=encoding utf8

=begin comment

pod2man and pod2html have differing bugs which makes it hard to write
URLs here.  The only way which works for both sorts of output is to
just write the URL directly.  Do NOT use L<...> for URLs.

We break with tradition here and don't use ALL CAPS for the section
headings, as this makes them much easier to read.

=end comment

=head1 NAME

guestfs-recipes - libguestfs, guestfish and virt tools recipes

=head1 DESCRIPTION

This page contains recipes for and links to things you can do using
libguestfs, L<guestfish(1)> and the virt tools.

=head1 Audit a virtual machine for setuid files

The link below contains a small program which can be used to audit a
Linux virtual machine to see what setuid and setgid files it contains.

https://rwmj.wordpress.com/2010/12/15/tip-audit-virtual-machine-for-setuid-files/#content

=head1 Change the background image in a Windows XP VM

The links below explain how to use L<guestfish(1)> to change the
background image for a user of a Windows XP VM.  Unfortunately the
technique appears to be substantially different for each version of
Windows.

https://lists.fedoraproject.org/pipermail/virt/2011-May/002655.html
https://lists.fedoraproject.org/pipermail/virt/2011-May/002658.html

=head1 Cloning a virtual machine (Linux)

The guestfish technique described in the link below works well for
most Linux VMs.  Depending on the Linux distro you may need to change
the paths slightly.

https://rwmj.wordpress.com/2010/09/24/tip-my-procedure-for-cloning-a-fedora-vm/#content

Avoid L<virt-clone(1)>.  Currently what to do about virt-clone is
under discussion.

https://www.redhat.com/archives/virt-tools-list/2011-May/msg00019.html

=head1 Cloning a virtual machine (Windows)

It is possible to do a "sysprep" using libguestfs alone, although not
straightforward.  Currently there is code in the Aeolus Oz project
which does this (using libguestfs).  As part of our review of the
virt-clone tool, we may add sysprepping ability.

https://github.com/clalancette/oz
https://www.redhat.com/archives/virt-tools-list/2011-May/msg00019.html

=head1 Convert a CD-ROM / DVD / ISO to a tarball

This converts input C<cd.iso> to output C<cd.tar.gz>:

 guestfish --ro -a cd.iso -m /dev/sda tgz-out / cd.tar.gz

To export just a subdirectory, eg. C</files>, do:

 guestfish --ro -a cd.iso -m /dev/sda tgz-out /files cd.tar.gz

=head1 Create empty disk images

You can use the L<guestfish(1)> I<-N> option to create empty disk
images.  The useful guide below explains the options available.

https://rwmj.wordpress.com/2010/09/08/new-guestfish-n-options-in-1-5-9/#content

=head1 Dump raw filesystem content from inside a disk image or VM

You can use the L<guestfish(1)> C<download> command to extract the raw
filesystem content from any filesystem in a disk image or a VM (even
one which is encrypted or buried inside an LV):

 guestfish --ro -a disk.img run : download /dev/sda1 sda1.img

 guestfish --ro -d Guest run : download /dev/vg_guest/lv_root lv.img

To list the filesystems in a disk image, use L<virt-filesystems(1)>.

=head1 Edit grub configuration in a VM

You can use this to:

=over 4

=item *

Fix a virtual machine that does not boot.

=item *

Change which kernel is used to boot the VM.

=item *

Change kernel command line options.

=back

Use L<virt-edit(1)> to edit the grub configuration:

 virt-edit -d BrokenGuest /boot/grub/grub.conf

or for general tinkering inside an unbootable VM use L<virt-rescue(1)>
like this:

 virt-rescue -d BrokenGuest

=head1 Export any directory from a VM

To export C</home> from a VM into a local directory use
L<virt-copy-out(1)>:

 virt-copy-out -d Guest /home .

Notes:

=over 4

=item *

The final dot of the command is not a printing error.  It means we
want to copy out to the current directory.

=item *

This creates a directory called C<home> under the current directory.

