func LoadImage(root string) (*Image, error) {
// Load the json data
jsonData, err := ioutil.ReadFile(jsonPath(root))
if err != nil {
return nil, err
}
img := &Image{}
if err := json.Unmarshal(jsonData, img); err != nil {
return nil, err
}
if err := utils.ValidateID(img.ID); err != nil {
return nil, err
}
if buf, err := ioutil.ReadFile(path.Join(root, "layersize")); err != nil {
if !os.IsNotExist(err) {
return nil, err
}
// If the layersize file does not exist then set the size to a negative number
// because a layer size of 0 (zero) is valid
img.Size = -1
} else {
size, err := strconv.Atoi(string(buf))
if err != nil {
return nil, err
}
img.Size = int64(size)
}
return img, nil
}
// FIXME: Do more extensive tests (ex: create multiple, delete, recreate;
// create multiple, check the amount of images and paths, etc..)
func TestGraphCreate(t *testing.T) {
graph, _ := tempGraph(t)
defer nukeGraph(graph)
archive, err := fakeTar()
if err != nil {
t.Fatal(err)
}
img, err := graph.Create(archive, "", "", "Testing", "", nil, nil)
if err != nil {
t.Fatal(err)
}
if err := utils.ValidateID(img.ID); err != nil {
t.Fatal(err)
}
if img.Comment != "Testing" {
t.Fatalf("Wrong comment: should be '%s', not '%s'", "Testing", img.Comment)
}
if img.DockerVersion != dockerversion.VERSION {
t.Fatalf("Wrong docker_version: should be '%s', not '%s'", dockerversion.VERSION, img.DockerVersion)
}
images, err := graph.Map()
if err != nil {
t.Fatal(err)
} else if l := len(images); l != 1 {
t.Fatalf("Wrong number of images. Should be %d, not %d", 1, l)
}
if images[img.ID] == nil {
t.Fatalf("Could not find image with id %s", img.ID)
}
}
// Register imports a pre-existing image into the graph.
// FIXME: pass img as first argument
func (graph *Graph) Register(jsonData []byte, layerData archive.ArchiveReader, img *image.Image) (err error) {
defer func() {
// If any error occurs, remove the new dir from the driver.
// Don't check for errors since the dir might not have been created.
// FIXME: this leaves a possible race condition.
if err != nil {
graph.driver.Remove(img.ID)
}
}()
if err := utils.ValidateID(img.ID); err != nil {
return err
}
// (This is a convenience to save time. Race conditions are taken care of by os.Rename)
if graph.Exists(img.ID) {
return fmt.Errorf("Image %s already exists", img.ID)
}
// Ensure that the image root does not exist on the filesystem
// when it is not registered in the graph.
// This is common when you switch from one graph driver to another
if err := os.RemoveAll(graph.ImageRoot(img.ID)); err != nil && !os.IsNotExist(err) {
return err
}
// If the driver has this ID but the graph doesn't, remove it from the driver to start fresh.
// (the graph is the source of truth).
// Ignore errors, since we don't know if the driver correctly returns ErrNotExist.
// (FIXME: make that mandatory for drivers).
graph.driver.Remove(img.ID)
tmp, err := graph.Mktemp("")
defer os.RemoveAll(tmp)
if err != nil {
return fmt.Errorf("Mktemp failed: %s", err)
}
// Create root filesystem in the driver
if err := graph.driver.Create(img.ID, img.Parent); err != nil {
return fmt.Errorf("Driver %s failed to create image rootfs %s: %s", graph.driver, img.ID, err)
}
// Mount the root filesystem so we can apply the diff/layer
rootfs, err := graph.driver.Get(img.ID, "")
if err != nil {
return fmt.Errorf("Driver %s failed to get image rootfs %s: %s", graph.driver, img.ID, err)
}
defer graph.driver.Put(img.ID)
img.SetGraph(graph)
if err := image.StoreImage(img, jsonData, layerData, tmp, rootfs); err != nil {
return err
}
// Commit
if err := os.Rename(tmp, graph.ImageRoot(img.ID)); err != nil {
return err
}
graph.idIndex.Add(img.ID)
return nil
}