bug#29773: urandom-seed-service should run earlier in the boot process

[ludo@gnu.org (Ludovic Courtès)]

Hello,

Leo Famulari <leo@famulari.name> skribis:

> On Thu, Dec 21, 2017 at 10:10:29AM +0100, Ludovic Courtès wrote:
>> 
>> The attached patch does the trick, AFAICS:
>> 
>
>> diff --git a/gnu/services/base.scm b/gnu/services/base.scm
>> index acc5c33f5..7fc8f6aa7 100644
>> --- a/gnu/services/base.scm
>> +++ b/gnu/services/base.scm
>> @@ -529,7 +529,10 @@ in KNOWN-MOUNT-POINTS when it is stopped."
>>    (list (shepherd-service
>>           (documentation "Preserve entropy across reboots for /dev/urandom.")
>>           (provision '(urandom-seed))
>> -         (requirement '(file-systems))
>> +
>> +         ;; Depend on udev so that /dev/hwrng is available.
>> +         (requirement '(file-systems udev))
>> +
>>           (start #~(lambda _
>>                      ;; On boot, write random seed into /dev/urandom.
>>                      (when (file-exists? #$%random-seed-file)
>
> Yes, it seems to work for me.

Great, I’ve pushed the whole series.

> I'm unsure if the stop action of urandom-seed-service is being executed
> on shutdown.
>
> I added some print statements and sleep delays to the stop action but
> the system halts faster than I expected and I don't see any writes to
> /var/lib/random-seed.

/var/lib/random-seed is definitely being updated on shutdown on my
system, as can be seen from its mtime.

Thanks,
Ludo’.