Re: init / supervisor in jail

From: Andriy Gapon <avg_at_freebsd.org>
Date: Tue, 11 Nov 2025 12:14:47 UTC
On 10/11/2025 21:16, James Gritton wrote:
> Far from being a kludge, I think it's a feature we need, and one at the top of 
> my list.  Forcing it to look like PID 1 from jailed perspective is definitely 
> doable (and something I'd done outside of the project a decade ago).  In 
> addition to those two requirements, I would add one that answers your last 
> question:
> 
> 3. signals to init and reboot(2) work as they would on the host side.
> 
> A jailed reboot would kill all processes and restart rc, and possibly do other 
> kernel-side cleanups yet to be clearly defined.  A jailed halt would remove the 
> jail.  A jailed single-user mode could exist where instead of init spawning a 
> shell, it just sits around while the system has a chance to jexec into it.
> 
> init handles various signals by rebooting/halting/etc, and it should be able to 
> do that as it does now, by calling reboot(2), directing the kernel to do what it 
> needs to with the jail.  If init goes away, it's probably like a halt and 
> removes the jail.
> 
> This is definitely something that will be happening.

Thank you very much.
That's good to hear.

-- 
Andriy Gapon