bug#64455: shepherd: unable to use redefined system/system* in 0.10.1

bug#64455: shepherd: unable to use redefined system/system* in 0.10.1

[buma2023]

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Hello,

I am using happily shepherd since a few years as my init system on
Debian: amd64 (desktop and notebook), armhf (Cubox).

I was using 0.9.1 with guile-3.0.5 and fibers-1.1.1.

I recently tried 0.10.1 with guile-3.0.9 and fibers 1.3.1 and
encountered a problem with using system and system* in my services:
the simple fact to have the symbol system or system* in
/etc/shepherd.scm or included files (even if the command is not
executed) leads to a misbehaving shepherd, more specifically the
shepherd socket disappears; the system boots but with multiple
instances of the launched daemons.

If a system/system* command is executed while booting, shepherd
blocks at the point of its execution.

Example of service causing the failure:

(register-services
 (make <service>
   #:provides '(mytest)
   #:start (lambda args
           (system "touch /tmp/somefile")
           #t)
   ))

The service is not started at boot, I have to do it manually afterwards,
but I never can go there, as the shepherd socket is missing.

I I add at the end of /etc/shepherd.scm:
(system "touch /tmp/somefile")

I have the same problem.

Strangely at build time the test tests/system-star.sh succeeds, and
after I have booted (without refering to a system/system* command) , I
can run:

# export PID=$$; herd eval root "(system \"echo success! >/proc/$PID/fd/1\")"

(in my case, output appears in /var/log/syslog so I need the redirection)

I have read a bit documentation and code to be aware that system and
system* were redefined in shepherd to be non blocking, I suspect the
problem is how this is done.

I would prefer to have new names in shepherd for the redefined
system/system* and keep the old ones intact.

I have a workaround for this problem: replacing system/system* by
helpers I use, like:

(define (system-value command)
  "Return first line of output when calling (system command)"
  (let* ((port (open-input-pipe command))
       (str (read-line port)))
    (close-pipe port)
    str))

but this is a band-aid.


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bug#64455: shepherd: unable to use redefined system/system* in 0.10.1

[Ludovic Courtès]

Hi,

"buma2023@outlook.fr" <buma2023@outlook.fr> skribis:

> I am using happily shepherd since a few years as my init system on
> Debian: amd64 (desktop and notebook), armhf (Cubox).

Interesting!  I didn’t know of such uses.

> I was using 0.9.1 with guile-3.0.5 and fibers-1.1.1.
>
> I recently tried 0.10.1 with guile-3.0.9 and fibers 1.3.1 and
> encountered a problem with using system and system* in my services:
> the simple fact to have the symbol system or system* in
> /etc/shepherd.scm or included files (even if the command is not
> executed) leads to a misbehaving shepherd, more specifically the
> shepherd socket disappears; the system boots but with multiple
> instances of the launched daemons.
>
> If a system/system* command is executed while booting, shepherd
> blocks at the point of its execution.
>
> Example of service causing the failure:
>
> (register-services
>  (make <service>
>    #:provides '(mytest)
>    #:start (lambda args
>            (system "touch /tmp/somefile")
>            #t)
>    ))
>
> The service is not started at boot, I have to do it manually afterwards,
> but I never can go there, as the shepherd socket is missing.

I can reproduce it like this:

--8<---------------cut here---------------start------------->8---
$ cat /tmp/t.conf
(register-services
 (make <service>
   #:provides '(mytest)
   #:start (lambda args
             (system "touch /tmp/somefile")
             #t)))

(start 'mytest)
$ shepherd -I -c/tmp/t.conf -s /tmp/sock 
Starting service root...
Service root started.
Service root running with value #t.
Service root has been started.
Starting service mytest...
  C-c C-z
[1]+  Stopped                 shepherd -I -c/tmp/t.conf -s /tmp/sock
$ bg
[1]+ shepherd -I -c/tmp/t.conf -s /tmp/sock &
$ herd -s /tmp/sock status
herd: error: /tmp/sock: Connection refused
--8<---------------cut here---------------end--------------->8---

This is both with 0.10.1 and with
d5ed516e736ce473902cc86b5cf4f61f27ebb642.

To be continued…

Ludo’.

bug#64455: shepherd: unable to use redefined system/system* in 0.10.1

[Ludovic Courtès]

Hi,

Ludovic Courtès <ludo@gnu.org> skribis:

