Crouton: cannot get cron to work

[city41]

After setting up a crouton chroot, cron does not seem to work.

What I've done:

1. setup crouton following steps in README
2. sudo enter-chroot
3. crontab -e
4. added * * * * * echo "hi from cron" >> /home/matt/hiFromCron.txt"
5. after a few minutes, see no output at either /home/matt within the chroot or at the "real" /home/matt outside of the chroot (I went there and added a matt directory)

ps -A | grep cron returns nothing. It definitely looks like cron is not running.

But doing sudo /etc/init.d/cron start just produces "Rather than invoking init scripts through /etc/init.d, use the service(8) ..."

So I do sudo service cron start and get "Unknown job: cron"

And sudo start cron gives me "start: Unknown job: cron"

I'm not convinced this is a Crouton specific issue, but hoping I can get some pointers on what to try next.

[dnschneid]

crouton doesn't use upstart, so you need to run crond explicitly, probably from the chroot's /etc/rc.local. Look inside /etc/init/cron for the commands needed to launch crond.

[city41]

Thanks, it looks to be sudo cron is all that is needed to get cron started.

[dnschneid]

Cool! Thanks for sharing your findings.

[alexluecke]

Exactly what I needed. Thanks both y'all.

[laurenweinstein1]

What is the best way to run scripts inside the chroot at shutdown or reboot, for cleanup, etc.? Thanks!

[dnschneid]

There's no official mechanism for it at the moment. You may be able to make a script that gets run from rc.local that does nothing but wait for SIGTERM, and then performs your cleanup tasks. unmount-chroot will SIGTERM all child processes if it can't unmount everything, and then SIGKILL five seconds later (so hopefully your cleanup takes less than five seconds :) ).

[laurenweinstein1]

Hmm. Thanks. Five seconds can be pretty tight for some stuff though.

[dnschneid]

You could modify unmount-chroot to change that timeout. Otherwise, you'll probably have to try some other approach. Also worth noting is that while there's a system dbus message that gets fired on shutdown, crouton doesn't actually respond to it, so even the SIGTERM approach may not work for the shutdown case...