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I have an upstart service defined as:


description    "Lenik's secret tunnel thru *"
author        "谢继雷 (Lenik)"

start on (net-device-up IFACE!=lo)
stop on runlevel[!2345]


    # -T disable pseudo-tty allocation
    # -f go to background after login but before command exec
    # -n stdin from /dev/null, must be used when ssh is run in bg.
    # -N no command
    # -D "dynamic" app-level port forwarding.
    sudo -usshproxy ssh -qTfn -ND *:7878

end script

But the ssh tunnel seems to be zombied after some hours, so I want to restart it each hour, how to do it within this .conf file, or should I write another cron.hourly job?

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up vote 2 down vote accepted

Rather than restart the service at fixed intervals, you could restart the service when the connection dies. Pass the ServerAliveInterval option to make ssh detect a broken connection faster. Use the respawn directive in the Upstart script to have the tunnel restarted automatically. Alternatively, use an ssh tunnel restarting program such as autossh.

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Great information! – Xiè Jìléi Nov 26 '10 at 1:59
+1. Heck, I think that this answer should have been accepted instead. – whitequark Nov 26 '10 at 5:40

While "events generated at timed intervals" is a planned feature in Upstart, it is not ready to provide that yet. So you should write a simple script like this:

service sshproxy restart 

And put it into /etc/cron.hourly folder. Don't forget to set an executable bit (chmod +x /etc/cron.hourly/, or it will not start.

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Do user cron scripts are run in sudo mode? – Xiè Jìléi Nov 25 '10 at 2:49
No, they are run as the user they belong to, i.e. like if you'd call them manually from terminal when logged in as that user. – whitequark Nov 25 '10 at 2:58
Like most of Upstart, it is a planned feature. It's a really cool idea, but not actually implemented yet. – Tim Williscroft Nov 26 '10 at 1:08
@Tim, Upstart is currently replaces init nicely, and all of its planned features are, actually, replacing other Unix daemons. – whitequark Nov 26 '10 at 5:39
You can also do put initctl emit a_custom_event in cron, and add or a_custom_event to the start on line in the upstart job – nafg Nov 27 '13 at 11:26

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