Libguestfs - Jul 2016 - IRC question about virt-builder ubuntu-* images

22:06 < adam12> rwmjones: If you're still around, just curious - any
reason why the ubuntu14 image doesn't come with `dpkg-reconfigure
openssh-server`
                already configured for firstboot?

The reason is because I couldn't work out how to automate this in the
preseed script.  If you want to have a go, then see:

https://github.com/libguestfs/libguestfs/blob/master/builder/website/ubuntu.sh
https://github.com/libguestfs/libguestfs/blob/master/builder/website/ubuntu.preseed

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/

On Sat, Jul 09, 2016 at 08:20:27AM +0100, Richard W.M. Jones
wrote:
> 
> 22:06 < adam12> rwmjones: If you're still around, just curious -
any reason why the ubuntu14 image doesn't come with `dpkg-reconfigure
openssh-server`
>                 already configured for firstboot?
> 
> The reason is because I couldn't work out how to automate this in the
> preseed script.  If you want to have a go, then see:
> 
>
https://github.com/libguestfs/libguestfs/blob/master/builder/website/ubuntu.sh
>
https://github.com/libguestfs/libguestfs/blob/master/builder/website/ubuntu.preseed
s.th. like

d-i preseed/late_command string \
   in-target dpkg-reconfigure openssh-server;

If you need special vealues before hand there's debconf-set-selection

Cheers,
 -- Guido
> 
> Rich.
> 
> -- 
> Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
> Read my programming and virtualization blog: http://rwmj.wordpress.com
> virt-df lists disk usage of guests without needing to install any
> software inside the virtual machine.  Supports Linux and Windows.
> http://people.redhat.com/~rjones/virt-df/
> 
> _______________________________________________
> Libguestfs mailing list
> Libguestfs@redhat.com
> https://www.redhat.com/mailman/listinfo/libguestfs
>

On Tue, Jul 12, 2016 at 07:40:51PM +0200, Guido Günther
wrote:
> On Sat, Jul 09, 2016 at 08:20:27AM +0100, Richard W.M. Jones wrote:
> > 
> > 22:06 < adam12> rwmjones: If you're still around, just
curious - any reason why the ubuntu14 image doesn't come with
`dpkg-reconfigure openssh-server`
> >                 already configured for firstboot?
> > 
> > The reason is because I couldn't work out how to automate this in
the
> > preseed script.  If you want to have a go, then see:
> > 
> >
https://github.com/libguestfs/libguestfs/blob/master/builder/website/ubuntu.sh
> >
https://github.com/libguestfs/libguestfs/blob/master/builder/website/ubuntu.preseed
> 
> s.th. like
> 
> d-i preseed/late_command string \
>    in-target dpkg-reconfigure openssh-server;
> 
> If you need special vealues before hand there's debconf-set-selection
Thanks Guido (.. and long time, no see :-) I guess you noticed we are
using your example for preseeding Debian images which was very helpful.

The above preseed command works to run 'dpkg-reconfigure
openssh-server'.
I tested this by adding it to the debian.preseed file, recreating the
debian-8 image and testing it again.

Unfortunately that command creates SSH host keys in the template,
which is not a good thing since virt-builder will duplicate the
template multiple times and each copy will share the same key.

But luckily we also run virt-sysprep on the template after creating it
which deletes those host keys:
http://libguestfs.org/virt-sysprep.1.html#ssh-hostkeys
That resolves the above problem.

But unluckily the Debian openssh package doesn't automatically
recreate host keys when it starts up, as Fedora does, see the several
sshd*.{service,target} files here:
http://pkgs.fedoraproject.org/cgit/rpms/openssh.git/tree/

I think this is a bug or missing functionality in the Debian openssh
package.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW