Re: starting jails within jails using rc

From: James Gritton <jamie_at_freebsd.org>
Date: Sun, 15 Aug 2021 09:29:59 -0700
On 2021-08-14 12:59, Dan Langille wrote:
> The problem:
> 
> The parent jail cannot automatically start the child jail. The child
> jail can be started manually.
> 
> Running this command in the parent child succeeds: service jail start 
> freshports
> 
> Why? I think it's because /etc/rc.d/jail contains:
> 
> # KEYWORD: nojail shutdown
> 
> This tells the rc system not to run the jail script if the host is a 
> jail.
> 
> How can I trick it?
> 
> My two ideas so far:
> 
> * remove the keyword from the script (I've tested this; it works)
> * duplicate the script, removing the keyword from the script
> * mangle security.jail.jailed in the parent jail it thinks it's not in
> a jail and runs it anyway
> 
> The downsides to these:
> 
> * the first two require I keep up to date with the jail script.
> * the last one will have unintended consequences I'm sure, many which
> I most likely would not like.

Since jails with jails is a supported (though not defaulted) feature,
I see no reason why simply removing the "nojail" keyword from the
script shouldn't be the default.  The only cost is typical jail
startup having to run the script to no effect, but the rc system is
already built of dozens of such seldom-used scripts.

- Jamie
Received on Sun Aug 15 2021 - 16:29:59 UTC

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