// isMounted returns true if the given path is a mountpoint
func isMounted(path string) (bool, error) {
cmd := exec.Command(mountpointCmd, path)
// mountpoint uses translated messages, ensure we get the
// english ones
cmd.Env = []string{"LC_ALL=C"}
output, err := cmd.CombinedOutput()
exitCode, err := osutil.ExitCode(err)
// if we get anything other than "ExitError" er error here
if err != nil {
return false, err
}
// mountpoint.c from util-linux always returns 0 or 1
// (unless e.g. signal)
if exitCode != 0 && exitCode != 1 {
return false, fmt.Errorf("got unexpected exit code %v from the mountpoint command: %s", exitCode, output)
}
// exitCode == 0 means it is a mountpoint, do we are done
if exitCode == 0 {
return true, nil
}
// exitCode == 1 either means something went wrong *or*
// the path is not a mount point
// (thanks mountpoint.c :/)
if strings.Contains(string(output), "is not a mountpoint") {
return false, nil
}
return false, fmt.Errorf("unexpected output from mountpoint: %s (%v)", output, exitCode)
}
// run calls systemctl with the given args, returning its standard output (and wrapped error)
func run(args ...string) ([]byte, error) {
bs, err := exec.Command("systemctl", args...).CombinedOutput()
if err != nil {
exitCode, _ := osutil.ExitCode(err)
return nil, &Error{cmd: args, exitCode: exitCode, msg: bs}
}
return bs, nil
}
// jctl calls journalctl to get the JSON logs of the given services, wrapping the error if any.
func jctl(svcs []string) ([]byte, error) {
cmd := []string{"journalctl", "-o", "json"}
for i := range svcs {
cmd = append(cmd, "-u", svcs[i])
}
bs, err := exec.Command(cmd[0], cmd[1:]...).Output() // journalctl can be messy with its stderr
if err != nil {
exitCode, _ := osutil.ExitCode(err)
return nil, &Error{cmd: cmd, exitCode: exitCode, msg: bs}
}
return bs, nil
}
// Lowlevel copy the snap data (but never override existing data)
func copySnapDataDirectory(oldPath, newPath string) (err error) {
if _, err := os.Stat(oldPath); err == nil {
if _, err := os.Stat(newPath); err != nil {
// there is no golang "CopyFile"
cmd := exec.Command("cp", "-a", oldPath, newPath)
if err := cmd.Run(); err != nil {
if exitCode, err := osutil.ExitCode(err); err == nil {
return &ErrDataCopyFailed{
OldPath: oldPath,
NewPath: newPath,
ExitCode: exitCode}
}
return err
}
}
}
return nil
}