add op command for image removal

1 files changed, 178 insertions, 20 deletions

diff --git a/scripts/vyatta-boot-image.pl b/scripts/vyatta-boot-image.pl
index 23dd7a0..7a4a85d 100755
--- a/scripts/vyatta-boot-image.pl
+++ b/scripts/vyatta-boot-image.pl
@@ -3,8 +3,12 @@
 use strict;
 use warnings;
 use Getopt::Long;
+use File::Temp qw/ :mktemp /;
 
-my $UNION_GRUB_CFG = '/live/image/boot/grub/grub.cfg';
+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';
 
 # this function parses the grub config file and returns a hash reference
 # of the parsed data.
@@ -34,7 +38,7 @@ sub parseGrubCfg {
           $ehash{'ver'} = $1;
         } else {
           # old install
-          $ehash{'ver'} = 'Old non-image installation';
+          $ehash{'ver'} = $OLD_IMG_VER_STR;
         }
         if (/console=tty0.*console=ttyS0/) {
           $ehash{'term'} = 'serial';
@@ -59,18 +63,75 @@ 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.
+sub deleteGrubEntries {
+  my ($del_ver) = @_;
+
+  my $rfd = undef;
+  return 'Cannot delete GRUB entries' if (!open($rfd, '<', $UNION_GRUB_CFG));
+  my ($wfd, $tfile) = mkstemp('/tmp/boot-image.XXXXXX');
+
+  my @entry = ();
+  my ($in_entry, $ver) = (0, 0);
+  while (<$rfd>) {
+    next if (/^$/); # ignore empty lines
+    if ($in_entry) {
+      if (/^}/) {
+        if ($ver ne $del_ver) {
+          # output entry
+          print $wfd "\n";
+          foreach my $l (@entry) {
+            print $wfd $l;
+          }
+          print $wfd "}\n";
+        }
+        $in_entry = 0;
+        $ver = 0;
+        @entry = ();
+      } else {
+        if (/^\s+linux \/boot\/([^\/ ]+)\/.* boot=live /) {
+          # kernel line
+          $ver = $1;
+        }
+        push @entry, $_;
+      }
+    } elsif (/^menuentry /) {
+      $in_entry = 1;
+      push @entry, $_;
+    } else {
+      print $wfd $_;
+    } 
+  }
+  close($wfd);
+  close($rfd);
+
+  my $p = (stat($UNION_GRUB_CFG))[2];
+  return 'Failed to modify GRUB configuration'
+    if (!defined($p) || !chmod(($p & 07777), $tfile));
+  system("mv $tfile $UNION_GRUB_CFG");
+  return 'Failed to delete GRUB entries' if ($? >> 8);
+  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.
 sub getBootList {
-  my ($dterm, $entries) = @_;
+  my ($dver, $dterm, $entries, $delete) = @_;
   my %vhash = ();
   my @list = ();
   foreach (@{$entries}) {
     my ($ver, $term) = ($_->{'ver'}, $_->{'term'});
+    # don't list non-image entry if deleting
+    next if (defined($delete) && $ver eq $OLD_IMG_VER_STR);
+    # don't list default entry if deleting
+    next if (defined($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
+
     $vhash{$ver} = 1;
     push @list, $_;
   }
@@ -90,9 +151,10 @@ sub displayBootList {
   }
 }
 
-my ($show, $sel) = (undef, undef);
+my ($show, $del, $sel) = (undef, undef, undef);
 GetOptions(
   'show' => \$show,
+  'delete' => \$del,
   'select' => \$sel
 );
 
@@ -108,37 +170,133 @@ if (!defined($def_idx) || !defined($entries)
   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);
+my $bentries = getBootList($def_ver, $def_term, $entries, $del);
+if ($#{$bentries} < 0) {
+  print "No images found. Exiting...\n";
+  exit 1;
+}
 
-print "The system currently has the following images installed:\n\n";
+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 ($show); # show-only. done.
+exit 0 if (defined($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 'Select the default boot image: ';
+print "$prompt_msg";
 my $resp = <STDIN>;
-if (!defined($resp) || !($resp =~ /^\d+$/) || ($resp < 1)
-    || ($resp > ($#{$bentries} + 1))) {
-  print "Invalid selection. Default is not changed. Exiting...\n";
+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;
-my $new_idx = ${$bentries}[$resp]->{'idx'};
-my $new_ver = ${$bentries}[$resp]->{'ver'};
-system("sed -i 's/^set default=.*\$/set default=$new_idx/' $UNION_GRUB_CFG");
-if ($? >> 8) {
-  print "Failed to set the default boot image. Exiting...\n";
-  exit 1;
+
+if ($sel) {
+  doSelect($resp);
+} elsif ($del) {
+  doDelete($resp);
 }
-print <<EOF;
+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/' $UNION_GRUB_CFG");
+  if ($? >> 8) {
+    print "Failed to set the default boot image. Exiting...\n";
+    exit 1;
+  }
+  print <<EOF;
 Default boot image has been set to "$new_ver".
 You need to reboot the system to start the new default image.
 
 EOF
-exit 0;
+  exit 0;
+}
+
+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 $ver;
+}
+
+sub doDelete {
+  my ($bdx) = @_;
+  my $del_ver = ${$bentries}[$resp]->{'ver'};
+  print "Are you sure you want to delete the\n\"$del_ver\" image? ";
+  print '(Yes/No) [No]: ';
+  my $resp = <STDIN>;
+  if (!defined($resp)) {
+    $resp = 'no';
+  }
+  chomp($resp);
+  $resp = lc($resp);
+  if ($resp ne 'yes') {
+    print "Image is NOT deleted. Exiting...\n";
+    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/$del_ver") {
+    print "Cannot find the target image. Exiting...\n";
+    exit 1;
+  }
+
+  print "Deleting the \"$del_ver\" image...";
+  my $err = deleteGrubEntries($del_ver);
+  if (defined($err)) {
+    print "$err. Exiting...\n";
+    exit 1;
+  }
+  system("rm -rf '$UNION_BOOT/$del_ver'");
+  if ($? >> 8) {
+    print "Error deleting the image. Exiting...\n";
+    exit 1;
+  }
+
+  print "Done\n";
+  exit 0;
+}