Function TestDoPrepareIDMappedOverlay

core/mount/mount_linux_test.go:306–405

(t *testing.T)

}

func TestDoPrepareIDMappedOverlay(t *testing.T) {
	testutil.RequiresRoot(t)

	k512 := kernel.KernelVersion{Kernel: 5, Major: 12}
	ok, err := kernel.GreaterEqualThan(k512)
	require.NoError(t, err)
	if !ok {
		t.Skip("GetUsernsFD requires kernel >= 5.12")
	}

	usernsFD, err := getUsernsFD(testUIDMaps, testGIDMaps)
	require.NoError(t, err)
	defer usernsFD.Close()

	type testCase struct {
		name              string
		injectUmountFault bool
	}

	tcases := []testCase{
		{
			name:              "normal",
			injectUmountFault: false,
		},
		{
			name:              "umount-fault",
			injectUmountFault: true,
		},
	}

	for _, tc := range tcases {
		t.Run(tc.name, func(t *testing.T) {
			fakeLowerDirsDir := t.TempDir()
			if !supportsIDMap(fakeLowerDirsDir) {
				t.Skip("IDmapped mounts not supported on filesystem selected by t.TempDir()")
			}

			lowerDirs := []string{filepath.Join(fakeLowerDirsDir, "lower1"), filepath.Join(fakeLowerDirsDir, "lower2")}
			for _, dir := range lowerDirs {
				require.NoError(t, os.Mkdir(dir, 0755))
				require.NoError(t, os.WriteFile(filepath.Join(dir, filepath.Base(dir)), []byte("foo"), 0644))
			}

			remountsLocation := t.TempDir()

			tmpLowerDirs, cleanup, err := doPrepareIDMappedOverlay(remountsLocation, lowerDirs, int(usernsFD.Fd()))
			require.NoError(t, err)
			require.Len(t, tmpLowerDirs, len(lowerDirs))

			lowerContents := make([][]byte, len(lowerDirs))

			for i, dir := range lowerDirs {
				correspondingRemount := tmpLowerDirs[i]
				filename := filepath.Base(dir)

				expectedFile, err := os.ReadFile(filepath.Join(dir, filename))
				require.NoError(t, err, "reading comparison test fixture file")
				lowerContents[i] = expectedFile