Respect user defined/default sizes on upgrade (#587)

pkg/types/v1/common.go

@@ -36,7 +36,7 @@ const (
 // ImageSource represents the source from where an image is created for easy identification
 type ImageSource struct {
 	source  string `yaml:"source"`
-	srcType string
+	srcType string `yaml:"type"`
 }
 
 func (i ImageSource) Value() string {

pkg/types/v1/fs.go

@@ -37,4 +37,5 @@ type FS interface {
 	OpenFile(name string, flag int, perm fs.FileMode) (*os.File, error)
 	WriteFile(filename string, data []byte, perm os.FileMode) error
 	Rename(oldpath, newpath string) error
+	Truncate(name string, size int64) error
 }