Handle various conditions and cleanup.

Added code to handle deletion of the default boot image.  This now
succeeds so long as the default boot image is not the running image.
The running image still can not be deleted.

Correctly handle case where image being deleted resides before the
default boot image in the grub config file.  Previously this would
either switch the default boot image to the one after it, or leave the
default pointing to a non-existant entry.

Added the Vyatta license.

Re-organized and added comments to make the code easier to maintain.

1 files changed, 247 insertions, 123 deletions

diff --git a/scripts/vyatta-boot-image.pl b/scripts/vyatta-boot-image.pl
index 8b8a19a..304f35c 100755
--- a/scripts/vyatta-boot-image.pl
+++ b/scripts/vyatta-boot-image.pl
@@ -1,20 +1,54 @@
 #!/usr/bin/perl
 
+# **** License ****
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program 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
+# General Public License for more details.
+#
+# This code was originally developed by Vyatta, Inc.
+# Portions created by Vyatta are Copyright (C) 2007 Vyatta, Inc.
+# All Rights Reserved.
+#
+# Author: An-Cheng Huang, Bob Gilligan
+# Date: January, 2010
+# Description: Script to manage system images.  Provides the ability to
+#	display status of images, select the default image to boot, and
+#	to delete images.
+#
+# **** End License ****
+
 use strict;
 use warnings;
 use Getopt::Long;
 use File::Temp qw/ :mktemp /;
 
+# 
+# Constants
+# 
 my $UNION_BOOT = '/live/image/boot';
 my $UNION_GRUB_CFG = "$UNION_BOOT/grub/grub.cfg";
 my $VER_FILE = '/opt/vyatta/etc/version';
 my $OLD_IMG_VER_STR = 'Old-non-image-installation';
 my $OLD_GRUB_CFG = '/boot/grub/grub.cfg';
 my $DISK_BOOT = '/boot';
-my $grub_cfg;
 
-# this function parses the grub config file and returns a hash reference
-# of the parsed data.
+# 
+# Globals
+# 
+my $grub_cfg;	# Pathname of grub config file we will use.
+
+# This function parses the grub config file and returns a hash array
+# of the parsed data.  There is one element of the array for each grub
+# config file entry.  Each element is a hash that contains:  The "index" of
+# entry in the grub config file, the "version" string of the entry, the
+# "terminal type" of the entry -- "kvm" or "serisl", and a flag indicating
+# whether the entry is a "lost password reset" boot menu item.
+#
 sub parseGrubCfg {
   my $fd = undef;
   return undef if (!open($fd, '<', $grub_cfg));
@@ -66,8 +100,10 @@ sub parseGrubCfg {
   return \%ghash;
 }
 
-# this function deletes the entries for the specified version from the grub
-# config file. returns undef if successful. otherwise returns error message.
+# This function deletes the entries for the specified version from the grub
+# config file. returns undef if successful. Otherwise it returns an 
+# error message.
+#
 sub deleteGrubEntries {
   my ($del_ver) = @_;
 
@@ -121,18 +157,17 @@ sub deleteGrubEntries {
   return undef;
 }
 
-# this function takes the default terminal type and a list of all entries
-# and returns the "boot list", i.e., the list for user to select which one
-# to boot.
+# This function takes the default terminal type and a list of all grub
+# config file entries as generated by parseGrubConfig() and returns
+# the "boot list".  This list contains one entry for each image
+# version.
+#
 sub getBootList {
-  my ($dver, $dterm, $entries, $delete) = @_;
+  my ($dterm, $entries) = @_;
   my %vhash = ();
   my @list = ();
   foreach (@{$entries}) {
     my ($ver, $term) = ($_->{'ver'}, $_->{'term'});
-    # don't list default entry if deleting
-    next if (defined($delete) && $ver eq $dver);
-
     next if ($_->{'reset'}); # skip password reset entry
     next if ($term ne $dterm); # not the default terminal
     next if (defined($vhash{$ver})); # version already in list
@@ -143,105 +178,39 @@ sub getBootList {
   return \@list;
 }
 
