bug#64775: /run should be cleaned on boot

[Hilton Chain]

On Mon, 07 Aug 2023 04:06:37 +0800,
Vagrant Cascadian wrote:
>
> [1  <text/plain (7bit)>]
> On 2023-08-06, Hilton Chain wrote:
> > On Sat, 22 Jul 2023 04:24:17 +0800,
> > Saku Laesvuori via Bug reports for GNU Guix wrote:
> >>
> >> [1  <text/plain; us-ascii (quoted-printable)>]
> >> > > I vote for TMPFS, since that would also reduce flash wear.
> >> > > Honestly I don't get why it's not already using TMPFS.
> >> >
> >> > One argument could be how much ram it takes:
> >> >
> >> >   $ du -sc /run/*
> >> >   12      /run/blkid
> >> >   0       /run/booted-system
> >> >   0       /run/current-system
> >> >   1312    /run/setuid-programs
> >> >   524     /run/udev
> >> >   1848    total
> >> >
> >> > That is with no explicit setuid programs configured, on a machine with a
> >> > fairly minimal configuration.
> >> >
> >> > Not a *huge* amount of ram, but not nothing, either...
> >>
> >> I'd say it's effectively nothing for almost all devices capable of
> >> running Guix. On my laptop the size of /run is 4804 (4.7M). In a quick
> >> test one terminal window with only zsh running in it took almost 10
> >> times as much ram.
> >> [2 signature.asc <application/pgp-signature (7bit)>]
> >> No public key for 257D284A2A1D3A32 created at 2023-07-22T04:24:17+0800 
> >> using RSA
> >
> > I'm currently using tmpfs for /tmp, /run and /var/run on my Guix
> > Systems.
> >
> > If you are interested, this is my base file systems:
> > --8<---------------cut here---------------start------------->8---
> > (cons* (file-system
> >          (device "none")
> >          (mount-point "/tmp")
> >          (type "tmpfs")
> >          (check? #f))
> >
> >        (file-system
> >          (device "none")
> >          (mount-point "/run")
> >          (type "tmpfs")
> >          (needed-for-boot? #t)
> >          (check? #f))
> >
> >        (file-system
> >          (device "none")
> >          (mount-point "/var/run")
> >          (type "tmpfs")
> >          (needed-for-boot? #t)
> >          (check? #f))
>
> You probably want to restrict permissions on /run and /var/run, as the
> defaults for tmpfs are world-writeable, allowing any user or process to
> create files or directories in potentially harmful ways...
>
> For /tmp, these defaults are appropriate, however tricky a
> world-writeable directory is...

I have set the mode and size limit on them.

Thank you so much!  Otherwise I won't notice that...

> Although I rarely have enough spare ram on a system to have /tmp be
> tmpfs for Guix System because builds happen there by default, and
> occasionally I need a lot more space than available ram in some cases.

I have enough RAM for builds I currently do on my laptop and it's the
builder for other systems, so tmpfs is fine for me.

Thanks