[lxc-devel] [RFC] catching sys_reboot syscall

[Pavel Machek]

Hi!

> In this case, the container shutdowns correctly but, at the end, the
> init process is waiting indefinitely and we have the containers stuck
> with one process (the init process).
> 
> In order to fix that, we used a hypervisor process, parent of the
> container's init process, watching for the container's utmp file and
> detecting when the runlevel changes. When this runlevel change is
> detected we wait for the container to have one process left and then we
> kill the container's init.
> 
> That works well if we modify the distro configuration files, we make
> /var/run to not be a tmpfs and we remove all the files inside this
> directory when the container boots. *But* as soon as we upgrade the
> container distro, all the tweaks are lost. So this method works but at
> the cost of tweaking the containers configuration files again and again,
> each time there is an update, which is not tolerable in a production
> environment.
> 
> This problem is easy to solve with a small hack in the kernel:

Hmm. If you just made sys_reboot() equivalent to exit() for container
case... perhaps patch would be even simpler..?

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