Add output types for BIOS and EFI ISOs

Note that the EFI ISO is not yet automatically sized, and the
kernel command lines are currently hard coded in the builders.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

moby/output.go

@@ -0,0 +1,101 @@
+package main
+
+import (
+	"archive/tar"
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+const (
+	bios = "mobylinux/mkimage-iso-bios:6b3ef6d6bdcc5fdf2ee683febac99533c2268c89@sha256:2484146c4dfbd2eee83d9dd3adf84d9232e5dd739d8762275dcd50bf60a529c6"
+	efi  = "mobylinux/mkimage-iso-efi:40f35270037dae95584324427e56f829756ff145@sha256:ae5b37ae560a5e030342f3d493d4ad611f2694bcd54eba86bf42ca069da986a7"
+)
+
+func outputs(m *Moby, bzimage []byte, initrd []byte) error {
+	for _, o := range m.Outputs {
+		switch o.Format {
+		case "kernel+initrd":
+			err := outputKernelInitrd(bzimage, initrd)
+			if err != nil {
+				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
+			}
+		case "iso-bios":
+			err := outputISO(bios, "mobylinux.iso", bzimage, initrd)
+			if err != nil {
+				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
+			}
+		case "iso-efi":
+			err := outputISO(efi, "mobylinux-efi.iso", bzimage, initrd)
+			if err != nil {
+				return fmt.Errorf("Error writing %s output: %v", o.Format, err)
+			}
+		case "":
+			return fmt.Errorf("No format specified for output")
+		default:
+			return fmt.Errorf("Unknown output type %s", o.Format)
+		}
+	}
+	return nil
+}
+
+// TODO add kernel command line
+func outputISO(image, filename string, bzimage []byte, initrd []byte) error {
+	// first build the input tarball from kernel and initrd
+	buf := new(bytes.Buffer)
+	tw := tar.NewWriter(buf)
+	hdr := &tar.Header{
+		Name: "bzImage",
+		Mode: 0600,
+		Size: int64(len(bzimage)),
+	}
+	err := tw.WriteHeader(hdr)
+	if err != nil {
+		return err
+	}
+	_, err = tw.Write(bzimage)
+	if err != nil {
+		return err
+	}
+	hdr = &tar.Header{
+		Name: "initrd.img",
+		Mode: 0600,
+		Size: int64(len(initrd)),
+	}
+	err = tw.WriteHeader(hdr)
+	if err != nil {
+		return err
+	}
+	_, err = tw.Write(initrd)
+	if err != nil {
+		return err
+	}
+	err = tw.Close()
+	if err != nil {
+		return err
+	}
+	iso, err := dockerRunInput(buf, image)
+	if err != nil {
+		return err
+	}
+	err = ioutil.WriteFile(filename, iso, os.FileMode(0644))
+	if err != nil {
+		return err
+	}
+	fmt.Println(filename)
+	return nil
+}
+
+func outputKernelInitrd(bzimage []byte, initrd []byte) error {
+	err := ioutil.WriteFile("initrd.img", initrd, os.FileMode(0644))
+	if err != nil {
+		return err
+	}
+	err = ioutil.WriteFile("bzImage", bzimage, os.FileMode(0644))
+	if err != nil {
+		return err
+	}
+	fmt.Println("bzImage initrd.img")
+	return nil
+}