// KernelOrOsRebootRequired returns whether a reboot is required to swith to the given OS or kernel snap.
func KernelOrOsRebootRequired(s *snap.Info) bool {
if s.Type != snap.TypeKernel && s.Type != snap.TypeOS {
return false
}
bootloader, err := partition.FindBootloader()
if err != nil {
logger.Noticef("cannot get boot settings: %s", err)
return false
}
var nextBoot, goodBoot string
switch s.Type {
case snap.TypeKernel:
nextBoot = "snap_try_kernel"
goodBoot = "snap_kernel"
case snap.TypeOS:
nextBoot = "snap_try_core"
goodBoot = "snap_core"
}
m, err := bootloader.GetBootVars(nextBoot, goodBoot)
if err != nil {
return false
}
squashfsName := filepath.Base(s.MountFile())
if m[nextBoot] == squashfsName && m[goodBoot] != m[nextBoot] {
return true
}
return false
}
// SetNextBoot will schedule the given OS or kernel snap to be used in
// the next boot
func SetNextBoot(s *snap.Info) error {
if release.OnClassic {
return nil
}
if s.Type != snap.TypeOS && s.Type != snap.TypeKernel {
return nil
}
bootloader, err := partition.FindBootloader()
if err != nil {
return fmt.Errorf("cannot set next boot: %s", err)
}
var bootvar string
switch s.Type {
case snap.TypeOS:
bootvar = "snap_try_core"
case snap.TypeKernel:
bootvar = "snap_try_kernel"
}
blobName := filepath.Base(s.MountFile())
if err := bootloader.SetBootVar(bootvar, blobName); err != nil {
return err
}
if err := bootloader.SetBootVar("snap_mode", "try"); err != nil {
return err
}
return nil
}
// ExtractKernelAssets extracts kernel/initrd/dtb data from the given
// kernel snap, if required, to a versioned bootloader directory so
// that the bootloader can use it.
func ExtractKernelAssets(s *snap.Info, snapf snap.Container) error {
if s.Type != snap.TypeKernel {
return fmt.Errorf("cannot extract kernel assets from snap type %q", s.Type)
}
bootloader, err := partition.FindBootloader()
if err != nil {
return fmt.Errorf("cannot extract kernel assets: %s", err)
}
if bootloader.Name() == "grub" {
return nil
}
// now do the kernel specific bits
blobName := filepath.Base(s.MountFile())
dstDir := filepath.Join(bootloader.Dir(), blobName)
if err := os.MkdirAll(dstDir, 0755); err != nil {
return err
}
dir, err := os.Open(dstDir)
if err != nil {
return err
}
defer dir.Close()
for _, src := range []string{"kernel.img", "initrd.img"} {
if err := snapf.Unpack(src, dstDir); err != nil {
return err
}
if err := dir.Sync(); err != nil {
return err
}
}
if err := snapf.Unpack("dtbs/*", dstDir); err != nil {
return err
}
return dir.Sync()
}
// SetNextBoot will schedule the given OS or kernel snap to be used in
// the next boot
func SetNextBoot(s *snap.Info) error {
if release.OnClassic {
return nil
}
if s.Type != snap.TypeOS && s.Type != snap.TypeKernel {
return nil
}
bootloader, err := partition.FindBootloader()
if err != nil {
return fmt.Errorf("cannot set next boot: %s", err)
}
var nextBoot, goodBoot string
switch s.Type {
case snap.TypeOS:
nextBoot = "snap_try_core"
goodBoot = "snap_core"
case snap.TypeKernel:
nextBoot = "snap_try_kernel"
goodBoot = "snap_kernel"
}
blobName := filepath.Base(s.MountFile())
// check if we actually need to do anything, i.e. the exact same
// kernel/core revision got installed again (e.g. firstboot)
m, err := bootloader.GetBootVars(goodBoot)
if err != nil {
return err
}
if m[goodBoot] == blobName {
return nil
}
return bootloader.SetBootVars(map[string]string{
nextBoot: blobName,
"snap_mode": "try",
})
}
func addMountUnit(s *snap.Info, meter progress.Meter) error {
squashfsPath := dirs.StripRootDir(s.MountFile())
whereDir := dirs.StripRootDir(s.MountDir())
sysd := systemd.New(dirs.GlobalRootDir, meter)
mountUnitName, err := sysd.WriteMountUnitFile(s.Name(), squashfsPath, whereDir, "squashfs")
if err != nil {
return err
}
// we need to do a daemon-reload here to ensure that systemd really
// knows about this new mount unit file
if err := sysd.DaemonReload(); err != nil {
return err
}
if err := sysd.Enable(mountUnitName); err != nil {
return err
}
return sysd.Start(mountUnitName)
}
func copyLocalSnapFile(snapPath, targetDir string, info *snap.Info) (dstPath string, err error) {
dst := filepath.Join(targetDir, filepath.Base(info.MountFile()))
return dst, osutil.CopyFile(snapPath, dst, 0)
}