Re: [gentoo-user] Re: [~amd64] NFS server broken again :(

[Tom H <tomh0665@gmail.com>]

On Tue, Oct 28, 2014 at 9:50 PM, Rich Freeman <rich0@gentoo.org> wrote:
> On Tue, Oct 28, 2014 at 9:36 PM, Tom H <tomh0665@gmail.com> wrote:
>> Since Gentoo's rpcbind.service has "Wants=rpcbind.target" and
>> "Before=rpcbind.target"", having nfs-server.service depend on
>> rpcbind.target rather than rpcbind.service should work as long as
>> rpcbind.service is enabled.
>>
>> But having "Requires=rpcbind.service" and "After=rpcbind.service",
>> like nfsd.service has/had, means that you don't have to enable
>> rpcbind.service.
>
> I was just looking at that and thinking the same thing.  Nothing is
> really forcing rpcbind to load the way things are specified right now.
> If a service really requires another service to operate, it should say
> that.  There is no problem doing that via a target, but then the
> target still needs to pull it in.

Wouldn't the solution to this problem to have a news item to let the
user know that rpcbind was being started as a dependency of
nfsd.service but that it now needs to be enabled in order to be
started by nfs-server.service?


> There seems a general tendency in systemd to express dependencies as
> "after" instead of "requires."  That is fine if the service doesn't
> really require something else, but if there really is a true
> dependency then it just causes problems when somebody doesn't notice
> and fails to enable the other unit.

AFAIK they're completely different and you can have service1 have a
"Requires" on service2 but have service2 start before service1. So if
someone's using "After" and expecting "Requires", he/she is bound to
be surprised by the result.

Is "After" really necessary as an option? I've never come across a
service that uses "After" without a "Requires" or a Wants" but I've
never taken the time to look.