systemd: please stop trying to take over the world :)

[Simo Sorce]

On Mon, 2011-06-13 at 19:02 +0200, Denys Vlasenko wrote:
> On Mon, 2011-06-13 at 12:37 -0400, Simo Sorce wrote:
> > On Mon, 2011-06-13 at 18:01 +0200, Denys Vlasenko wrote:
> > > > We invoke sethostname() from inside systemd since that is one of the
> > > > most trivial system calls known to men and doing this with a
> > > separate
> > > > binary is just absurd. This way we also can ensure that the hostname
> > > is
> > > > always initialised which is very useful for early boot logging and
> > > other
> > > > stuff. On systemd you get the guarantee that the hostname is always
> > > set
> > > > up if you run in userspace,
> > > 
> > > You can't possibly know what kind of (possibly dynamic) hostname
> > > admin might want to assign to his machine. The static hostname
> > > may be as useless as default "(none)" which is set by kernel.
> > > Anyway, logging with default hostname is not a catastrophe.
> > > 
> > > Why do you set up stuff no one asked you to?
> > 
> > Changing a machine hostname at random times is just asking for trouble.
> 
> I just tried it. So far flames don't shoot out of my notebook.
> 
> 
> > What's the problem of having a specific hostname set up at boot time?
> 
> The problem with having specific hostname I had is when I boot many
> dozens of diskless machines off the very same network filesystem,
> I definitely DONT want them to use the same hostname.

But until you can get "the real one" you basically are.

> One method I saw in use in real world in this situation is to assign
> hostnames by looking up (MAC_address,hostname) pairs in a database (say,
> a config file), and then set the found hostname. Of course, this is not
> possible until said database is available over network.

In this case you are not better/worse than before, once the network will
come up you'll add a script to change the hostname.
Setting it earlier in systemd makes no difference.

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York