local-server/boot-iso.go
2018-06-12 21:09:47 +11:00

192 lines
3.5 KiB
Go

package main
import (
"fmt"
"io"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
)
func buildBootISO(out io.Writer, ctx *renderContext) error {
tempDir, err := ioutil.TempDir("/tmp", "iso-")
if err != nil {
return err
}
defer os.RemoveAll(tempDir)
cp := func(src, dst string) error {
log.Printf("iso: adding %s as %s", src, dst)
in, err := os.Open(src)
if err != nil {
return err
}
defer in.Close()
outPath := filepath.Join(tempDir, dst)
if err := os.MkdirAll(filepath.Dir(outPath), 0755); err != nil {
return err
}
out, err := os.Create(outPath)
if err != nil {
return err
}
defer out.Close()
_, err = io.Copy(out, in)
return err
}
err = func() error {
// grub
if err := os.MkdirAll(filepath.Join(tempDir, "grub"), 0755); err != nil {
return err
}
err = ioutil.WriteFile(filepath.Join(tempDir, "grub", "grub.cfg"), []byte(`
search --set=root --file /config.yaml
insmod all_video
set timeout=3
menuentry "Direktil" {
linux /vmlinuz direktil.boot=DEVNAME=sr0 direktil.boot.fs=iso9660
initrd /initrd
}
`), 0644)
if err != nil {
return err
}
coreImgPath := filepath.Join(tempDir, "grub", "core.img")
grubCfgPath := filepath.Join(tempDir, "grub", "grub.cfg")
cmd := exec.Command("grub-mkstandalone",
"--format=i386-pc",
"--output="+coreImgPath,
"--install-modules=linux normal iso9660 biosdisk memdisk search tar ls",
"--modules=linux normal iso9660 biosdisk search",
"--locales=",
"--fonts=",
"boot/grub/grub.cfg="+grubCfgPath,
)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if err := cmd.Run(); err != nil {
return err
}
defer os.Remove(coreImgPath)
defer os.Remove(grubCfgPath)
out, err := os.Create(filepath.Join(tempDir, "grub", "bios.img"))
if err != nil {
return err
}
defer out.Close()
b, err := ioutil.ReadFile("/usr/lib/grub/i386-pc/cdboot.img")
if err != nil {
return err
}
if _, err := out.Write(b); err != nil {
return err
}
b, err = ioutil.ReadFile(coreImgPath)
if err != nil {
return err
}
if _, err := out.Write(b); err != nil {
return err
}
return nil
}()
if err != nil {
return err
}
// config
cfgBytes, cfg, err := ctx.Config()
if err != nil {
return err
}
ioutil.WriteFile(filepath.Join(tempDir, "config.yaml"), cfgBytes, 0600)
// kernel and initrd
type distCopy struct {
Src []string
Dst string
}
copies := []distCopy{
{Src: []string{"kernels", ctx.Group.Kernel}, Dst: "vmlinuz"},
{Src: []string{"initrd", ctx.Group.Initrd}, Dst: "initrd"},
}
// layers
for _, layer := range cfg.Layers {
layerVersion := ctx.Group.Versions[layer]
if layerVersion == "" {
return fmt.Errorf("layer %q not mapped to a version", layer)
}
copies = append(copies,
distCopy{
Src: []string{"layers", layer, layerVersion},
Dst: filepath.Join("current", "layers", layer+".fs"),
})
}
for _, copy := range copies {
outPath, err := ctx.distFetch(copy.Src...)
if err != nil {
return err
}
err = cp(outPath, copy.Dst)
if err != nil {
return err
}
}
// build the ISO
mkisofs, err := exec.LookPath("genisoimage")
if err != nil {
mkisofs, err = exec.LookPath("mkisofs")
}
if err != nil {
return err
}
cmd := exec.Command(mkisofs,
"-quiet",
"-joliet",
"-joliet-long",
"-rock",
"-translation-table",
"-no-emul-boot",
"-boot-load-size", "4",
"-boot-info-table",
"-eltorito-boot", "grub/bios.img",
"-eltorito-catalog", "grub/boot.cat",
tempDir,
)
cmd.Stdout = out
cmd.Stderr = os.Stderr
return cmd.Run()
}