[Libguestfs] [PATCH v4 1/2] v2v: bootloaders: search grub config for all distributions

[Richard W.M. Jones]

On Wed, Nov 02, 2016 at 05:42:28PM +0100, Pino Toscano wrote:
> On Wednesday, 2 November 2016 15:01:08 CET Richard W.M. Jones wrote:
> > From: Pavel Butsykin <pbutsykin at virtuozzo.com>
> > 
> > This patch improves the search of grub config on EFI partition. This
> > means that the config will be found not only for rhel but also for
> > many other distributions.  Tests were performed on the following
> > distributions: centos, fedora, ubuntu, suse. In all cases, the config
> > path was /boot/efi/EFI/*distname*/grub.cfg
> > 
> > The main purpose of the patch is to improve support for converting of
> > vm with UEFI for most distributions. Unfortunately this patch does not
> > solve the problem for all distributions, for example Debian does not
> > store grub config on the EFI partition, therefore for such
> > distributions another solution is necessary.
> > 
> > Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
> > Signed-off-by: Richard W.M. Jones <rjones at redhat.com>
> > ---
> 
> Mostly LGTM (it was the approach I suggested, after all) -- just one
> note below.
> 
> >  (* Grub1 (AKA grub-legacy) representation. *)
> >  class bootloader_grub1 (g : G.guestfs) inspect grub_config =
> > +  let () =
> > +    if grub_config = "/boot/efi/EFI/redhat/grub.conf" then
> > +      g#aug_transform "grub" "/boot/efi/EFI/redhat/grub.conf" in
> 
> I guess this could be changed to be:
> 
>   if String.is_prefix grub_config "/boot/efi/EFI/" then
>     g#aug_transform "grub" grub_config
> 
> so even if we keep it around for a while, it will work fine also for
> other distros than RH-based.

The problem I found is that if the path is included in the Augeas lens
and this code is in libguestfs at the same time, then you get the
error noted before about:

  augeas failed to parse [path to grub.conf]:
   error "Lenses @Grub and grub.lns could be used to load this file"

I think we should just set Augeas 1.7.0 (released tomorrow) as the
minimum version for virt-v2v users, and then the problem largely goes
away.  I was also looking at whether it is possible to detect if the
file has a transform already using Augeas APIs.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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