=back

If the guest is a Windows guest then you can use drive letters and
backslashes, but you must prefix the path with C<win:> and quote it to
protect it from the shell, like this:

 virt-copy-out -d WinGuest 'win:c:\windows\system32\config' .

To get the output as a compressed tarball, do:

 virt-tar-out -d Guest /home - | gzip --best > home.tar.gz

Although it sounds tempting, this is usually not a reliable way to get
a backup from a running guest.  See the entry in the FAQ:
http://libguestfs.org/FAQ.html#backup

=head1 Find out which user is using the most space

This simple script examines a Linux guest to find out which user is
using the most space in their home directory:

 #!/bin/sh -
 
 set -e
 
 vm="$1"
 dir=/home
 
 eval $(guestfish --ro -d "$vm" -i --listen)
 
 for d in $(guestfish --remote ls "$dir"); do
     echo -n "$dir/$d"
     echo -ne '\t'
     guestfish --remote du "$dir/$d";
 done | sort -nr -k 2
 
 guestfish --remote exit

=head1 Get DHCP address from a VM

The link below explains the many different possible techniques for
getting the last assigned DHCP address of a virtual machine.

https://rwmj.wordpress.com/2011/03/31/tip-code-for-getting-dhcp-address-from-a-virtual-machine-disk-image/#content

In the libguestfs source examples directory you will find the latest
version of the C<virt-dhcp-address.c> program.

=head1 Get the operating system product name string

Save the following script into a file called C<product-name.sh>:

 #!/bin/sh -
 set -e
 eval "$(guestfish --ro -d "$1" --i --listen)"
 root="$(guestfish --remote inspect-get-roots)"
 guestfish --remote inspect-get-product-name "$root"
 guestfish --remote exit

Make the script executable and run it on a named guest:

 # product-name.sh RHEL60x64
 Red Hat Enterprise Linux Server release 6.0 (Santiago)

You can also use an XPath query on the L<virt-inspector(1)> XML using
the C<xpath> command line tool or from your favourite programming
language:

 # virt-inspector RHEL60x64 > xml
 # xpath '//product_name' < xml
 Found 1 nodes:
 -- NODE --
 <product_name>Red Hat Enterprise Linux Server release 6.0 (Santiago)</product_name>

=head1 Get the default boot kernel for a Linux VM

The link below contains a program to print the default boot kernel for
a Linux VM.

https://rwmj.wordpress.com/2010/10/30/tip-use-augeas-to-get-the-default-boot-kernel-for-a-vm/#content

It uses Augeas, and the technique is generally applicable for many
different tasks, such as:

=over 4

=item *

listing the user accounts in the guest

=item *

what repositories is it configured to use

=item *

what NTP servers does it connect to

=item *

what were the boot messages last time it booted

=item *

listing who was logged in recently

=back

http://augeas.net/

=head1 Install RPMs in a guest

The link below contains a method to install RPMs in a guest.  In fact
the RPMs are just uploaded to the guest along with a "firstboot"
script that installs them next time the guest is booted.  You could
use this technique to install vital security updates in an offline
guest.

https://rwmj.wordpress.com/2010/12/01/tip-install-rpms-in-a-guest/#content

=head1 List applications installed in a VM

Save the following to a file C<list-apps.sh>:

 #!/bin/sh -
 set -e
 eval "$(guestfish --ro -d "$1" --i --listen)"
 root="$(guestfish --remote inspect-get-roots)"
 guestfish --remote inspect-list-applications "$root"
 guestfish --remote exit

Make the file executable and then you can run it on any named
virtual machine:

