[Lxc-users] lxc-clone

[Serge Hallyn]

Hi Daniel,

Quoting Daniel Lezcano (daniel.lezcano at free.fr):
> >>>+echo "Tweaking configuration"
> >>>+cp $lxc_path/$lxc_orig/config $lxc_path/$lxc_new/config
> >>>+sed -i '/lxc.utsname/d' $lxc_path/$lxc_new/config
> >>>+echo "lxc.utsname = $hostname">>   $lxc_path/$lxc_new/config
> >>We should not assume lxc.utsname is in the configuration file in
> >>order to not write a hostname in all the cases.
> >>The user may want to let the container to setup itself the hostname.
> >What do you think is the best way to do this?  We could allow the user
> >to specify a 'firstboot' script, which gets copied into root directory
> >of the container.   Maybe boot the container when it's done, run
> >/firstboot.sh, and shut down.  Or just let that happen when the user
> >first boots.  We could use a /etc/init.d/lxc-firstboot script, but
> >that will only work if the container's init system actually looks at
> >sysvinit scripts.  Obviously sysvinit and upstart do, and I must
> >assume that systemd does.  lxc-init I assume doesn't.
> 
> Mmh, that's look a bit complicate for the user. I was thinking about
> something simpler like:
> 
> grep -q "lxc.utsname" $lxc_path/$lxc_new/config
> if [ $? == 0 ]; then
>     sed -e "s/lxc.utsname/lxc.utsname=$hostname" $lxc_path/$lxc_new/config
> else
>     echo "lxc.utsname = $hostname">> $lxc_path/$lxc_new/config
> fi

I started changing my code to this, but now am wondering how this
differs from what I was doing, which was:

sed -i '/lxc.utsname/d' $lxc_path/$lxc_new/config
echo "lxc.utsname = $hostname" >> $lxc_path/$lxc_new/config

The only difference is that in mine, if the original config had a
hostname at top of file, it'll now be at bottom of file.  But with
both your snippets and mine, the 'lxc.utsname = new_hostname' will
be the one and only utsname in the config.

If you still think it's worth changing I'll do so, but I like that
mine is shorter.

-serge