Re: Packaging Slurm

[Ludovic Courtès]

Hi!

Jean-Christophe HAESSIG <haessigj@igbmc.fr> skribis:

> # strace -f -E GUIX_EXECUTION_ENGINE=fakechroot -E 
> LD_LIBRARY_PATH=/opt/slurm/gnu/store/j417whqiy5gz2rbmlnknla3wl43jgk1z-profile/lib/
>  
> /opt/slurm/sbin/slurmdbd -D

[...]

> The program hangs from there and is inoperative. The socket to the 
> database, which is in mode ugo+rwx is successfully used once, then the 
> program fiddles with its groups, gid, uid and then can't open it 
> anymore. I see that the /tmp/guix-exec-xxxx directory is created with 
> 0700 rights, which means it cannot be traversed anymore when the uid of 
> the program has changed.

Woow, interesting.  Clearly relocatable packs were primarily intended
for “regular” programs (not daemons), which is why you’re making these
interesting discoveries.  :-)

Off the top of my head, I’m not sure what the solution could be.  If you
feel so inclined, you can take a look at run-in-namespace.c in Guix,
which implements those execution engines.

>> Where “battle from /gnu/store” is the chicken-and-egg when booting,
>> right?  (That is, if /gnu/store is on NFS, then how do you boot.)
>
> Sure, it is even a problem with guix on a foreign distro, if you need 
> some of the software to be managed locally and the rest by shared nfs.
> My best bet would be to have guix recompiled to use an alternate 
> location as the store and the statedir, have it manage the local system 
> and let regular users take advantage of substitutes. I don't feel this 
> would be straightforward however.

Indeed; in general, using a non-standard store directory is a bad idea,
for many reasons (no substitutes, risks of failing builds just because
of the different store directory length, etc.).

I wonder if there might be a solution where you’d overlay the local
/gnu/store on top of the NFS-mounted store, something like that.  But I
don’t have the full picture of the setup you have.

Thanks,
Ludo’.