[systemd-devel] multi-user.target only wants network.service if I'm doing 'systemct show runlevel3.target'

[Francis Moreau]

On 12/10/2014 10:19 AM, Francis Moreau wrote:
> Hello,
> 
> On 12/10/2014 07:23 AM, Ivan Shapovalov wrote:
>> On Tuesday 09 December 2014 at 17:25:48, Francis Moreau wrote:	
>>> Hello Lennart,
>>>
>>> Thanks for answering !
>>>
>>> On 12/09/2014 02:10 PM, Lennart Poettering wrote:
>>>> On Tue, 09.12.14 11:19, Francis Moreau (francis.moro at gmail.com) wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> I've a very weird behaviour with systemd 217:
>>>>>
>>>>> # systemctl show -p Wants multi-user.target | grep network.service
>>>>> # systemctl show -p Wants runlevel3.target | grep network.service
>>>>> Wants= ... network.service ...
>>>>> # systemctl show -p Wants multi-user.target | grep network.service
>>>>> Wants=... network.service ...
>>>>>
>>>>> So basically the network.service is not part of the multi-user target
>>>>> dependencies. But if I'm showing the state of the runlevel3 target, the
>>>>> network service magically becomes a dep of multi-user.target.
>>>>>
>>>>> The network.service is an sysv service which is started by rc[345].d and
>>>>> has in its LSB:
>>>>>
>>>>> Provide: $network
>>>>>
>>>>> Could anybody clarify what I'm facing ?
>>>>
>>>> systemd lazy loads services from the file system as they are
>>>> referenced. This includes symlinked aliases, which are only loaded when
>>>> a unit is referenced by that specific name.
>>>>
>>>
>>> Sorry but I don't really understand.
>>>
>>> Do you mean that the network.service wasn't loaded although the
>>> runlevel3.target, which is an alias for multi-user target (default
>>> target) wants it ?
>>>
>>> I would be glad if you could enlight me because I'm confused.
>>
>> Apparently, network.service gets pulled in only via runlevel3.target, i. e.
>> there is a symlink of kind
>>
>> /{etc,usr/lib,run}/systemd/system/runlevel3.target.wants/network.service -> network.service
>>
>> That is, the Wants= dependency is generated for runlevel3.target only, not for
>> multi-user.target.
>>
>> And, because systemd loads units lazily, systemd does not know about runlevel3.target
>> (and its dependencies) before anything forces systemd to load that unit.
>>
>> After you issue `systemctl show runlevel3.target`, systemd loads that unit,
>> loads its dependencies and merges them to multi-user.target (because runlevel3.target
>> is an alias for multi-user.target).
> 
> That helps, thanks !
> 
> However that seems a bit weird to have a target with 'hidden'
> dependencies that can appears magically when poking another one, at
> least from my point of (user) view.
> 
> Was the lazy load mechanism integrated recently ? I'm asking because
> systemd 208 doesn't show the same behaviour.
> 
> What's the recommanded way to make sure that the Wants= dependencies
> generated for runlevel3 target get pplied as soon as possible to its
> alias target 'multi-user' ?
> 

Could anybody enlight me because I actually don't know how I'm supposed
to start all services that runlevel3 would start otherwise. Should I add
manually a "Wants=</etc/rd.d/rc3/S*>" dependency in the multi-user target ?

Thanks.