package graph import ( "fmt" "io" "github.com/docker/docker/engine" "github.com/docker/docker/image" "github.com/docker/docker/pkg/log" ) func (s *TagStore) Install(eng *engine.Engine) error { for name, handler := range map[string]engine.Handler{ "image_set": s.CmdSet, "image_tag": s.CmdTag, "tag": s.CmdTagLegacy, // FIXME merge with "image_tag" "image_get": s.CmdGet, "image_inspect": s.CmdLookup, "image_tarlayer": s.CmdTarLayer, "image_export": s.CmdImageExport, "history": s.CmdHistory, "images": s.CmdImages, "viz": s.CmdViz, "load": s.CmdLoad, "import": s.CmdImport, "pull": s.CmdPull, "push": s.CmdPush, } { if err := eng.Register(name, handler); err != nil { return fmt.Errorf("Could not register %q: %v", name, err) } } return nil } // CmdSet stores a new image in the graph. // Images are stored in the graph using 4 elements: // - A user-defined ID // - A collection of metadata describing the image // - A directory tree stored as a tar archive (also called the "layer") // - A reference to a "parent" ID on top of which the layer should be applied // // NOTE: even though the parent ID is only useful in relation to the layer and how // to apply it (ie you could represent the full directory tree as 'parent_layer + layer', // it is treated as a top-level property of the image. This is an artifact of early // design and should probably be cleaned up in the future to simplify the design. // // Syntax: image_set ID // Input: // - Layer content must be streamed in tar format on stdin. An empty input is // valid and represents a nil layer. // // - Image metadata must be passed in the command environment. // 'json': a json-encoded object with all image metadata. // It will be stored as-is, without any encoding/decoding artifacts. // That is a requirement of the current registry client implementation, // because a re-encoded json might invalidate the image checksum at // the next upload, even with functionaly identical content. func (s *TagStore) CmdSet(job *engine.Job) engine.Status { if len(job.Args) != 1 { return job.Errorf("usage: %s NAME", job.Name) } var ( imgJSON = []byte(job.Getenv("json")) layer = job.Stdin ) if len(imgJSON) == 0 { return job.Errorf("mandatory key 'json' is not set") } // We have to pass an *image.Image object, even though it will be completely // ignored in favor of the redundant json data. // FIXME: the current prototype of Graph.Register is stupid and redundant. img, err := image.NewImgJSON(imgJSON) if err != nil { return job.Error(err) } if err := s.graph.Register(imgJSON, layer, img); err != nil { return job.Error(err) } return engine.StatusOK } // CmdGet returns information about an image. // If the image doesn't exist, an empty object is returned, to allow // checking for an image's existence. func (s *TagStore) CmdGet(job *engine.Job) engine.Status { if len(job.Args) != 1 { return job.Errorf("usage: %s NAME", job.Name) } name := job.Args[0] res := &engine.Env{} img, err := s.LookupImage(name) // Note: if the image doesn't exist, LookupImage returns // nil, nil. if err != nil { return job.Error(err) } if img != nil { // We don't directly expose all fields of the Image objects, // to maintain a clean public API which we can maintain over // time even if the underlying structure changes. // We should have done this with the Image object to begin with... // but we didn't, so now we're doing it here. // // Fields that we're probably better off not including: // - Config/ContainerConfig. Those structs have the same sprawl problem, // so we shouldn't include them wholesale either. // - Comment: initially created to fulfill the "every image is a git commit" // metaphor, in practice people either ignore it or use it as a // generic description field which it isn't. On deprecation shortlist. res.SetAuto("Created", img.Created) res.Set("Author", img.Author) res.Set("Os", img.OS) res.Set("Architecture", img.Architecture) res.Set("DockerVersion", img.DockerVersion) res.Set("Id", img.ID) res.Set("Parent", img.Parent) } res.WriteTo(job.Stdout) return engine.StatusOK } // CmdLookup return an image encoded in JSON func (s *TagStore) CmdLookup(job *engine.Job) engine.Status { if len(job.Args) != 1 { return job.Errorf("usage: %s NAME", job.Name) } name := job.Args[0] if image, err := s.LookupImage(name); err == nil && image != nil { if job.GetenvBool("raw") { b, err := image.RawJson() if err != nil { return job.Error(err) } job.Stdout.Write(b) return engine.StatusOK } out := &engine.Env{} out.Set("Id", image.ID) out.Set("Parent", image.Parent) out.Set("Comment", image.Comment) out.SetAuto("Created", image.Created) out.Set("Container", image.Container) out.SetJson("ContainerConfig", image.ContainerConfig) out.Set("DockerVersion", image.DockerVersion) out.Set("Author", image.Author) out.SetJson("Config", image.Config) out.Set("Architecture", image.Architecture) out.Set("Os", image.OS) out.SetInt64("Size", image.Size) if _, err = out.WriteTo(job.Stdout); err != nil { return job.Error(err) } return engine.StatusOK } return job.Errorf("No such image: %s", name) } // CmdTarLayer return the tarLayer of the image func (s *TagStore) CmdTarLayer(job *engine.Job) engine.Status { if len(job.Args) != 1 { return job.Errorf("usage: %s NAME", job.Name) } name := job.Args[0] if image, err := s.LookupImage(name); err == nil && image != nil { fs, err := image.TarLayer() if err != nil { return job.Error(err) } defer fs.Close() if written, err := io.Copy(job.Stdout, fs); err != nil { return job.Error(err) } else { log.Debugf("rendered layer for %s of [%d] size", image.ID, written) } return engine.StatusOK } return job.Errorf("No such image: %s", name) }