSIController(),
+		scsiCtrl,
 		c.vm.Plan9Controller(),
 		c.vm.VPCIController(),
 	)

internal/controller/pod/pod_lcow_test.go

@@ -42,7 +42,7 @@ func newSetup(t *testing.T) (*mocks.MockvmController, *mocks.MocknetworkControll
 func expectVMCallsForNewContainer(vm *mocks.MockvmController) {
 	vm.EXPECT().RuntimeID().Return("vm-runtime-1")
 	vm.EXPECT().Guest().Return(nil)
-	vm.EXPECT().SCSIController().Return(nil)
+	vm.EXPECT().SCSIController(gomock.Any()).Return(nil, nil)
 	vm.EXPECT().Plan9Controller().Return(nil)
 	vm.EXPECT().VPCIController().Return(nil)
 }
@@ -191,6 +191,18 @@ func TestNewContainer(t *testing.T) {
 			}
 		}
 	})
+
+	t.Run("scsi controller error", func(t *testing.T) {
+		vm, _, c := newSetup(t)
+		vm.EXPECT().SCSIController(gomock.Any()).Return(nil, errTest)
+
+		if _, err := c.NewContainer(t.Context(), "container-scsi-fail"); !errors.Is(err, errTest) {
+			t.Fatalf("NewContainer error = %v, want %v", err, errTest)
+		}
+		if _, ok := c.containers["container-scsi-fail"]; ok {
+			t.Error("container should not be registered when SCSIController fails")
+		}
+	})
 }
 
 // TestListContainers verifies snapshots of the live container map.

internal/controller/pod/types_lcow.go

@@ -23,7 +23,7 @@ type vmController interface {
 	Guest() *guestmanager.Guest
 
 	// SCSIController returns the SCSI device controller for the VM.
-	SCSIController() *scsi.Controller
+	SCSIController(ctx context.Context) (*scsi.Controller, error)
 
 	// VPCIController returns the vPCI device controller for the VM.
 	VPCIController() *vpci.Controller