Bug#754218: boot hangs forever on LSB job "raise network interfaces"

[Michael Biebl]

Am 08.07.2014 22:50, schrieb Stefano Zacchiroli:
> Now the questions/comments:
> 
> - I've had that script since ever, basically, and it used to work fine
>   in the past, both before and after switching to systemd as init. I'm
>   not sure why/when it stopped working.
> 
> - As a mere user, the above script is perfectly reasonable, I *do* want
>   to restart my firewall every time my network interface is brought up,
>   and AFAICT I'm using the right "API" to do so.

I had a look at the shorewall(6) init script. It has

# Required-Start:    $network $remote_fs


Now, $network is provided by the networking init script. As long as this
init script is not fully started, $network (or network.target) is not
yet available.

You've started shorewall as part of the if-up up, when $network is not
yet available, thus there is a dead lock.

So, it's actually exactly the same problem as with the NFS hook.


sysvinit doesn't bother, as it doesn't consider such dynamic
dependencies during runtime whereas systemd does.

What has changed is, that systemd_204-9 gained support for LSB system
facilities, i.e. now it understands that /etc/init.d/networking provides
$network.

This is most likely the reason you didn't see it in the past.

So, what to do about this: I'd say it's a bug to (re)start a SysV init
script from an if-up.d hook without actually checking if the service is
actually already runnig.
Because you simply disregard any dependencies which have been specified
in the LSB header.

It's problematic in general to (re)start SysV init scripts from any hook
(if-up.d, dhcp etc), since you can't ensure at that point that its
dependencies are actually all available.

I personally would consider this a local (mis)configuration which simply
didn't show up with sysvinit which only computes dependencies at install
time and only between init scripts in /etc/rc?.d/



-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

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