github/linuxkit
1
0
Fork 0
mirror of https://github.com/linuxkit/linuxkit.git synced 2025-07-29 21:42:39 +00:00
Code Issues Projects Releases Wiki Activity

moby: Add 'kernel+squashfs' output

Browse Source 
This output produces a kernel and a root filesystem
in squashfs format. squashfs is a read-only, compressed
filesystem.

The 'kernel+squashfs' output can be used in a similar way as
the default 'kernel+initrd' output format with the benefit
that the rootfs does not consume any memory.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
This commit is contained in:
Rolf Neugebauer 2018-04-15 19:27:48 +01:00 committed by Rolf Neugebauer
parent 52cb0e1cfe
commit ad11be6b83
1 changed files with 63 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
src/moby/output.go
View File

@ -8,6 +8,7 @@ import (
"io/ioutil"
"os"
"runtime"
"strings"
"github.com/moby/tool/src/initrd"
log "github.com/sirupsen/logrus"
@ -19,6 +20,7 @@ var (
"iso-efi": "linuxkit/mkimage-iso-efi:343cf1a8ac0aba7d8a1f13b7f45fa0b57ab897dc",
"raw-bios": "linuxkit/mkimage-raw-bios:d90713b2dd610cf9a0f5f9d9095f8bf86f40d5c6",
"raw-efi": "linuxkit/mkimage-raw-efi:8938ffb6014543e557b624a40cce1714f30ce4b6",
"squashfs": "linuxkit/mkimage-squashfs:b44d00b0a336fd32c122ff32bd2b39c36a965135",
"gcp": "linuxkit/mkimage-gcp:e6cdcf859ab06134c0c37a64ed5f886ec8dae1a1",
"qcow2-efi": "linuxkit/mkimage-qcow2-efi:787b54906e14a56b9f1da35dcc8e46bd58435285",
"vhd": "linuxkit/mkimage-vhd:3820219e5c350fe8ab2ec6a217272ae82f4b9242",
@ -99,6 +101,13 @@ var outFuns = map[string]func(string, io.Reader, int) error{
}
return nil
},
"kernel+squashfs": func(base string, image io.Reader, size int) error {
err := outputKernelSquashFS(outputImages["squashfs"], base, image)
if err != nil {
return fmt.Errorf("Error writing kernel+squashfs output: %v", err)
}
return nil
},
"aws": func(base string, image io.Reader, size int) error {
filename := base + ".raw"
log.Infof(" %s", filename)
@ -427,3 +436,57 @@ func outputKernelInitrdTarball(base string, kernel []byte, initrd []byte, cmdlin
}
return tw.Close()
}
func outputKernelSquashFS(image, base string, filesystem io.Reader) error {
log.Debugf("output kernel/squashfs: %s %s", image, base)
log.Infof(" %s-squashfs.img", base)
tr := tar.NewReader(filesystem)
buf := new(bytes.Buffer)
rootfs := tar.NewWriter(buf)
for {
var thdr *tar.Header
thdr, err := tr.Next()
if err == io.EOF {
break
}
if err != nil {
return err
}
switch {
case thdr.Name == "boot/kernel":
kernel, err := ioutil.ReadAll(tr)
if err != nil {
return err
}
if err := ioutil.WriteFile(base+"-kernel", kernel, os.FileMode(0644)); err != nil {
return err
}
case thdr.Name == "boot/cmdline":
cmdline, err := ioutil.ReadAll(tr)
if err != nil {
return err
}
if err := ioutil.WriteFile(base+"-cmdline", cmdline, os.FileMode(0644)); err != nil {
return err
}
case strings.HasPrefix(thdr.Name, "boot/"):
// skip the rest of boot/
default:
rootfs.WriteHeader(thdr)
if _, err := io.Copy(rootfs, tr); err != nil {
return err
}
}
}
rootfs.Close()
output, err := os.Create(base + "-squashfs.img")
if err != nil {
return err
}
defer output.Close()
return dockerRun(buf, output, true, image)
}