Systemd with rtorrent in tmux

Question

I have been unable to get tmux & rtorrent running with a systemd service file. My rtorrent.service:

[Unit]
Description=rTorrent
Documentation=https://github.com/rakshasa/rtorrent
After=network.target local-fs.target

[Service]
Type=forking
KillMode=none
User=rtorrent
ExecStart=/usr/bin/tmux -S /tmp/rtorrent.sock new-session -d -s rtorrent \'rtorrent -n -O import=/etc/rtorrent.rc\'
ExecStop=/usr/bin/tmux -S /tmp/rtorrent.sock send-keys -t rtorrent C-q
WorkingDirectory=/home/rtorrent

[Install]
WantedBy=default.target

(Using Type=oneshot with RemainAfterExit=yes did not work, and I'm not convinced that is a solution anyway. I think running tmux this way ought to be done with Type=forking. Please correct me if I'm wrong!)

The output from systemctl status rtorrent:

● rtorrent.service - rTorrent
   Loaded: loaded (/etc/systemd/system/rtorrent.service; disabled)
   Active: failed (Result: exit-code) since Mon 2015-04-27 10:48:37 AEST; 22s ago
     Docs: https://github.com/rakshasa/rtorrent
  Process: 4433 ExecStart=/usr/bin/tmux -S /tmp/rtorrent.sock new-session -d -s rtorrent 'rtorrent -n -O import=/etc/rtorrent/rtorrent.rc' (code=exited, status=1/FAILURE)

Apr 27 10:48:37 vagrant tmux[4433]: usage: new-session [-AdDP] [-c start-directory] [-F format] [-n window-name] [-s session-name] [-t target-session] [-x width] [-y height] [command]
Apr 27 10:48:37 vagrant systemd[1]: rtorrent.service: control process exited, code=exited status=1
Apr 27 10:48:37 vagrant systemd[1]: Failed to start rTorrent.
Apr 27 10:48:37 vagrant systemd[1]: Unit rtorrent.service entered failed state.

Switching to the rtorrent user with su allows me to try the ExecStart command manually - which works fine. I'm at a loss to debug this further.

Thoughts? Thanks!

Answer 1

systemd does its own interpretation of values of Exec and other keys. Therefore, you shouldn't write as if this is going to be passed to sh -c or something like that. In particular, if you want to treat a set of words as a single argument, quote it as you normally would, and don't escape the quotes. Consider this example from the systemd docs:

Example:

ExecStart=/bin/echo one ; /bin/echo "two two"

This will execute /bin/echo two times, each time with one argument: one and two two, respectively. Because two commands are specified, Type=oneshot must be used.

So the ExecStart line should be:

ExecStart=/usr/bin/tmux -S /tmp/rtorrent.sock new-session -d -s rtorrent 'rtorrent -n -O import=/etc/rtorrent.rc'