Add insert command in order to insert external files within an image

commands.go

@@ -42,6 +42,7 @@ func (srv *Server) Help() string {
 		{"images", "List images"},
 		{"import", "Create a new filesystem image from the contents of a tarball"},
 		{"info", "Display system-wide information"},
+		{"insert", "Insert a file in an image"},
 		{"inspect", "Return low-level information on a container"},
 		{"kill", "Kill a running container"},
 		{"login", "Register or Login to the docker registry server"},
@@ -65,6 +66,48 @@ func (srv *Server) Help() string {
 	return help
 }
 
+func (srv *Server) CmdInsert(stdin io.ReadCloser, stdout rcli.DockerConn, args ...string) error {
+	stdout.Flush()
+	cmd := rcli.Subcmd(stdout, "insert", "IMAGE URL PATH", "Insert a file from URL in the IMAGE at PATH")
+	if err := cmd.Parse(args); err != nil {
+		return nil
+	}
+	if cmd.NArg() != 3 {
+		cmd.Usage()
+		return nil
+	}
+	imageId := cmd.Arg(0)
+	url := cmd.Arg(1)
+	path := cmd.Arg(2)
+
+	img, err := srv.runtime.repositories.LookupImage(imageId)
+	if err != nil {
+		return err
+	}
+	file, err := Download(url, stdout)
+	if err != nil {
+		return err
+	}
+	defer file.Body.Close()
+
+	b := NewBuilder(srv.runtime)
+	c, err := b.Run(img, "echo", "insert", url, path)
+	if err != nil {
+		return err
+	}
+
+	if err := c.Inject(ProgressReader(file.Body, int(file.ContentLength), stdout, "Downloading %v/%v (%v)"), path); err != nil {
+		return err
+	}
+	// FIXME: Handle custom repo, tag comment, author
+	img, err = b.Commit(c, "", "", img.Comment, img.Author)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(stdout, "%s\n", img)
+	return nil
+}
+
 func (srv *Server) CmdBuild(stdin io.ReadCloser, stdout rcli.DockerConn, args ...string) error {
 	stdout.Flush()
 	cmd := rcli.Subcmd(stdout, "build", "[Dockerfile|-]", "Build a container from Dockerfile")

container.go

@@ -168,6 +168,18 @@ func (settings *NetworkSettings) PortMappingHuman() string {
 	return strings.Join(mapping, ", ")
 }
 
+// Inject the io.Reader at the given path. Note: do not close the reader
+func (container *Container) Inject(file io.Reader, pth string) error {
+	dest, err := os.Open(path.Join(container.rwPath(), pth))
+	if err != nil {
+		return err
+	}
+	if _, err := io.Copy(dest, file); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (container *Container) Cmd() *exec.Cmd {
 	return container.cmd
 }