// setupImage attempts to load the image by the given hash from the store,
// verifies that the image matches the given hash and extracts the image
// into a directory in the given dir.
// It returns the AppManifest that the image contains
func setupImage(cfg Config, img types.Hash, dir string) (*schema.AppManifest, error) {
log.Println("Loading image", img.String())
rs, err := cfg.Store.ReadStream(img.String())
if err != nil {
return nil, err
}
ad := rktpath.AppImagePath(dir, img)
err = os.MkdirAll(ad, 0776)
if err != nil {
return nil, fmt.Errorf("error creating image directory: %v", err)
}
hash := sha256.New()
r := io.TeeReader(rs, hash)
if err := ptar.ExtractTar(tar.NewReader(r), ad); err != nil {
return nil, fmt.Errorf("error extracting ACI: %v", err)
}
// Tar does not necessarily read the complete file, so ensure we read the entirety into the hash
if _, err := io.Copy(ioutil.Discard, r); err != nil {
return nil, fmt.Errorf("error reading ACI: %v", err)
}
if id := fmt.Sprintf("%x", hash.Sum(nil)); id != img.Val {
if err := os.RemoveAll(ad); err != nil {
fmt.Fprintf(os.Stderr, "error cleaning up directory: %v\n", err)
}
return nil, fmt.Errorf("image hash does not match expected (%v != %v)", id, img.Val)
}
err = os.MkdirAll(filepath.Join(ad, "rootfs/tmp"), 0777)
if err != nil {
return nil, fmt.Errorf("error creating tmp directory: %v", err)
}
mpath := rktpath.AppManifestPath(dir, img)
f, err := os.Open(mpath)
if err != nil {
return nil, fmt.Errorf("error opening app manifest: %v", err)
}
b, err := ioutil.ReadAll(f)
if err != nil {
return nil, fmt.Errorf("error reading app manifest: %v", err)
}
var am schema.AppManifest
if err := json.Unmarshal(b, &am); err != nil {
return nil, fmt.Errorf("error unmarshaling app manifest: %v", err)
}
return &am, nil
}
// RelAppImagePath returns the path of an application image relative to the
// stage1 chroot
func RelAppImagePath(imageID types.Hash) string {
return filepath.Join(stage2Dir, imageID.String())
}
// AppImagePath returns the path where an app image (i.e. unpacked ACI) is rooted (i.e.
// where its contents are extracted during stage0), based on the app image ID.
func AppImagePath(root string, imageID types.Hash) string {
return filepath.Join(root, Stage1Dir, stage2Dir, imageID.String())
}
// SocketUnitName returns a systemd socket unit name for the given imageID
func SocketUnitName(imageID types.Hash) string {
return imageID.String() + ".socket"
}
// ServiceUnitName returns a systemd service unit name for the given imageID
func ServiceUnitName(imageID types.Hash) string {
return imageID.String() + ".service"
}