// Atomic deploy by symlink
// 1. rsync maindir => backupdir
// 2. mv -T backuplink destdir
// 3. rsync srcdir => maindir
// 4. mv -T mainlink destdir
func DeployWithSymlink(srcDir, destDir string) error {
mainLink := destDir + ".drootmain"
backupLink := destDir + ".drootbackup"
mainDir := destDir + ".d/main"
backupDir := destDir + ".d/backup"
for _, dir := range []string{mainDir, backupDir} {
if err := fileutils.CreateIfNotExists(dir, true); err != nil { // mkdir -p
return fmt.Errorf("Failed to create directory %s: %s", dir, err)
}
}
// Return error if the working directory that droot internally uses exists
for _, link := range []string{mainLink, backupLink, destDir} {
if !osutil.IsSymlink(link) && (osutil.ExistsFile(link) || osutil.ExistsDir(link)) {
return fmt.Errorf("%s already exists. Please use another directory as --dest option or delete %s", link, link)
}
}
if err := osutil.Symlink(mainDir, mainLink); err != nil {
return fmt.Errorf("Failed to create symlink %s: %s", mainLink, err)
}
if err := osutil.Symlink(backupDir, backupLink); err != nil {
return fmt.Errorf("Failed to create symlink %s: %s", backupLink, err)
}
log.Info("-->", "Syncing", "from", mainDir, "to", backupDir)
if err := Rsync(mainDir, backupDir); err != nil {
return fmt.Errorf("Failed to rsync: %s", err)
}
log.Info("-->", "Renaming", "from", backupLink, "to", destDir)
if err := os.Rename(backupLink, destDir); err != nil {
return fmt.Errorf("Failed to rename %s: %s", destDir, err)
}
log.Info("-->", "Syncing", "from", srcDir, "to", mainDir)
if err := Rsync(srcDir, mainDir); err != nil {
return fmt.Errorf("Failed to rsync: %s", err)
}
log.Info("-->", "Renaming", "from", mainLink, "to", destDir)
if err := os.Rename(mainLink, destDir); err != nil {
return fmt.Errorf("Failed to rename %s: %s", destDir, err)
}
return nil
}
func doRun(c *cli.Context) error {
command := c.Args()
if len(command) < 1 {
cli.ShowCommandHelp(c, "run")
return errors.New("command required")
}
optRootDir := c.String("root")
if optRootDir == "" {
cli.ShowCommandHelp(c, "run")
return errors.New("--root option required")
}
rootDir, err := mounter.ResolveRootDir(optRootDir)
if err != nil {
return err
}
// Check env format KEY=VALUE
env := c.StringSlice("env")
if len(env) > 0 {
for _, e := range env {
if len(strings.SplitN(e, "=", 2)) != 2 {
return fmt.Errorf("Invalid env format: %s", e)
}
}
}
uid, gid := os.Getuid(), os.Getgid()
if group := c.String("group"); group != "" {
if gid, err = osutil.LookupGroup(group); err != nil {
return fmt.Errorf("Failed to lookup group: %s", err)
}
}
if user := c.String("user"); user != "" {
if uid, err = osutil.LookupUser(user); err != nil {
return fmt.Errorf("Failed to lookup user: %s", err)
}
}
// copy files
if c.Bool("copy-files") {
for _, f := range copyFiles {
srcFile, destFile := fp.Join("/", f), fp.Join(rootDir, f)
if err := osutil.Cp(srcFile, destFile); err != nil {
return fmt.Errorf("Failed to copy %s: %s", f, err)
}
if err := os.Lchown(destFile, uid, gid); err != nil {
return fmt.Errorf("Failed to lchown %s: %s", f, err)
}
}
}
mnt := mounter.NewMounter(rootDir)
if err := mnt.MountSysProc(); err != nil {
return err
}
for _, val := range c.StringSlice("bind") {
hostDir, containerDir, err := parseBindOption(val)
if err != nil {
return err
}
if err := mnt.BindMount(hostDir, containerDir); err != nil {
return err
}
}
for _, val := range c.StringSlice("robind") {
hostDir, containerDir, err := parseBindOption(val)
if err != nil {
return err
}
if err := mnt.RoBindMount(hostDir, containerDir); err != nil {
return fmt.Errorf("Failed to robind mount %s: %s", val, err)
}
}
// create symlinks
if err := osutil.Symlink("../run/lock", fp.Join(rootDir, "/var/lock")); err != nil {
return fmt.Errorf("Failed to symlink lock file: %s", err)
}
if err := createDevices(rootDir, uid, gid); err != nil {
return fmt.Errorf("Failed to create devices: %s", err)
}
if err := osutil.Chroot(rootDir); err != nil {
return fmt.Errorf("Failed to chroot: %s", err)
}
if !c.Bool("no-dropcaps") {
if err := osutil.DropCapabilities(keepCaps); err != nil {
return fmt.Errorf("Failed to drop capabilities: %s", err)
}
}
if err := osutil.Setgid(gid); err != nil {
return fmt.Errorf("Failed to set group %d: %s", gid, err)
}
if err := osutil.Setuid(uid); err != nil {
return fmt.Errorf("Failed to set user %d: %s", uid, err)
}
if osutil.ExistsFile(environ.DROOT_ENV_FILE_PATH) {
envFromFile, err := environ.GetEnvironFromEnvFile(environ.DROOT_ENV_FILE_PATH)
if err != nil {
return fmt.Errorf("Failed to read environ from '%s'", environ.DROOT_ENV_FILE_PATH)
}
env, err = environ.MergeEnviron(envFromFile, env)
if err != nil {
return fmt.Errorf("Failed to merge environ: %s", err)
}
}
return osutil.Execv(command[0], command[0:], env)
}