 # list-apps.sh WinGuest
 [0] = {
   app_name: Mozilla Firefox (3.6.12)
   app_display_name: Mozilla Firefox (3.6.12)
   app_epoch: 0
   app_version: 3.6.12 (en-GB)
   app_release:
   app_install_path: C:\Program Files\Mozilla Firefox
   app_trans_path:
   app_publisher: Mozilla
   app_url: http://www.mozilla.com/en-GB/
   app_source_package:
   app_summary:
   app_description: Mozilla Firefox
 }
 [1] = {
   app_name: VLC media player
   app_display_name: VLC media player 1.1.5
   app_epoch: 0
   app_version: 1.1.5
   app_release:
   app_install_path: C:\Program Files\VideoLAN\VLC
   app_trans_path:
   app_publisher: VideoLAN
   app_url: http://www.videolan.org/
   app_source_package:
   app_summary:
   app_description:
 }

If you want to run the script on disk images (instead of libvirt
virtual machines), change C<-d "$1"> to C<-a "$1">.  See also
L<virt-inspector(1)>.

=head1 List files and directories in a VM

This involves using the L<guestfish(1)> C<find0> command like this:

 guestfish --ro -d Guest -i find0 / - | tr '\0' '\n' | sort

=head1 List services in a Windows VM

The link below contains a script that can be used to list out the
services from a Windows VM, and whether those services run at boot
time or are loaded on demand.

https://rwmj.wordpress.com/2010/12/10/tip-list-services-in-a-windows-guest/#content

=head1 Make a disk image sparse

The link below contains some guides for making a disk image sparse (or
reintroducing sparseness).

https://rwmj.wordpress.com/2010/10/19/tip-making-a-disk-image-sparse/#content

=head1 Monitor disk usage over time

You can use L<virt-df(1)> to monitor disk usage of your guests over
time.  The link below contains a guide.

http://virt-tools.org/learning/advanced-virt-df/

=head1 Reading the Windows Event Log from Windows Vista (or later)

L<guestfish(1)> plus the tools described in the link below can be used
to read out the Windows Event Log from any virtual machine running
Windows Vista or a later version.

https://rwmj.wordpress.com/2011/04/17/decoding-the-windows-event-log-using-guestfish/#content

=head1 Remove root password (Linux)

Using the L<virt-edit(1)> I<-e> option you can do simple replacements
on files.  One use is to remove the root password from a Linux guest:

 virt-edit domname /etc/passwd -e 's/^root:.*?:/root::/'

=head1 Remove Administrator password (Windows)

The link below contains one technique for removing the Administrator
password from a Windows VM, or to be more precise, it gives you a
command prompt the next time you log in which you can use to bypass
any security:

https://mdbooth.wordpress.com/2010/10/18/resetting-a-windows-guests-administrator-password-with-guestfish/

=head1 Unpack a live CD

Linux live CDs often contain multiple layers of disk images wrapped
like a Russian doll.  You can use L<guestfish(1)> to look inside these
multiple layers, as outlined in the guide below.

https://rwmj.wordpress.com/2009/07/15/unpack-the-russian-doll-of-a-f11-live-cd/#content

=head1 Uploading and downloading files

The link below contains general tips on uploading (copying in)
and downloading (copying out) files from VMs.

https://rwmj.wordpress.com/2010/12/02/tip-uploading-and-downloading/#content

=head1 Use libguestfs tools on VMware ESX guests

The link below explains how to use libguestfs, L<guestfish(1)> and the
virt tools on any VMware ESX guests, by first sharing the VMware VMFS
over sshfs.

https://rwmj.wordpress.com/2011/05/10/tip-use-libguestfs-on-vmware-esx-guests/#content

=head1 SEE ALSO

L<guestfs(3)>,
L<guestfish(1)>,
L<guestfs-examples(3)>,
L<guestfs-erlang(3)>,
L<guestfs-java(3)>,
L<guestfs-ocaml(3)>,
L<guestfs-perl(3)>,
L<guestfs-python(3)>,
L<guestfs-ruby(3)>,
L<http://libguestfs.org/>.

=head1 AUTHORS

Richard W.M. Jones (C<rjones at redhat dot com>)

=head1 COPYRIGHT

Copyright (C) 2009-2012 Red Hat Inc. L<http://libguestfs.org/>

The examples in this manual page may be freely copied, modified and
distributed without any restrictions.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
