fix NodeStageVolume tests

Unit tests were initiating test driver without a custom mounter which
results in using FakeExec with DisableScripts set to true.

This approach does not allow for any control over fake command return
values. This causes the resize flow of mount-utils code to fail while
parsing the fake command output.

We can use custom mounter with predefined action list instead to have
full control of the fake return values.

pkg/gce-pd-csi-driver/node_test.go

@@ -15,7 +15,10 @@ package gceGCEDriver
 
 import (
 	"context"
+	"fmt"
 	"io/ioutil"
+	"k8s.io/utils/exec"
+	testingexec "k8s.io/utils/exec/testing"
 	"os"
 	"path/filepath"
 	"testing"
@@ -61,6 +64,15 @@ func getTestBlockingGCEDriver(t *testing.T, readyToExecute chan chan struct{}) *
 	return gceDriver
 }
 
+func makeFakeCmd(fakeCmd *testingexec.FakeCmd, cmd string, args ...string) testingexec.FakeCommandAction {
+	c := cmd
+	a := args
+	return func(cmd string, args ...string) exec.Cmd {
+		command := testingexec.InitFakeCmd(fakeCmd, c, a...)
+		return command
+	}
+}
+
 func TestNodeGetVolumeStats(t *testing.T) {
 	gceDriver := getTestGCEDriver(t)
 	ns := gceDriver.ns
@@ -349,8 +361,6 @@ func TestNodeUnpublishVolume(t *testing.T) {
 }
 
 func TestNodeStageVolume(t *testing.T) {
-	gceDriver := getTestGCEDriver(t)
-	ns := gceDriver.ns
 	volumeID := "project/test001/zones/c1/disks/testDisk"
 	blockCap := &csi.VolumeCapability_Block{
 		Block: &csi.VolumeCapability_BlockVolume{},
@@ -434,6 +444,61 @@ func TestNodeStageVolume(t *testing.T) {
 	}
 	for _, tc := range testCases {
 		t.Logf("Test case: %s", tc.name)
+		actionList := []testingexec.FakeCommandAction{
+			makeFakeCmd(
+				&testingexec.FakeCmd{
+					CombinedOutputScript: []testingexec.FakeAction{
+						func() ([]byte, []byte, error) {
+							return []byte(fmt.Sprintf("DEVNAME=/dev/sdb\nTYPE=ext4")), nil, nil
+						},
+					},
+				},
+				"blkid",
+			),
+			makeFakeCmd(
+				&testingexec.FakeCmd{
+					CombinedOutputScript: []testingexec.FakeAction{
+						func() ([]byte, []byte, error) {
+							return []byte("1"), nil, nil
+						},
+					},
+				},
+				"blockdev",
+			),
+			makeFakeCmd(
+				&testingexec.FakeCmd{
+					CombinedOutputScript: []testingexec.FakeAction{
+						func() ([]byte, []byte, error) {
+							return []byte("1"), nil, nil
+						},
+					},
+				},
+				"blockdev",
+			),
+			makeFakeCmd(
+				&testingexec.FakeCmd{
+					CombinedOutputScript: []testingexec.FakeAction{
+						func() ([]byte, []byte, error) {
+							return []byte(fmt.Sprintf("DEVNAME=/dev/sdb\nTYPE=ext4")), nil, nil
+						},
+					},
+				},
+				"blkid",
+			),
+			makeFakeCmd(
+				&testingexec.FakeCmd{
+					CombinedOutputScript: []testingexec.FakeAction{
+						func() ([]byte, []byte, error) {
+							return []byte(fmt.Sprintf("block size: 1\nblock count: 1")), nil, nil
+						},
+					},
+				},
+				"dumpe2fs",
+			),
+		}
+		mounter := mountmanager.NewFakeSafeMounterWithCustomExec(&testingexec.FakeExec{CommandScript: actionList})
+		gceDriver := getTestGCEDriverWithCustomMounter(t, mounter)
+		ns := gceDriver.ns
 		_, err := ns.NodeStageVolume(context.Background(), tc.req)
 		if err != nil {
 			serverError, ok := status.FromError(err)