func createDevices(rootDir string, uid, gid int) error {
nullDir := fp.Join(rootDir, os.DevNull)
if err := osutil.Mknod(nullDir, unix.S_IFCHR|uint32(os.FileMode(0666)), 1*256+3); err != nil {
return err
}
if err := os.Lchown(nullDir, uid, gid); err != nil {
log.Debugf("Failed to lchown %s: %s\n", nullDir, err)
return err
}
zeroDir := fp.Join(rootDir, "/dev/zero")
if err := osutil.Mknod(zeroDir, unix.S_IFCHR|uint32(os.FileMode(0666)), 1*256+3); err != nil {
return err
}
if err := os.Lchown(zeroDir, uid, gid); err != nil {
log.Debugf("Failed to lchown %s: %s\n", zeroDir, err)
return err
}
for _, f := range []string{"/dev/random", "/dev/urandom"} {
randomDir := fp.Join(rootDir, f)
if err := osutil.Mknod(randomDir, unix.S_IFCHR|uint32(os.FileMode(0666)), 1*256+9); err != nil {
return err
}
if err := os.Lchown(randomDir, uid, gid); err != nil {
log.Debugf("Failed to lchown %s: %s\n", randomDir, err)
return err
}
}
return nil
}
// Mknod unless path does not exists.
func Mknod(path string, mode uint32, dev int) error {
if ExistsFile(path) {
return nil
}
log.Debugf("mknod %s %d %d", path, mode, dev)
if err := unix.Mknod(path, mode, dev); err != nil {
return err
}
return nil
}
// Symlink, but ignore already exists file.
func Symlink(oldname, newname string) error {
log.Debug("symlink", oldname, newname)
if err := os.Symlink(oldname, newname); err != nil {
// Ignore already created symlink
if _, ok := err.(*os.LinkError); !ok {
log.Debugf("Failed to symlink %s %s: %s", oldname, newname, err)
return err
}
}
return nil
}
func RunCmd(name string, arg ...string) error {
log.Debug("runcmd: ", name, arg)
out, err := exec.Command(name, arg...).CombinedOutput()
if len(out) > 0 {
log.Debug(string(out))
}
if err != nil {
log.Debugf("Failed to exec %s %s: %s", name, arg, err)
return err
}
return nil
}
func IsDirEmpty(dir string) bool {
f, err := os.Open(dir)
if err != nil {
log.Debugf("Failed to open %s: %s\n", dir, err)
return false
}
defer f.Close()
_, err = f.Readdirnames(1)
if err == io.EOF {
return true
}
return false
}
func Setuid(id int) error {
log.Debugf("setuid %d\n", id)
return system.Setuid(id)
}