On Thu, Oct 28, 2010 at 01:52:24PM +0100, Matthew Booth wrote:
On 28/10/10 12:37, Richard W.M. Jones wrote:
>>From 6e19d032d0d28e62f38223b6cc05dc36d9352add Mon Sep 17 00:00:00 2001
>From: Richard W.M. Jones<rjones(a)redhat.com>
>Date: Wed, 27 Oct 2010 16:06:11 +0100
>Subject: [PATCH 3/4] tools: Use C API for inspection (RHBZ#642930).
>
>Update the following tools to use the C API for inspection:
>
> - virt-cat
> - virt-edit
> - virt-ls
> - virt-tar
> - virt-win-reg
>
>None of the tools in the tools/ directory now use the deprecated
>Perl inspection APIs.
>---
> tools/virt-cat | 37 +++++++++++++++++--------------------
> tools/virt-edit | 35 ++++++++++++++++-------------------
> tools/virt-ls | 39 ++++++++++++++++++---------------------
> tools/virt-tar | 38 ++++++++++++++++++--------------------
> tools/virt-win-reg | 39 ++++++++++++++++++---------------------
> 5 files changed, 87 insertions(+), 101 deletions(-)
>
>diff --git a/tools/virt-cat b/tools/virt-cat
>index 66806a1..546e85c 100755
>--- a/tools/virt-cat
>+++ b/tools/virt-cat
>@@ -157,22 +156,20 @@ if ($uri) {
>
> $g->launch ();
>
>-# List of possible filesystems.
>-my @partitions = get_partitions ($g);
>-
>-# Now query each one to build up a picture of what's in it.
>-my %fses =
>- inspect_all_partitions ($g, \@partitions,
>- use_windows_registry => 0);
>-
>-my $oses = inspect_operating_systems ($g, \%fses);
>-
>-my @roots = keys %$oses;
>-die __"multiboot operating systems are not supported by virt-cat" if
@roots> 1;
>-my $root_dev = $roots[0];
>-
>-my $os = $oses->{$root_dev};
>-mount_operating_system ($g, $os);
>+my @roots = $g->inspect_os ();
>+if (@roots == 0) {
>+ die __x("{prog}: No operating system could be detected inside this disk
image.\n\nThis may be because the file is not a disk image, or is not a virtual
machine\nimage, or because the OS type is not understood by libguestfs.\n\nIf you feel
this is an error, please file a bug report including as much\ninformation about the disk
image as possible.\n",
>+ prog => basename ($0));
>+}
>+if (@roots> 1) {
>+ die __x("{prog}: multiboot operating systems are not supported.\n",
>+ prog => basename ($0))
>+}
>+my %fses = $g->inspect_get_mountpoints ($roots[0]);
>+my @fses = sort { length $a<=> length $b } keys %fses;
>+foreach (@fses) {
>+ $g->mount_ro ($fses{$_}, $_);
>+}
>
> # Allow this to fail in case eg. the file does not exist.
> #
NB:https://bugzilla.redhat.com/show_bug.cgi?id=501888
This is pretty long for boiler plate code which will be used in all
the virt tools, including virt-v2v. This should live in a high-level
library function which:
1. Inspects a guest.
2. Mounts all its storage, optionally read-only.
That's how I did it first time, but:
It wouldn't necessarily need to form part of a published API
this is the problem. If it's in Sys::Guestfs::Lib it's pretty much
a published API.
Also the boilerplate isn't quite the same each time, particularly
w.r.t whether we allow multiple roots (virt-inspector) or require
writable mounts (eg. virt-edit).
I don't think there's a good answer here.
At least the error messages are the same so they only have to be
translated once.
Rich.
--
Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
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