+# Prints the boot list generated by getBootList().
+#
 sub displayBootList {
   my ($didx, $entries) = @_;
+  my $running_ver = curVer();
   for my $i (0 .. $#{$entries}) {
     my $di = $i + 1; 
-    my $ver = ${$entries}[$i]->{'ver'};
+    my $ver = $ {$entries}[$i]->{'ver'};
     my $m = '';
-    if ($didx == ${$entries}[$i]->{'idx'}) {
+    if ($didx == $ {$entries}[$i]->{'idx'}) {
       $m = ' (default boot)';
     }
+    
+    if ($ver eq $running_ver) {
+	$m .= ' (running version)';
+    }
+
     printf "  %2d: %s%s\n", $di, $ver, $m;
   }
 }
 
-my ($show, $del, $sel) = (undef, undef, undef);
-GetOptions(
-  'show' => \$show,
-  'delete' => \$del,
-  'select' => \$sel
-);
-
-
-if (-e $UNION_GRUB_CFG) {
-    $grub_cfg = $UNION_GRUB_CFG;
-} elsif (-e $OLD_GRUB_CFG) {
-    $grub_cfg = $OLD_GRUB_CFG;
-} else {
-    print "Can not open Grub config file\n";
-    exit 1;
-}
-
-
-my $gref = parseGrubCfg();
-if (!defined($gref)) {
-  print "Cannot find GRUB configuration file. Exiting...\n";
-  exit 1;
-}
-my $def_idx = $gref->{'default'};
-my $entries = $gref->{'entries'};
-if (!defined($def_idx) || !defined($entries)
-    || !defined(${$entries}[$def_idx])) {
-  print "Error parsing GRUB configuration file. Exiting...\n";
-  exit 1;
-}
-my $def_ver = ${$entries}[$def_idx]->{'ver'};
-my $def_term = ${$entries}[$def_idx]->{'term'};
-
-my $bentries = getBootList($def_ver, $def_term, $entries, $del);
-if ($#{$bentries} < 0) {
-  print "No images found. Exiting...\n";
-  exit 1;
-}
-
-my $msg = 'The system currently has the following image(s) installed:';
-if (defined($del)) {
-  # doing delete
-  $msg = 'The following image(s) can be deleted:';
-}
-print "$msg\n\n";
-displayBootList($def_idx, $bentries);
-print "\n";
-
-exit 0 if (defined($show) || (!defined($sel) && !defined($del))); # show-only
-
-# for doing select
-my $prompt_msg = 'Select the default boot image: ';
-my $error_msg = 'Invalid selection. Default is not changed.';
-if ($del) {
-  # doing delete
-  $prompt_msg = 'Select the image to delete: ';
-  $error_msg = 'Invalid selection. Nothing is deleted.';
-}
-
-print "$prompt_msg";
-my $resp = <STDIN>;
-if (defined($resp)) {
-  chomp($resp);
-  if (!($resp =~ /^\d+$/) || ($resp < 1) || ($resp > ($#{$bentries} + 1))) {
-    $resp = undef;
+# Sets the grub config file default pointer to the boot list entry
+# number passed in.
+#
+sub doSelect {
+  my ($resp, $def_ver, $bentries) = @_;
+  my $new_idx = $ {$bentries}[$resp]->{'idx'};
+  my $new_ver = $ {$bentries}[$resp]->{'ver'};
+  if ($new_ver eq $def_ver) {
+      print "The default boot image has not been changed.\n";
+      exit 0;
   }
-}
-if (!defined($resp)) {
-  print "$error_msg Exiting...\n";
-  exit 1;
-}
-print "\n";
-
-$resp -= 1;
 
