// ManifestExclusiveLock gets an exclusive lock on only the pod manifest.
// This is used in the app sandbox - since the pod is already running, we
// won't be able to get an exclusive lock on the pod itself.
func (p *Pod) ExclusiveManifestLock() error {
if p.manifestLock != nil {
return p.manifestLock.ExclusiveLock() // This is idempotent
}
l, err := lock.ExclusiveLock(common.PodManifestLockPath(p.Path()), lock.RegFile)
if err != nil {
return err
}
p.manifestLock = l
return nil
}
// ExclusiveLockManifest gets an exclusive lock on only the pod manifest in the app sandbox.
// Since the pod is already running, we won't be able to get an exclusive lock on the pod itself.
func (p *Pod) ExclusiveLockManifest() error {
if !p.isRunning() {
return errors.New("pod is not running")
}
if p.manifestLock != nil {
return p.manifestLock.ExclusiveLock() // This is idempotent
}
l, err := lock.ExclusiveLock(common.PodManifestLockPath(p.Path()), lock.RegFile)
if err != nil {
return err
}
p.manifestLock = l
return nil
}
// Prepare sets up a pod based on the given config.
func Prepare(cfg PrepareConfig, dir string, uuid *types.UUID) error {
if err := os.MkdirAll(common.AppsInfoPath(dir), common.DefaultRegularDirPerm); err != nil {
return errwrap.Wrap(errors.New("error creating apps info directory"), err)
}
debug("Preparing stage1")
if err := prepareStage1Image(cfg, dir); err != nil {
return errwrap.Wrap(errors.New("error preparing stage1"), err)
}
var pmb []byte
var err error
if len(cfg.PodManifest) > 0 {
pmb, err = validatePodManifest(cfg, dir)
} else {
pmb, err = generatePodManifest(cfg, dir)
}
if err != nil {
return err
}
cfg.CommonConfig.ManifestData = string(pmb)
// create pod lock file for app add/rm operations.
f, err := os.OpenFile(common.PodManifestLockPath(dir), os.O_CREATE|os.O_RDWR, 0600)
if err != nil {
return err
}
f.Close()
debug("Writing pod manifest")
fn := common.PodManifestPath(dir)
if err := ioutil.WriteFile(fn, pmb, common.DefaultRegularFilePerm); err != nil {
return errwrap.Wrap(errors.New("error writing pod manifest"), err)
}
f, err = os.OpenFile(common.PodCreatedPath(dir), os.O_CREATE|os.O_RDWR, common.DefaultRegularFilePerm)
if err != nil {
return err
}
f.Close()
if cfg.UseOverlay {
// mark the pod as prepared with overlay
f, err := os.Create(filepath.Join(dir, common.OverlayPreparedFilename))
if err != nil {
return errwrap.Wrap(errors.New("error writing overlay marker file"), err)
}
defer f.Close()
}
if cfg.PrivateUsers.Shift > 0 {
// mark the pod as prepared for user namespaces
uidrangeBytes := cfg.PrivateUsers.Serialize()
if err := ioutil.WriteFile(filepath.Join(dir, common.PrivateUsersPreparedFilename), uidrangeBytes, common.DefaultRegularFilePerm); err != nil {
return errwrap.Wrap(errors.New("error writing userns marker file"), err)
}
}
return nil
}