[gentoo-user] Re: technical review of systemd

[Nicolas Sebrecht]

The 23/02/14, Canek Peláez Valdés wrote:

> >> networkd (again, netctl is the command-line front-end) is not for
> >> enterprise networks; on the contrary, is for the trivial cases. For
> >> example, in a little web server I administer I have:
> >>
> >> $ cat /etc/systemd/system/network.service
> >> [Unit]
> >> Description=Static network service
> >> After=local-fs.target
> >> Before=network.target
> >> Documentation=man:ifconfig(8)
> >> Documentation=man:route(8)
> >>
> >> [Service]
> >> Type=oneshot
> >> RemainAfterExit=yes
> >> ExecStart=/bin/ifconfig enp2s12 192.168.1.2 broadcast 192.168.1.255
> >> netmask 255.255.255.0 up
> >> ExecStart=/bin/route add default gw 192.168.1.1 enp2s12
> >>
> >> [Install]
> >> WantedBy=multi-user.target
> >>
> >> (Yeah, I know, I should switch to ip, I'm sorry, I haven't had the time
> >> yet).
> >>
> >> I'm going to get rid of this trivial network.service unit file when
> >> 209 (or better 210) hits Gentoo. Cases like this are the use-cases for
> >> networkd.
> >
> > what i don't understand is if you look at how openRC does it, it only
> > really cares about up/down events and the /etc/conf.d/net is very
> > comprehensive, in part because it passes everything to iproute2 to handle,
> > the only thing i can't do without an additional shell script is tc qdiscs.
> > i don't need or want a network manager, just need something that applies
> > confs on startup / stop of interfaces.  I'm a little surprised that there
> > isn't an iproute2 .service file
> >
> > reading through your example, in fact this is preferrable to me than using
> > a network manager but using iproute2.  I would rather you keep this
> > example in, and have this shown on the wiki or somewhere as this neatly
> > resolves my network concern.
>
> Mmmh. Maybe I wasn't clear; in your case, it seems that
> iproute2+OpenRC *is* your network manager.
>
> Perhaps at some point networkd will gain the ability to use iproute2
> (or even absorb it), but right now is only for tiny little setups.

The way systemd services handle network whatever "network manager" you
enable is the last thing preventing me from using systemd on servers.
Seting up manual advanced setups on systemd looks crappy (if even
possible with the provided tools) compared to OpenRC.

Notice that iproute2 is the default everywhere for long time, here.

The OpenRC comprehensive configuration set for network management is
actually what I would expect in systemd.

<...>

> Having a "network manager" doesn't necessarily means having a big
> monolithic thing that sets up your network. If you use some
> scripts+conf with iproute2 to set up your network, then *that's* your
> network manager.
>
> The point of networkd (if I understand correctly), is that if you
> *need* iproute2 (I don't have it installed in any of my machines), or
> highly dynamic non-trivial network configurations, then networkd will
> not be enough.
>
> And, by the way, someone make me notice that netctl is an Arch'ism,
> and that the command-line front-end for networkd is actually
> networkctl.

Yes, it was taken from Arch in order to allow better network support for
advanced configurations whitout requiring to write yet another tool.

The thing is that I would expect systemd to handle the whole thing on
its own (with the help of iproute2) so that services have nice
grain-level dependencies.

-- 
Nicolas Sebrecht