func (s IoImpl) ReadFile(filename string) ([]byte, error) {
	return s.readFile(filename)
}
ReadFile - real implementation of ReadFile backed by ioutil
package scan
import (
	"os"
	"path/filepath"
	"regexp"
	"github.com/swisscom/korp/docker_utils"
	"github.com/swisscom/korp/korp_utils"
	"github.com/swisscom/korp/string_utils"
	log "github.com/sirupsen/logrus"
	"github.com/urfave/cli"
	yaml "gopkg.in/yaml.v2"
	kustomize "sigs.k8s.io/kustomize/pkg/image"
	"sigs.k8s.io/kustomize/pkg/types"
)
const (
	dockerImageRefRegexStr = `(?m)image:\s*(?P<image>[^[{\s]+)\s+`
)
type Action struct {
	Io Io
}
type Io interface {
	ListYamlFilesPaths(rootPath string) ([]string, error)
	ReadFile(filename string) ([]byte, error)
	WriteFile(filename string, data []byte, perm os.FileMode) error
}
type IoImpl struct {
	listYamlFilesPaths func(rootPath string) ([]string, error)
	readFile           func(filename string) ([]byte, error)
	writeFile          func(filename string, data []byte, perm os.FileMode) error
}
func (s IoImpl) ListYamlFilesPaths(rootPath string) ([]string, error) {
	return s.listYamlFilesPaths(rootPath)
}