Ensure file path exists

Author: maxbrunet

internal/ebutil/mock_mounter_test.go

@@ -101,6 +101,13 @@ func remount(m mounter, src, dest string) error {
 	if err := m.MkdirAll(destDir, 0o750); err != nil {
 		return fmt.Errorf("ensure path: %w", err)
 	}
+	if !stat.IsDir() {
+		f, err := m.OpenFile(dest, os.O_CREATE, 0o640)
+		if err != nil {
+			return fmt.Errorf("ensure file path: %w", err)
+		}
+		defer f.Close()
+	}
 	if err := m.Mount(src, dest, "bind", syscall.MS_BIND, ""); err != nil {
 		return fmt.Errorf("bind mount %s => %s: %w", src, dest, err)
 	}
@@ -114,14 +121,16 @@ func remount(m mounter, src, dest string) error {
 type mounter interface {
 	// GetMounts wraps procfs.GetMounts
 	GetMounts() ([]*procfs.MountInfo, error)
+	// Stat wraps os.Stat
+	Stat(string) (os.FileInfo, error)
 	// MkdirAll wraps os.MkdirAll
 	MkdirAll(string, os.FileMode) error
+	// OpenFile wraps os.OpenFile
+	OpenFile(string, int, os.FileMode) (*os.File, error)
 	// Mount wraps syscall.Mount
 	Mount(string, string, string, uintptr, string) error
 	// Unmount wraps syscall.Unmount
 	Unmount(string, int) error
-	// Stat wraps os.Stat
-	Stat(string) (os.FileInfo, error)
 }
 
 // realMounter implements mounter and actually does the thing.
@@ -145,6 +154,10 @@ func (m *realMounter) MkdirAll(path string, perm os.FileMode) error {
 	return os.MkdirAll(path, perm)
 }
 
+func (m *realMounter) OpenFile(name string, flag int, perm os.FileMode) (*os.File, error) {
+	return os.OpenFile(name, flag, perm)
+}
+
 func (m *realMounter) Stat(path string) (os.FileInfo, error) {
 	return os.Stat(path)
 }

internal/ebutil/remount.go

@@ -53,10 +53,12 @@ func Test_tempRemount(t *testing.T) {
 		mm.EXPECT().GetMounts().Return(mounts, nil)
 		mm.EXPECT().Stat("/usr/bin/utility").Return(&fakeFileInfo{isDir: false}, nil)
 		mm.EXPECT().MkdirAll("/.test/usr/bin", os.FileMode(0o750)).Times(1).Return(nil)
+		mm.EXPECT().OpenFile("/.test/usr/bin/utility", os.O_CREATE, os.FileMode(0o640)).Times(1).Return(new(os.File), nil)
 		mm.EXPECT().Mount("/usr/bin/utility", "/.test/usr/bin/utility", "bind", uintptr(syscall.MS_BIND), "").Times(1).Return(nil)
 		mm.EXPECT().Unmount("/usr/bin/utility", 0).Times(1).Return(nil)
 		mm.EXPECT().Stat("/.test/usr/bin/utility").Return(&fakeFileInfo{isDir: false}, nil)
 		mm.EXPECT().MkdirAll("/usr/bin", os.FileMode(0o750)).Times(1).Return(nil)
+		mm.EXPECT().OpenFile("/usr/bin/utility", os.O_CREATE, os.FileMode(0o640)).Times(1).Return(new(os.File), nil)
 		mm.EXPECT().Mount("/.test/usr/bin/utility", "/usr/bin/utility", "bind", uintptr(syscall.MS_BIND), "").Times(1).Return(nil)
 		mm.EXPECT().Unmount("/.test/usr/bin/utility", 0).Times(1).Return(nil)