func NewColdMigrator(cfg Config) (Migrator, error) {
	migrator := &coldMigrator{
		dockerHomeDir: cfg.DockerHomeDir,
		allContainers: make(map[string]bool),
		images:        make(map[string]struct{}),
	}
	return migrator, nil
}
NewColdMigrator creates a migrator tool instance.
package migrator
import (
	"context"
	"fmt"
	"path"
	"strings"
	"time"
	"github.com/pouchcontainer/d2p-migrator/ctrd"
	"github.com/pouchcontainer/d2p-migrator/docker"
	"github.com/pouchcontainer/d2p-migrator/pouch"
	"github.com/pouchcontainer/d2p-migrator/pouch/convertor"
	localtypes "github.com/pouchcontainer/d2p-migrator/pouch/types"
	"github.com/pouchcontainer/d2p-migrator/utils"
	pouchtypes "github.com/alibaba/pouch/apis/types"
	dockerclient "github.com/docker/engine-api/client"
	"github.com/sirupsen/logrus"
)
func init() {
	Register("cold-migrate", NewColdMigrator)
}
type coldMigrator struct {
	dockerHomeDir string
	upperDirMappingList []*upperDirMapping
	allContainers map[string]bool
	runningContainers []string
	images map[string]struct{}
}
type upperDirMapping struct {
	srcDir string
	dstDir string
}