blob: fb5f674c84a858ec44fb2a11c327281fbed0e387 [file] [log] [blame]
package image
import (
// TypeLayers is used for RootFS.Type for filesystems organized into layers.
const TypeLayers = "layers"
// typeLayersWithBase is an older format used by Windows up to v1.12. We
// explicitly handle this as an error case to ensure that a daemon which still
// has an older image like this on disk can still start, even though the
// image itself is not usable. See
const typeLayersWithBase = "layers+base"
// RootFS describes images root filesystem
// This is currently a placeholder that only supports layers. In the future
// this can be made into an interface that supports different implementations.
type RootFS struct {
Type string `json:"type"`
DiffIDs []layer.DiffID `json:"diff_ids,omitempty"`
// NewRootFS returns empty RootFS struct
func NewRootFS() *RootFS {
return &RootFS{Type: TypeLayers}
// Append appends a new diffID to rootfs
func (r *RootFS) Append(id layer.DiffID) {
r.DiffIDs = append(r.DiffIDs, id)
// Clone returns a copy of the RootFS
func (r *RootFS) Clone() *RootFS {
newRoot := NewRootFS()
newRoot.Type = r.Type
newRoot.DiffIDs = append(r.DiffIDs)
return newRoot
// ChainID returns the ChainID for the top layer in RootFS.
func (r *RootFS) ChainID() layer.ChainID {
if runtime.GOOS == "windows" && r.Type == typeLayersWithBase {
logrus.Warnf("Layer type is unsupported on this platform. DiffIDs: '%v'", r.DiffIDs)
return ""
return layer.CreateChainID(r.DiffIDs)