Re: Shepherd user services that run on startup?

[Ben Weinstein-Raun <root@benwr.net>]

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On 12/20/23 16:42, Ben Weinstein-Raun wrote:
> My guess is that this is at least possible, by defining a system-level
> service that starts a shepherd for each user. Would that work?


After struggling with this for a week, I've managed to get a user-level
`shepherd` starting! It fails to actually run, probably due to errors in
my init.scm, but I'm happy with the progress! I still have some fairly
important-feeling questions though:

* When I tried to use `sudo` via the actual package, I get an error
about it needing to be setuid-root. My workaround is to jut directly add
/run/setuid-programs to the PATH, but this is a pretty bad-feeling hack,
as it leaves an unspecified dependency. What's the right way to depend
on sudo? Force the user to pass it in as an argument, maybe?
* I still don't know how to "properly" ensure that the XDG_RUNTIME_DIR
is set, like it should be for a "proper" login shell. Right now, the
shell script just brute-creates the directory where I expec
t it on my
system (and exports that path to the environment). So, if anybody knows:
what's the right way to do this?
* Several times throughout this process, when I had errors in the shell
script that caused it to exit early, my system shepherd became
unresponsive and I had to roll-back, and then reboot using
/proc/sysrq-trigger. This was a little terrifying, since I'm currently
traveling and won't physically see my server again until February. It
was also surprising, since the script is running inside a shepherd
fork-exec constructor, and I'd have thought that this would deal
gracefully with failed starts. Is this a bug in shepherd, or am I
misusing it?

> Anyone have tips on how to go about building this, if so? Especially: 
> What's the easiest way to ensure that a guix service knows the list of 
> users-with-login-shells on the system?


I sidestepped this issue by forcing the user to specify usernames when
instantiating the service. This seems nicer anyway, as m
aybe you don't
want to start a shepherd for every user.

> And, of course, is there a simpler way?

This question still stands!



My code is on github if you're curious:

* service definition is here:
https://github.com/benwr/benwr_guix/blob/main/benwr/services/userherd.scm
* package definition is here:
https://github.com/benwr/benwr_guix/blob/main/benwr/packages/userherd.scm
* shell script is here: https://github.com/benwr/userherd

(This is probably obvious, but just in case: I'd strongly caution
against directly relying on my channel, as I break it constantly)

Thanks in advance for any help!


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