how to print values inside shepherd service gexp

how to print values inside shepherd service gexp

[Vladilen Kozin]

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Hello. I probably have all phases screwed up in my head now.

(shepherd-service
  (start
#~(make-forkexec-constructor
                   some-command
                   #:directory (pk #$twgter-directory)
                   #:log-file (pk #$twgter-log-file))
))

If we instantiate this process in our OS declaration under services and
then run that OS inside a container and `herd start this-service`, where
would the above (pk ..) values show up? They aren't in /var/log/messages
and they aren't in whatever #:log-file we specified. I imagine this gexp
turns into a Guile script somewhere inside the store and Shepherd runs it
when we start the service.

More generally, how to I print stuff inside gexps that are part of services.

Thank you

-- 
Best regards
Vlad Kozin

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Re: how to print values inside shepherd service gexp

[Attila Lendvai]

> (shepherd-service
> (start
> #~(make-forkexec-constructor
> some-command
> #:directory (pk #$twgter-directory)
> #:log-file (pk #$twgter-log-file))
> ))
> 
> If we instantiate this process in our OS declaration under services
> and then run that OS inside a container and `herd start
> this-service`, where would the above (pk ..) values show up? They
> aren't in /var/log/messages and they aren't in whatever #:log-file we
> specified. I imagine this gexp turns into a Guile script somewhere
> inside the store and Shepherd runs it when we start the service.


my understanding is that they will run when shepherd starts the
service, and it should land in /var/log/messages.

but in my experience shepherd's handling of logs and stdout should
receive some more care.

e.g. errors from the start GEXP are not logged, and if an error
happens before your pk's, then you won't see any sign of them.

i have a commit that i'm testing locally that addresses that:

https://github.com/attila-lendvai-patches/shepherd/commits/attila

HTH,

-- 
• attila lendvai
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--
“What you do speaks so loud I cannot hear what you say.”
	— Ralph Waldo Emerson (1803–1882)