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xen-tools.xen-tools/bin/xen-update-image
steve 74a795d94b 2006-10-12 23:08:21 by steve
Update version number for v2.7 release.
2006-10-12 23:08:21 +00:00

431 lines
8.6 KiB
Perl
Executable File

#!/usr/bin/perl -w
=head1 NAME
xen-update-image - Update the software installed upon offline Xen images.
=head1 SYNOPSIS
xen-update-image [options] imageName1 imageName2 .. imageNameN
Help Options:
--help Show this scripts help information.
--manual Read this scripts manual.
--version Show the version number and exit.
General Options:
--dir Specify the directory which contains the image(s).
--lvm Specify the LVM volume group which contains the image(s).
--evms Specify the EVMS container which contains the image(s).
=cut
=head1 OPTIONS
=over 8
=item B<--dir>
Specify the directory which contains the image(s).
=item B<--help>
Show the script help.
=item B<--manual>
Read the manual.
=item B<--version>
Show the version number and exit.
=item B<--lvm>
Specify the LVM volume group which contains the image(s).
=item B<--evms>
Specify the EVMS container which contains the image(s).
=back
=cut
=head1 DESCRIPTION
xen-update-image is a simple script which allows you to update
a Xen image of Debian which has been created with xen-create-image.
It does this by mounting the image inside a temporary directory
then running:
apt-get update
apt-get upgrade
B<NOTE> If the image is already running within Xen this will cause corruption
otherwise it will allow you to update your image without booting it.
=cut
=head1 EXAMPLES
The following assumes there are two images which are not currently
running. The images are called 'test.my.flat', and 'x11.my.flat'.
Updating both images can be accomplished by executing:
xen-update-images --dir=/home/xen test.my.flat x11.my.flat
=cut
=head1 AUTHOR
Steve
--
http://www.steve.org.uk/
$Id: xen-update-image,v 1.14 2006-10-12 23:08:21 steve Exp $
=cut
=head1 LICENSE
Copyright (c) 2005-2006 by Steve Kemp. All rights reserved.
This module is free software;
you can redistribute it and/or modify it under
the same terms as Perl itself.
The LICENSE file contains the full text of the license.
=cut
use strict;
use English;
use File::Temp qw/ tempdir /;
use Getopt::Long;
use Pod::Usage;
#
# Configuration options, initially read from the configuration file
# but may be overridden by the command line.
#
# Command line flags *always* take precedence over the configuration file.
#
my %CONFIG;
#
# Release number.
#
my $RELEASE = '2.7';
#
# Read configuration file if it exists.
#
if ( -e "/etc/xen-tools/xen-tools.conf" )
{
readConfigurationFile( "/etc/xen-tools/xen-tools.conf" );
}
#
# Parse command line arguments, these override the values from the
# configuration file.
#
parseCommandLineArguments();
#
# Test that our arguments are sane.
#
checkArguments();
#
# Abort if non-root user.
#
if ( $EFFECTIVE_USER_ID != 0 )
{
print <<E_O_ROOT;
This script is not running with root privileges.
root privileges are required to successfully mount the disk image(s).
E_O_ROOT
exit;
}
#
# Loop over the supplied arguments, and attempt to update each image.
#
while( my $name = shift )
{
updateXenImage( $name );
}
#
# All done.
#
exit;
=begin doc
Mount the primary disk image, so that we're ready to update it.
=end doc
=cut
sub updateXenImage
{
my ( $name ) = ( @_ );
#
# Create a temporary directory, and prepare to mount the
# image there.
#
my $tmp = tempdir( CLEANUP => 1 );
my $img = '';
#
# If we're dealing with loopback images find the main one,
# and mount it.
#
if ( $CONFIG{'dir'} )
{
# The loopback image.
$img = $CONFIG{'dir'} . "/domains/" . $name . "/disk.img";
if ( ! -e $img )
{
print "Disk image '$img' for host '$name' not found\n";
return;
}
}
elsif ( $CONFIG{'lvm'} )
{
# The LVM volume
$img = "/dev/" . $CONFIG{'lvm'} . "/$name-disk";
# make sure it exists.
if ( ! -e $img )
{
print "Logical volume '$img' for host '$name' not found\n";
return;
}
}
elsif ( $CONFIG{'evms'} )
