#!/usr/bin/perl -w

=head1 NAME

xt-customize-image - Customize a freshly installed copy of GNU/Linux

=cut

=head1 SYNOPSIS

  xt-customize-image [options]

  Help Options:
   --help     Show this scripts help information.
   --manual   Read this scripts manual.
   --version  Show the version number and exit.

  Debugging Options:
   --verbose  Be verbose in our execution.

  Mandatory Options:
   --location The location of the new installation
   --dist     The name of the distribution which has been installed.

  All other options from xen-create-image, such as the new IP address(es)
 to give to the new instance, will be passed as environmental variables.

=cut

=head1 NOTES

  This script is invoked by xen-create-image after it has created a
 fresh installation of Linux withing a temporary location.

  This script will be invoked with a full copy of the arguments from
 xen-create-image in its environment, along with several command line
 arguments.

  The command line arguments which are mandatory are:

   --location  - The temporary installation root of the new install
   --dist      - The distribution which has been installed.

=cut


=head1 HOOK SCRIPTS

  The distribution name is used to locate an appropriate collection
 of scripts, or hooks, to execute to do the actual customisation.

  The hooks will each be executed with a single parameter which is
 the directory path to the new instance.  This argument is taken from
 the --location option.

  For the distribution named 'foo' the scripts will be loaded and
 executed from '/usr/lib/xen-tools/foo.d'.  Each executable will
 be loaded and executed in sorted order.

=cut


=head1 AUTHORS

 Steve Kemp, http://www.steve.org.uk/
 Axel Beckert, http://noone.org/abe/
 Stéphane Jourdois

=cut


=head1 LICENSE

Copyright (c) 2005-2009 by Steve Kemp, (c) 2010 by The Xen-Tools
Development Team. 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 Env;
use Getopt::Long;
use Pod::Usage;


#
#  Configuration values read from the command line.
#
#  We do not need to read any configuration file.
#
my %CONFIG;

#
# Release number.
#
my $RELEASE = '4.4~dev';



#
#  Parse the command line arguments.
#
parseCommandLineArguments();


#
#  Check our arguments.
#
checkArguments();


#
#  Run each relevant hook scripts.
#
runDistributionHooks();


#
#  Exit cleanly - any errors which have already occurred will result
# in "exit 1".
#
exit 0;



=begin doc

  Parse the command line arguments this script was given.

=end doc

=cut

sub parseCommandLineArguments
{
    my $HELP    = 0;
    my $MANUAL  = 0;
    my $VERSION = 0;

    #
    #  Parse options.
    #
    GetOptions( "location=s", \$CONFIG{ 'location' },
                "dist=s",     \$CONFIG{ 'dist' },
                "verbose",    \$CONFIG{ 'verbose' },
                "help",       \$HELP,
                "manual",     \$MANUAL,
                "version",    \$VERSION
              );

    pod2usage(1) if $HELP;
    pod2usage( -verbose => 2 ) if $MANUAL;


    if ($VERSION)
    {
        print "xt-customize-image release $RELEASE\n";
        exit;
    }
}



=begin doc

  Test that the command line arguments we were given make sense.

=end doc

=cut

sub checkArguments
{

    #
    #  We require a location.
    #
    if ( !defined( $CONFIG{ 'location' } ) )
    {
        print "The '--location' argument is mandatory\n";
        exit 1;
    }


    #
    #  Test that the location we've been given exists
    #
    if ( !-d $CONFIG{ 'location' } )
    {
        print "The installation directory we've been given doesn't exist\n";
        print "We tried to use : $CONFIG{'location'}\n";
        exit 1;
    }


    #
    #  We require a distribution name.
    #
    if ( !defined( $CONFIG{ 'dist' } ) )
    {
        print "The '--dist' argument is mandatory\n";
        exit 1;
    }


    #
    #  Test that the distribution name we've been given
    # to configure has a collection of hook scripts.
    #
    #  If there are no scripts then we clearly cannot
    # customise it!
    #
    my $dir = "/usr/lib/xen-tools/" . $CONFIG{ 'dist' } . ".d";

    if ( !-d $dir )
    {
        print <<E_OR;

  We\'re trying to configure an installation of $CONFIG{'dist'} in
 $CONFIG{'location'} - but there is no hook directory for us to use.

  This means we don\'t know how to configure this installation.

  We\'d expect the hook directory to be : $dir

  Aborting.
E_OR
        exit 1;
    }

}



=begin doc

  This function does the real work of running each of our hook scripts.

  Each hook script is executed in turn, ignoring emacs save files and
 dpkg files.

  We will give each script the name of the directory containing the
 installation as a single argument.

=end doc

=cut

sub runDistributionHooks
{

    #
    #  Hook directory.
    #
    my $hooks = "/usr/lib/xen-tools/" . $CONFIG{ 'dist' } . ".d/";

    #
    #  Installation prefix
    #
    my $prefix = $CONFIG{ 'location' };

    #
    #  If we're running verbosely then setup the client environment
    # appropriately.
    #
    #  This is useful in case this script is called outwith the usual
    # xen-create-image framework.
    #
    if ( $CONFIG{ 'verbose' } )
    {
        $ENV{ 'verbose' } = 1;
    }

    #
    # Make sure that our scripts run in sorted order, as
    # the user would expect.
    #
    foreach my $file ( sort( glob( $hooks . "*" ) ) )
    {

        # skip files that end with .dpkg-new, .dpkg-old or '~'
        next if ( $file =~ /\.dpkg-(new|old)/ );
        next if ( $file =~ /~$/ );

        #
        # Only run executable files.
        #
        if ( ( -x $file ) && ( -f $file ) )
        {

            #
            # Just display the name - no need to see the full path.
            #
            my $name = $file;
            if ( $file =~ /(.*)\/(.*)/ )
            {
                $name = $2;
            }

            #
            # Complete command we're going to execute.
            #
            my $cmd = $hooks . $name . " $CONFIG{'location'}";

            #
            #  Run the command.  This has different prolog and epilog
            # depending on whether we're running verbosely or not.
            #
            if ( $CONFIG{ 'verbose' } )
            {
                print "Running hook $name ['$cmd']\n";
                print "--\n";
                my $rc = system($cmd);
                if ($rc != 0) {
                print "hook $name failed: $?\n";
                exit 1;
            }
                print "--\n";
                print "Done\n\n";
            }
            else
            {
                print "Running hook $name\n";
                my $rc = system($cmd);
                if ($rc != 0) {
                    print "hook $name failed: $?\n";
                    exit 1;
                }
                print "hook $name: done.\n";
            }
        }
    }
}