Am 23.06.2015 um 14:18 schrieb Richard Weinberger:
Am 22.06.2015 um 16:51 schrieb Daniel P. Berrange:
On Mon, Jun 22, 2015 at 04:40:37PM +0200, Richard Weinberger wrote:
Hi!
Why is libvirt-lxc issuing a setsid() in lxcContainerSetupFDs()? To me it seems like a hack to have a controlling TTY if PID 1 is /bin/bash.
I honestly can't remember the reason. It might have been to ensure we have separation from the libvirt_lxc session.
Hm, can be.
If one runs a sysv init style distro (like Debian) in libvirt-lxc the setsid() has a major downside, when getty spawns a login shell on /dev/tty1 it cannot become the controlling tty. Hence, if one presses ctrl-c in such a session, the container will reboot.
Is that problem due to the fact we call setsid(), or due to use calling ioctl(TIOCSCTTY) ?
If I remove the TIOCSCTTY nothing changes. Without setsid() libvirt is unable to start the container at all. So, I fear you're right that it has something do to with the libvirt session.
Found a way to deal with that. Patch is on the way. The setsid() really only seems to be there to have a controlling TTY if PID 1 is bash. Thanks, //richard