systemd clarification

[Bruno Cornec]

Sorry Mike, I can't really comment on the OpenBMC side, as I'm more a reader here than a contriutor myself. Someone else more accustomed to that will surely give you an answer.

Best regards,
Bruno.

Mike Jones said on Tue, Aug 25, 2020 at 12:03:23PM -0600:

>Bruno,
>
>A related question.
>
>When I look through the services and targets installed when including meta-phosphor, power on/off seems to lead to dead ends, meaning no exe to do the work.
>
>So I looked at meta-facebook, and it adds host-poweron.service, which calls exec power-util…
>
>So it seems to me that meta-phosphor only puts in the infrastructure, and a particular use/design requires adding services to do the actual work of power on/off. This seems logical wrt factoring out behaviors. Is this correct?
>
>This would mean in my cause of use meta-raspberrypi, I need to add the missing pieces if I want power control of my externally connected regulators to get powered on/off.
>
>Mike
>
>> On Aug 25, 2020, at 10:52 AM, Bruno Cornec <Bruno.Cornec at hpe.com> wrote:
>>
>> Hello,
>>
>> /etc/systemd is used to override or add locally units which are not delivered as part of the std systemd delivery which is under /lib/systemd (or /usr/lib/systemd depending on Linux distribuions). It's an easy way to modify a std unit file and change say the options used to start the daemon e.g.
>> So:
>>
>> Mike Jones said on Tue, Aug 25, 2020 at 10:20:54AM -0600:
>>> The lib path is not a search path in the systemd documentation, and the etc path has links into the lib path. So I assume services in the lib path are only run if they are linked into the etc path. Is this correct?
>>
>> No. they are run if they are enabled (systemctl list-units to see that)
>>
>>> If there is a an After= that lists something found only in the lib path, I assume it will run because After is not strong enough to prevent start. But if it was Requires=, then I assume it cannot start unless it is linked into the etc path so that it is available. Is this correct?
>>
>> No. No link is necessary.
>> Best regards,
>> Bruno.
>> --
>> HPE WW FLOSS Technology Strategist      http://www.hpe.com/engage/opensource
>> Open Source Profession, WW Linux Community Lead    http://github.com/bcornec
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-- 
HPE WW FLOSS Technology Strategist      http://www.hpe.com/engage/opensource
Open Source Profession, WW Linux Community Lead    http://github.com/bcornec
FLOSS projects:     http://mondorescue.org        http://project-builder.org
Musique ancienne?   http://www.musique-ancienne.org  http://www.medieval.org