-if ($sel) {
-  doSelect($resp);
-} elsif ($del) {
-  doDelete($resp);
-}
-exit 0;
-
-sub doSelect {
-  my ($bdx) = @_;
-  my $new_idx = ${$bentries}[$resp]->{'idx'};
-  my $new_ver = ${$bentries}[$resp]->{'ver'};
   system("sed -i 's/^set default=.*\$/set default=$new_idx/' $grub_cfg");
   if ($? >> 8) {
     print "Failed to set the default boot image. Exiting...\n";
@@ -255,18 +224,71 @@ EOF
   exit 0;
 }
 
+# Set the grub default pointer to the entry whose name is passed in
+#
+sub select_by_name {
+    my ($new_def_ver, $def_term) =  @_;
+    my $def_index;
+
+    # Re-scan the the grub config file to get the current indexes
+    # of each entry.
+    my $gref = parseGrubCfg();
+    if (!defined($gref)) {
+	print "Cannot parse GRUB configuration file. Exiting...\n";
+	exit 1;
+    }
+
+    # Find the entry that matches the new default version
+    my $entries = $gref->{'entries'};
+    my $entry;
+    foreach $entry (@{$entries}) {
+	# Skip entries that are not using the same term type as before
+	next if ($entry->{'term'} ne $def_term);
+	# Skip the password reset entries
+	next if ($entry->{'reset'});
+	if ($entry->{'ver'} eq $new_def_ver) {
+	    $def_index = $entry->{'idx'};
+	    last;
+	}
+    }
+
+    if (!defined($def_index)) {
+	print "Can't find entry for $new_def_ver in grub config file.\n";
+	exit 1;
+    }
+
+    # Set default pointer in grub config file to point to the new
+    # default version.
+    system("sed -i 's/^set default=.*\$/set default=$def_index/' $grub_cfg");
+    if ($? >> 8) {
+	print "Failed to set the default boot image. Exiting...\n";
+	exit 1;
+    }
+}
+
+# Returns the version string of the currently running system.
+#
 sub curVer {
-  my ($fd, $ver) = (undef, undef);
-  open($fd, '<', $VER_FILE) or return undef;
-  while (<$fd>) {
-    next if (!(/^Version\s+:\s+(\S+)$/));
-    $ver = $1;
-    last;
-  }
-  close($fd);
-  return $ver;
+    my ($fd, $ver) = (undef, undef);
+
+    my $image_boot = `grep -e '^unionfs / unionfs.*squashfs=ro' /proc/mounts`;
+    if ($image_boot ne "") {
+	open($fd, '<', $VER_FILE) or return undef;
+	while (<$fd>) {
+	    next if (!(/^Version\s+:\s+(\S+)$/));
+	    $ver = $1;
+	    last;
+	}
+	close($fd);
+    } else {
+	$ver = $OLD_IMG_VER_STR;
+    }
+    return $ver;
 }
 
+# Deletes all of the files belonging to the disk-based non-image
+# installation.
+#
 sub del_non_image_files {
     my $logfile="/var/log/vyatta/disk-image-del-";
     $logfile .= `date +%F-%T`;
@@ -290,14 +312,30 @@ sub del_non_image_files {
 }
 
 
+# Takes the boot list entry number selected by the user and deletes
+# the corresponding image.  Deletes all of the grub config file entries
+# associated with that image and deletes the files associated
+# with that entry.
+#
 sub doDelete {
-  my ($bdx) = @_;
-  my $del_ver = ${$bentries}[$resp]->{'ver'};
+  my ($resp, $orig_def_ver, $def_ter, $bentries) = @_;
+  my $del_ver = $ {$bentries}[$resp]->{'ver'};
   my $boot_dir;
 
+  my $cver = curVer();
+  if (!defined($cver)) {
+      print "Cannot verify current version. Exiting...\n";
+      exit 1;
+  }
+  if ($cver eq $del_ver) {
+      print "Cannot delete current running image. Reboot into a different\n";
+      print "image to delete this image.  Exiting...\n";
+      exit 1;
+  }
+
   print "Are you sure you want to delete the\n\"$del_ver\" image? ";
   print '(Yes/No) [No]: ';
-  my $resp = <STDIN>;
+  $resp = <STDIN>;
   if (!defined($resp)) {
     $resp = 'no';
   }
@@ -308,19 +346,6 @@ sub doDelete {
     exit 1;
   }
 
