upstart doesn’t start sh on first run, starts on subsequent runs

[Artyom Kazak]

Here’s an Upstart job, saved as /etc/init/r2.conf:

    setuid rtorrent
    exec screen -S rtorrent -fn -Dm rtorrent -n -o import=/tmp/rtconf

(rtorrent and screen are available from Ubuntu repositories.)

The first time I start it, everything is fine:

  # touch /tmp/rtconf <-- creating empty config; needed only once

  # service r2 start
  r2 start/running, process 1007

  # ps aux | grep rtorrent
  rtorrent 1007 0.0 0.3 24132 1520 ? Ss 20:13 0:00 SCREEN -S rtorrent -fn -Dm rtorrent -n -o import=/tmp/rtconf
  rtorrent 1008 0.2 1.2 262016 6388 pts/1 Ssl+ 20:13 0:00 rtorrent -n -o import=/tmp/rtconf

  # service r2 stop
  r2 stop/waiting

  # ps aux | grep rtorrent
  <nothing>

However, when I start it for the second time, “sh” appears from nowhere:

  # service r2 start
  r2 start/running, process 1021

  # ps aux | grep rtorrent
  rtorrent 1021 0.0 0.1 4436 628 ? Ss 20:14 0:00 /bin/sh -e -c screen -S rtorrent -fn -Dm rtorrent -n -o import=/tmp/rtconf /bin/sh
  rtorrent 1022 0.0 0.3 24132 1524 ? Ss 20:14 0:00 SCREEN -S rtorrent -fn -Dm rtorrent -n -o import=/tmp/rtconf
  rtorrent 1023 0.0 1.2 262016 6428 pts/2 Ssl+ 20:14 0:00 rtorrent -n -o import=/tmp/rtconf

What’s worse, due to this it doesn’t stop as expected:

  # service r2 stop
  r2 stop/waiting

  # ps aux | grep rtorrent
  rtorrent 1022 0.0 0.3 24132 1524 ? Ss 20:14 0:00 SCREEN -S rtorrent -fn -Dm rtorrent -n -o import=/tmp/rtconf
  rtorrent 1023 0.0 1.2 262016 6428 pts/2 Ssl+ 20:14 0:00 rtorrent -n -o import=/tmp/rtconf

The version of Ubuntu I’m using is 13.04 x64. The version of Upstart is 1.8-0ubuntu1.

[Artyom Kazak (artyom-kazak)]

Strangely enough, a possible workaround is to wrap “exec…” in “script … end script”.