On 29.09.2016 13:06, Daniel P. Berrange wrote:
On Thu, Sep 29, 2016 at 01:00:15PM +0300, Nikolay Shirokovskiy
wrote:
>
>
> On 29.09.2016 12:21, Jiri Denemark wrote:
>> On Thu, Sep 29, 2016 at 11:33:04 +0300, Nikolay Shirokovskiy wrote:
>>> Hi, all.
>>>
>>> In virtuozzo mgmt we do not use libvirt-guests service. First because
>>> we need do extra steps on domain start and second we want to decice
>>> whether to suspend or to shutdown a domain on per domain basis. Starting
>>> is not the problem but system shutdown is. As domain in systemd based
>>> systems is just another unit we need to set ordering dependency so
>>> that domain will not be killed before mgmt service as ba79e387 do for
>>> libvirt-guest service. So let's remove this hardcode. I see 2 options.
>>
>> I don't see hard dependency anywhere in libvirtd.service, it just says
>>
>> Before=libvirt-guests.service
>
> Nope, I meant this code from mentioned commit:
>
> @@ -243,8 +243,10 @@ int virSystemdCreateMachine(const char *name,
> iscontainer ? "container" : "vm",
> (unsigned int)pidleader,
> rootdir ? rootdir : "",
> - 1, "Slice", "s",
> - slicename) < 0)
> + 3,
> + "Slice", "s", slicename,
> + "After", "as", 1,
"libvirtd.service",
> + "Before", "as", 1,
"libvirt-guests.service") < 0)
>
> This makes domain a special kind of unit (scope) and sets its ordering dependency.
> You can't do this with libvirtd.service itself because its different unit.
IIUC, the problem is that you want to replace 'libvirt-guests.service'
with a different impl ?
The way systemd tends to deal with things that must be a configurable
choice in this way is to define a target, and sysadmins can then make
arbitrary services dependancies of that target.
eg, we'd set 'Before: virt-guest-shutdown.target', and then make
libvirt-guests.service be a part of that target by default. You can
then have ability to turn off libvirt-guest.service and put your
own custom thing inside virt-guest-shutdown.taget
Thanx!