> "buma2023@outlook.fr" <buma2023@outlook.fr> skribis:
>
>> I am using happily shepherd since a few years as my init system on
>> Debian: amd64 (desktop and notebook), armhf (Cubox).
>
> Interesting!  I didn’t know of such uses.
>
>> I was using 0.9.1 with guile-3.0.5 and fibers-1.1.1.
>>
>> I recently tried 0.10.1 with guile-3.0.9 and fibers 1.3.1 and
>> encountered a problem with using system and system* in my services:
>> the simple fact to have the symbol system or system* in
>> /etc/shepherd.scm or included files (even if the command is not
>> executed) leads to a misbehaving shepherd, more specifically the
>> shepherd socket disappears; the system boots but with multiple
>> instances of the launched daemons.
>>
>> If a system/system* command is executed while booting, shepherd
>> blocks at the point of its execution.
>>
>> Example of service causing the failure:
>>
>> (register-services
>>  (make <service>
>>    #:provides '(mytest)
>>    #:start (lambda args
>>            (system "touch /tmp/somefile")
>>            #t)
>>    ))
>>
>> The service is not started at boot, I have to do it manually afterwards,
>> but I never can go there, as the shepherd socket is missing.
>
> I can reproduce it like this:
>
> $ cat /tmp/t.conf
> (register-services
>  (make <service>
>    #:provides '(mytest)
>    #:start (lambda args
>              (system "touch /tmp/somefile")
>              #t)))
>
> (start 'mytest)
> $ shepherd -I -c/tmp/t.conf -s /tmp/sock 
> Starting service root...
> Service root started.
> Service root running with value #t.
> Service root has been started.
> Starting service mytest...
>   C-c C-z
> [1]+  Stopped                 shepherd -I -c/tmp/t.conf -s /tmp/sock
> $ bg
> [1]+ shepherd -I -c/tmp/t.conf -s /tmp/sock &
> $ herd -s /tmp/sock status
> herd: error: /tmp/sock: Connection refused
>
> This is both with 0.10.1 and with
> d5ed516e736ce473902cc86b5cf4f61f27ebb642.

Sorry, the bug is reproducible with 0.10.1 but *not* with
d5ed516e736ce473902cc86b5cf4f61f27ebb642.

I believe this was fixed by Shepherd commit
2b310bd3b0ba0d7a08c77b456d34369cd6444edb (that is, after 0.10.1).

I think I’ll release 0.10.2 within a couple of weeks, but it would be
great if you could confirm that current Shepherd ‘master’ works for you.

Thanks!

Ludo’.

bug#64455: shepherd: unable to use redefined system/system* in 0.10.1

[urb59]

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‌Hello,

Sorry for the late reply, but release 0.10.2 didn't fix the issue.

Current workaround: suppressing redefinition of system/system* and suppressing running tests/system-star.sh

I am open to suggestions of how to help you debug that.

Don't reply to buma2023, it was me, but it's a throw away address no longer valid.
>Hi,
>
>Ludovic Courtès <ludo <at> gnu.org> skribis:
>
>> "buma2023 <at> outlook.fr" <buma2023 <at> outlook.fr> skribis:
>>
>>> I am using happily shepherd since a few years as my init system on
>>> Debian: amd64 (desktop and notebook), armhf (Cubox).
>>
>> Interesting!  I didn’t know of such uses.
>>
>>> I was using 0.9.1 with guile-3.0.5 and fibers-1.1.1.
>>>
>>> I recently tried 0.10.1 with guile-3.0.9 and fibers 1.3.1 and
>>> encountered a problem with using system and system* in my services:
>>> the simple fact to have the symbol system or system* in
>>> /etc/shepherd.scm or included files (even if the command is not
>>> executed) leads to a misbehaving shepherd, more specifically the
>>> shepherd socket disappears; the system boots but with multiple
>>> instances of the launched daemons.
>>>
>>> If a system/system* command is executed while booting, shepherd
>>> blocks at the point of its execution.
>>>
>>> Example of service causing the failure:
>>>
>>> (register-services
>>>  (make <service>
>>>    #:provides '(mytest)
>>>    #:start (lambda args
>>>       (system "touch /tmp/somefile")
>>>       #t)
>>>    ))
>>>
>>> The service is not started at boot, I have to do it manually afterwards,
>>> but I never can go there, as the shepherd socket is missing.
>>
>> I can reproduce it like this:
>>
>> $ cat /tmp/t.conf
>> (register-services
>>  (make <service>
>>    #:provides '(mytest)
>>    #:start (lambda args
>>              (system "touch /tmp/somefile")
>>              #t)))
>>
>> (start 'mytest)
>> $ shepherd -I -c/tmp/t.conf -s /tmp/sock
>> Starting service root...
>> Service root started.
>> Service root running with value #t.
>> Service root has been started.
>> Starting service mytest...
>>   C-c C-z
>> [1]+  Stopped                 shepherd -I -c/tmp/t.conf -s /tmp/sock
>> $ bg
>> [1]+ shepherd -I -c/tmp/t.conf -s /tmp/sock &
>> $ herd -s /tmp/sock status
>> herd: error: /tmp/sock: Connection refused
>>
>> This is both with 0.10.1 and with
>> d5ed516e736ce473902cc86b5cf4f61f27ebb642.
>
>Sorry, the bug is reproducible with 0.10.1 but *not* with
>d5ed516e736ce473902cc86b5cf4f61f27ebb642.
>
>I believe this was fixed by Shepherd commit
>2b310bd3b0ba0d7a08c77b456d34369cd6444edb (that is, after 0.10.1).
>
>I think I’ll release 0.10.2 within a couple of weeks, but it would be
>great if you could confirm that current Shepherd ‘master’ works for you.
>
>Thanks!
>
>Ludo’.
>

Sincerely.

-- 

Bernard 






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