{
# The EVMS volume -- note, unlike LVM, you don't need the $CONFIG{'evms'}
# to see it and mount the volume. $CONFIG{'evms'} is only used for manipulating
# the underlying object. Still, I don't want to mess with the parse code and
# make it confusing - otherwise --evms takes an argument everywhere but here,
# which will confuse users. The better solution is to make it so that --evms can
# take a following container, but doesn't require it. For the moment, it is
# better to leave it as it is, take a container, and then ignore it.
# The best way to do it is to just read it out of the configuration file,
# tell the user what you got and where you got it from, and not bother the user
# with picking --dir or --lvm or --evms at all, but infer it from the config
# file's disk = parameter. xen-delete-image might work the same way, but
# it could be *slightly* more dangerous in the context of deleting.
$img = "/dev/evms/$name-disk";
# make sure it exists.
if ( ! -e $img )
{
print "EVMS volume '$img' for host '$name' not found\n";
return;
}
}
else
{
die "Can't happen?\n";
}
#
# Mount the image.
#
my $mount_cmd = "mount -t auto -o loop $img $tmp";
`$mount_cmd`;
#
# Make sure this is a Debian image.
#
if ( ( -e $tmp . "/usr/bin/apt-get" ) &&
( -e $tmp . "/etc/apt/sources.list" ) )
{
#
# Now run the update command.
#
system( "chroot $tmp /usr/bin/apt-get update" );
#
# Now upgrade
#
system( "DEBIAN_FRONTEND=noninteractive chroot $tmp /usr/bin/apt-get upgrade --yes --force-yes" );
}
else
{
print "Xen image $name is not a Debian GNU/Linux image. Skipping\n";
}
#
# Unmount
#
`umount $tmp`;
}
=begin doc
Read the configuration file specified.
=end doc
=cut
sub readConfigurationFile
{
my ($file) = ( @_ );
open( FILE, "<", $file ) or die "Cannot read file '$file' - $!";
my $line = "";
while (defined($line = <FILE>) )
{
chomp $line;
if ($line =~ s/\\$//)
{
$line .= <FILE>;
redo unless eof(FILE);
}
# Skip lines beginning with comments
next if ( $line =~ /^([ \t]*)\#/ );
# Skip blank lines
next if ( length( $line ) < 1 );
# Strip trailing comments.
if ( $line =~ /(.*)\#(.*)/ )
{
$line = $1;
}
# Find variable settings
if ( $line =~ /([^=]+)=([^\n]+)/ )
{
my $key = $1;
my $val = $2;
# Strip leading and trailing whitespace.
$key =~ s/^\s+//;
$key =~ s/\s+$//;
$val =~ s/^\s+//;
$val =~ s/\s+$//;
# Store value.
$CONFIG{ $key } = $val;
}
}
close( FILE );
}
=begin doc
Parse the arguments specified upon the command line.
=end doc
=cut
sub parseCommandLineArguments
{
my $HELP = 0;
my $MANUAL = 0;
my $VERSION = 0;
# Parse options.
#
GetOptions(
"dir=s", \$CONFIG{'dir'},
"lvm=s", \$CONFIG{'lvm'},
"evms=s", \$CONFIG{'evms'},
"help", \$HELP,
"manual", \$MANUAL,
"version", \$VERSION
);
pod2usage(1) if $HELP;
pod2usage(-verbose => 2 ) if $MANUAL;
if ( $VERSION )
{
my $REVISION = '$Revision: 1.14 $';
if ( $REVISION =~ /1.([0-9.]+) / )
{
$REVISION = $1;
}
print "xen-update-image release $RELEASE - CVS: $REVISION\n";
exit;
}
}
=begin doc
Test that the options we received from the command line, or our
configuration file, make sense.
=end doc
=cut
sub checkArguments
{
#
# Make sure we have either a volume, or a root.
#
if ( ( $CONFIG{'lvm'} && $CONFIG{'dir'} ) || ( $CONFIG{'lvm'} && $CONFIG{'evms'} ) || ( $CONFIG{'evms'} && $CONFIG{'dir'} ) )
{
print "Please use only one of: a volume group, an EVMS container, or a directory name\n";
exit;
}
#
# Make sure we have at least one of the lvm or root specified.
#
if ( (!defined( $CONFIG{'dir'} ) ) && ( !defined( $CONFIG{'lvm'} ) ) && ( !defined( $CONFIG{'evms'} ) ) )
{
print "Please specify either a directory root, an LVM volume group, or an EVMS container\n";
exit;
}
}