bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

[Dariqq]

When using guix home to manage shepherd services on a foreign 
distribution the shepherd package is also added to the home-profile.

This then makes the home profile provide 'halt', 'shutdown' and 'reboot' 
(and their manpages) masking the system ones.

Trying to run one of these then results in an error:
reboot: error: /var/run/shepherd/socket: No such file or directory

instead of e.g. rebooting the system.

bug#73903: (no subject)

[Jakob Honal via Bug reports for GNU Guix]

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bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

[Ludovic Courtès]

Hi,

Dariqq <dariqq@posteo.net> skribis:

> When using guix home to manage shepherd services on a foreign
> distribution the shepherd package is also added to the home-profile.
>
> This then makes the home profile provide 'halt', 'shutdown' and
> 'reboot' (and their manpages) masking the system ones.

Oh, indeed.  I’m not sure how to address that though.  Ideas?

Ludo’.

bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

[Dariqq]

Hi Ludo,

On 10.11.24 12:51, Ludovic Courtès wrote:
> Hi,
> 
> Dariqq <dariqq@posteo.net> skribis:
> 
>> When using guix home to manage shepherd services on a foreign
>> distribution the shepherd package is also added to the home-profile.
>>
>> This then makes the home profile provide 'halt', 'shutdown' and
>> 'reboot' (and their manpages) masking the system ones.
> 
> Oh, indeed.  I’m not sure how to address that though.  Ideas?
> 
Not sure if this is something that should be addressed by shepherd or 
the default shepherd package used for guix home.

Initially I had the idea to add a configure flag to shepherd to disable 
"building" and installing these 5 files (which is why I reported against 
shepherd). I threw something together that works but I am not really 
happy with it because imo such an option should disable *all*
  things that are not required when only using it for user level 
services and not just the entrypoints. That would be a lot more work though.

Another (simpler solution) would be to just solve the problem in guix by 
using a shepherd variant that deletes sbin and share/man/man8.


Wdyt?
> Ludo’.

bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

[Ludovic Courtès]

Hi,

Dariqq <dariqq@posteo.net> skribis:

> On 10.11.24 12:51, Ludovic Courtès wrote:
>> Hi,
>> Dariqq <dariqq@posteo.net> skribis:
>> 
>>> When using guix home to manage shepherd services on a foreign
>>> distribution the shepherd package is also added to the home-profile.
>>>
>>> This then makes the home profile provide 'halt', 'shutdown' and
>>> 'reboot' (and their manpages) masking the system ones.
>> Oh, indeed.  I’m not sure how to address that though.  Ideas?
>> 
> Not sure if this is something that should be addressed by shepherd or
> the default shepherd package used for guix home.

[...]

> Another (simpler solution) would be to just solve the problem in guix
> by using a shepherd variant that deletes sbin and share/man/man8.

Yes, this sounds like a reasonable solution to me.

Ludo’.

bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

[Dariqq]

Hi,

On 20.11.24 11:46, Ludovic Courtès wrote:

> 
>> Another (simpler solution) would be to just solve the problem in guix
>> by using a shepherd variant that deletes sbin and share/man/man8.
> 
> Yes, this sounds like a reasonable solution to me.
> 
> Ludo’.

How should this work? should this be a (public?) procedure? Should it 
rebuild shepherd or just copy the output with trivial-build-system?


I just thought of a more elegant solution, but this would be a lot 
harder to implement properly:

- Move the sbin stuff into a seperate output
- Home shepherd service only adds the main output to the profile and 
shepherd-root-service both
- Will need adjustments some packages that currently reference 
shutdown/reboot ( -> lots of rebuilds because logind) and the same 
change for the shepherd packages in the shepherd module.

bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

[Ludovic Courtès]

Hi,

Dariqq <dariqq@posteo.net> skribis:

> On 20.11.24 11:46, Ludovic Courtès wrote:
>
>> 
>>> Another (simpler solution) would be to just solve the problem in guix
>>> by using a shepherd variant that deletes sbin and share/man/man8.
>> Yes, this sounds like a reasonable solution to me.
>> Ludo’.
>
> How should this work? should this be a (public?) procedure? Should it
> rebuild shepherd or just copy the output with trivial-build-system?

