Bug#770633: systemd: Suggestion for a method to handle multiple providers of the same service

[Didier Roche]

Le 22/11/2014 21:25, Andrei POPESCU a écrit :
> Package: systemd
> Version: 215-6
> Severity: wishlist
> Tags: upstream
>
> Hello,
>
> I think systemd needs a method to deal with multiple providers of the
> same service that under usual circumstances (i.e. default configuration)
> can't run at the same time, e.g. display managers.
>
> Here's what I came up with, as possible addition to systemd.unit(5)
>
> -----------------------------------------------------------------------
>
> [INSTALL] SECTION OPTIONS
> ....
> AlternativeFor=
> The name of a service this unit provides, of which there might be
> several providers that can't (under normal circumstances) run at the
> same time. At installation time systemctl enable will only create
> symlinks from this name to the unit filename, with the same suffix as
> this unit.
>
> This option implies a Conflicts= against all other providers of the same
> service.
>
> -----------------------------------------------------------------------
>
> I think this would be quite simple to implement and is generic enough to
> be used for all kinds of services.

Hey,

See my answer on bug #764607, I think the Alias permits us to achieve 
this, in a same way we have alternatives. Then, it requires that the 
target Wants=<this alternative> though.

Cheers,
Didier