-  my $cver = curVer();
-  if (!defined($cver)) {
-    print "Cannot verify current version. Exiting...\n";
-    exit 1;
-  }
-  if ($cver eq $del_ver) {
-    print <<EOF;
-Cannot delete current running image. Reboot into a different version
-before deleting. Exiting...
-EOF
-    exit 1;
-  }
-
   if (-d $UNION_BOOT) {
     $boot_dir = $UNION_BOOT;
   } elsif (-d $DISK_BOOT) {
@@ -350,6 +375,105 @@ EOF
   }
 
   print "Done\n";
+
+  # Need to reset the grub default pointer becuase entry before default
+  # may have been deleted, or the default entry itself may have
+  # been deleted.
+  if ($del_ver eq $orig_def_ver) {
+      select_by_name($cver, $def_ter);
+      print "The default image has been changed to the currently running image:\n";
+      print "$cver\n";
+  } else {
+      select_by_name($orig_def_ver, $def_ter);
+  }
+
   exit 0;
 }
 
+#
+# Main section
+# 
+
+my ($show, $del, $sel) = (undef, undef, undef);
+
+GetOptions(
+  'show' => \$show,
+  'delete' => \$del,
+  'select' => \$sel
+);
+
+if (-e $UNION_GRUB_CFG) {
+    $grub_cfg = $UNION_GRUB_CFG;
+} elsif (-e $OLD_GRUB_CFG) {
+    $grub_cfg = $OLD_GRUB_CFG;
+} else {
+    print "Can not open Grub config file\n";
+    exit 1;
+}
+
+my $gref = parseGrubCfg();
+if (!defined($gref)) {
+    print "Cannot find GRUB configuration file. Exiting...\n";
+    exit 1;
+}
+
+my $def_idx = $gref->{'default'};
+my $entries = $gref->{'entries'};
+if (!defined($def_idx) || !defined($entries)
+    || !defined(${$entries}[$def_idx])) {
+  print "Error parsing GRUB configuration file. Exiting...\n";
+  exit 1;
+}
+my $def_ver = ${$entries}[$def_idx]->{'ver'};
+my $def_term = ${$entries}[$def_idx]->{'term'};
+
+my $bentries = getBootList($def_term, $entries);
+if ($#{$bentries} < 0) {
+  print "No images found. Exiting...\n";
+  exit 1;
+}
+
+my $msg = 'The system currently has the following image(s) installed:';
+if (defined($del)) {
+  # doing delete
+  $msg = 'The following image(s) can be deleted:';
+}
+print "$msg\n\n";
+displayBootList($def_idx, $bentries);
+print "\n";
+
+exit 0 if (defined($show) || (!defined($sel) && !defined($del))); # show-only
+
+# for doing select
+my $prompt_msg = 'Select the default boot image: ';
+my $error_msg = 'Invalid selection. Default is not changed.';
+if ($del) {
+  # doing delete
+  $prompt_msg = 'Select the image to delete: ';
+  $error_msg = 'Invalid selection. Nothing is deleted.';
+}
+
+print "$prompt_msg";
+my $resp = <STDIN>;
+if (defined($resp)) {
+  chomp($resp);
+  if (!($resp =~ /^\d+$/) || ($resp < 1) || ($resp > ($#{$bentries} + 1))) {
+    $resp = undef;
+  }
+}
+if (!defined($resp)) {
+  print "$error_msg Exiting...\n";
+  exit 1;
+}
+print "\n";
+
+$resp -= 1;
+
+if ($sel) {
+  doSelect($resp, $def_ver, $bentries);
+} elsif ($del) {
+  doDelete($resp, $def_ver, $def_term, $bentries);
+}
+
+exit 0;
+