[Libguestfs] [PATCH] check for grub/menu.lst too

[Matthew Booth]

On 23/02/10 19:42, Guido Günther wrote:
>>From d30b4946f017ff8bde9d4ff62f93c418a707d9e8 Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Guido=20G=C3=BCnther?= <agx at sigxcpu.org>
> Date: Tue, 23 Feb 2010 19:50:40 +0100
> Subject: [PATCH] Check for grub/menu.lst if /etc/grub.conf can't be found

In virt-v2v, I actually don't bother looking for /etc/grub.conf, and
always use /boot/grub/menu.lst because it's symlinked on Red Hat systems.

> ---
>  perl/lib/Sys/Guestfs/Lib.pm |   10 ++++++++--
>  1 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/perl/lib/Sys/Guestfs/Lib.pm b/perl/lib/Sys/Guestfs/Lib.pm
> index e17728d..2864bfa 100644
> --- a/perl/lib/Sys/Guestfs/Lib.pm
> +++ b/perl/lib/Sys/Guestfs/Lib.pm
> @@ -1525,6 +1525,12 @@ sub _check_for_kernels
>          # For every kernel we find, inspect it and add to $os->{kernels}
>  
>          my $grub = _find_grub_prefix($g, $os);
> +        my $grub_conf = "/etc/grub.conf";
> +
> +        # Debian and other's have no /etc/grub.conf:
> +        if ( ! -f "$grub_conf" ) {
> +            $grub_conf = "$grub/grub/menu.lst";
> +        }
>  
>          my @boot_configs;
>  
> @@ -1544,7 +1550,7 @@ sub _check_for_kernels
>          my @configs = ();
>          # Get all configurations from grub
>          foreach my $bootable
> -            ($g->aug_match("/files/etc/grub.conf/title"))
> +            ($g->aug_match("/files/$grub_conf/title"))
>          {
>              my %config = ();
>              $config{title} = $g->aug_get($bootable);
> @@ -1617,7 +1623,7 @@ sub _check_for_kernels
>  
>          # Add the default configuration
>          eval {
> -            $boot{default} = $g->aug_get("/files/etc/grub.conf/default");
> +            $boot{default} = $g->aug_get("/files/$grub_conf/default");

Not convinced the above will work reliably, because augeas (at least not
as distributed by Fedora) doesn't load menu.lst by default. Have a look
here for how I did this in virt-v2v:

http://git.fedoraproject.org/git/virt-v2v.git?p=virt-v2v.git;a=blob;f=lib/Sys/VirtV2V/GuestOS/RedHat.pm;h=3f5d90a323ef332ea9d1f1772873263130eb6f22;hb=HEAD#l224

If Debian change the grub config in augeas to load menu.lst instead of
grub.conf, this would mean that a Fedora machine would only be able to
find kernels on Fedora guests, and a Debian machine would only be able
to find kernels on a Debian guest.

Matt
-- 
Matthew Booth, RHCA, RHCSS
Red Hat Engineering, Virtualisation Team

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