Libguestfs - Aug 2014 - Using virt-sysprep and virt-customize with LXC containers: is it possible?

I'm setting up a system to run LXC containers with ZFS on Linux (Ubuntu
14.04). I intend to set up a base image which I'd like to clone to create
other containers from. virt-sysprep and virt-customize seem ideal for the
task: I obviously could mount and work with the rootfs from each container
directly, but the libguestfs tools have a bunch of pre-existing recipes
that would surely be much better than what I'd come up with on my own.

Unfortunately, I can't seem to find any way to tell the tools to work
directly on an already mounted directory (from a ZFS subvolume) instead of
a disk image.

Am I missing something or is this currently not possible?

Thanks in advance,
Daniel Miranda

On Tue, Aug 19, 2014 at 01:11:02PM -0300, Daniel Miranda
wrote:
> I'm setting up a system to run LXC containers with ZFS on Linux (Ubuntu
> 14.04). I intend to set up a base image which I'd like to clone to
create
> other containers from. virt-sysprep and virt-customize seem ideal for the
> task: I obviously could mount and work with the rootfs from each container
> directly, but the libguestfs tools have a bunch of pre-existing recipes
> that would surely be much better than what I'd come up with on my own.
> 
> Unfortunately, I can't seem to find any way to tell the tools to work
> directly on an already mounted directory (from a ZFS subvolume) instead of
> a disk image.
> 
> Am I missing something or is this currently not possible?
This was actually a feature of the original virt-sysprep (1.14).
However we removed it in a more recent version (1.16 IIRC).  So no,
virt-sysprep etc only work on disk images, not on mounted filesystems.

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/

That's unfortunate. Is there any particular reason it was removed? I think
having a 'directory' format, or even a 'mount' one where
libguestfs handles
mounting/unmounting would be nice.

Thanks for the help nevertheless,
Daniel


On Tue, Aug 19, 2014 at 3:08 PM, Richard W.M. Jones <rjones@redhat.com>
wrote:
> On Tue, Aug 19, 2014 at 01:11:02PM -0300, Daniel Miranda wrote:
> > I'm setting up a system to run LXC containers with ZFS on Linux
(Ubuntu
> > 14.04). I intend to set up a base image which I'd like to clone to
create
> > other containers from. virt-sysprep and virt-customize seem ideal for
the
> > task: I obviously could mount and work with the rootfs from each
> container
> > directly, but the libguestfs tools have a bunch of pre-existing
recipes
> > that would surely be much better than what I'd come up with on my
own.
> >
> > Unfortunately, I can't seem to find any way to tell the tools to
work
> > directly on an already mounted directory (from a ZFS subvolume)
instead
> of
> > a disk image.
> >
> > Am I missing something or is this currently not possible?
>
> This was actually a feature of the original virt-sysprep (1.14).
> However we removed it in a more recent version (1.16 IIRC).  So no,
> virt-sysprep etc only work on disk images, not on mounted filesystems.
>
> 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/
>