My understanding of this proposal is that there would be a
“shepherd-foreign” package, which is like “shepherd” but without
‘reboot’ and ‘halt’.

That package could be implemented with ‘trivial-build-system’ or
‘copy-build-system’ indeed, and it would symlink all of ‘shepherd’,
except its ‘sbin’ directory.

> I just thought of a more elegant solution, but this would be a lot
> harder to implement properly:
>
> - Move the sbin stuff into a seperate output
> - Home shepherd service only adds the main output to the profile and
>   shepherd-root-service both
> - Will need adjustments some packages that currently reference
>   shutdown/reboot ( -> lots of rebuilds because logind) and the same
>   change for the shepherd packages in the shepherd module.

The advantage is that no extra step would be needed when using a foreign
distro.  But yeah, it’s relatively intrusive, and not my favorite
solution, FWIW.  Dunno.

WDYT?

Ludo’.

bug#73903: [shepherd]: Guix Home's shepherd masks shutdown/reboot on foreign distribution

[Dariqq]

Hi,

On 26.11.24 16:55, Ludovic Courtès wrote:
> Hi,
> 
> Dariqq <dariqq@posteo.net> skribis:
> 
>>
>> How should this work? should this be a (public?) procedure? Should it
>> rebuild shepherd or just copy the output with trivial-build-system?
> 
> My understanding of this proposal is that there would be a
> “shepherd-foreign” package, which is like “shepherd” but without
> ‘reboot’ and ‘halt’.
> 
> That package could be implemented with ‘trivial-build-system’ or
> ‘copy-build-system’ indeed, and it would symlink all of ‘shepherd’,
> except its ‘sbin’ directory.
> 

Imo it would make sense to have the sbinless shepherd be the default 
shepherd for home-shepherd s.t. the home environment never provides 
shutdown/halt by default. Those are commands are for the system to take 
care of (whether that is the shepherd coming from root-shepherd or the 
init from the foreign system).

On my foreign distro setup i am currently using this (apologies if the 
formatting turns out weird):

--8<---------------cut here---------------start------------->8---
(define shepherd-for-home
   (package
    (inherit shepherd)
    (name "shepherd-for-home")
    (source #f)
    (build-system trivial-build-system)
    (arguments
     (list
      #:modules '((guix build union)
                  (guix build utils))
      #:builder
      #~(begin
          (use-modules (guix build union)
                       (guix build utils))
          (union-build #$output
                       (list #$(this-package-input "shepherd"))
                       #:create-all-directories? #t)
          (delete-file-recursively (string-append #$output "/sbin"))
          (delete-file-recursively (string-append #$output 
"/share/man/man8")))))
    (native-inputs '())
    (inputs (list shepherd))))
--8<---------------cut here---------------end--------------->8---


If we don't want to care about the manpages then the 
(#:create-all-directories? #t) can be omitted in union-build.

>> I just thought of a more elegant solution, but this would be a lot
>> harder to implement properly:
>>
>> - Move the sbin stuff into a seperate output
>> - Home shepherd service only adds the main output to the profile and
>>    shepherd-root-service both
>> - Will need adjustments some packages that currently reference
>>    shutdown/reboot ( -> lots of rebuilds because logind) and the same
>>    change for the shepherd packages in the shepherd module.
> 
> The advantage is that no extra step would be needed when using a foreign
> distro.  But yeah, it’s relatively intrusive, and not my favorite
> solution, FWIW.  Dunno.
> 


If this would be possible without rebuilding I'd really like it because 
it makes clear what part of the shepherd something depends on (service 
manager stuff vs generic init stuff) and avoids an extra package that is 
just shepherd minus sbindir. But the 3300 dependants of logind makes 
this really unattractive.

> WDYT?
> 
> Ludo’.

Dariqq