debian/apt.auto-removal.sh

   1 #!/bin/sh
   2
   3 set -e
   4
   5 # Author: Steve Langasek <steve.langasek@canonical.com>
   6 #
   7 # Mark as not-for-autoremoval those kernel packages that are:
   8 #  - the currently booted version
   9 #  - the kernel version we've been called for
  10 #  - the latest kernel version (determined using rules copied from the grub
  11 #    package for deciding which kernel to boot)
  12 #  - the second-latest kernel version, if the booted kernel version is
  13 #    already the latest and this script is called for that same version,
  14 #    to ensure a fallback remains available in the event the newly-installed
  15 #    kernel at this ABI fails to boot
  16 # In the common case, this results in exactly two kernels saved, but it can
  17 # result in three kernels being saved.  It's better to err on the side of
  18 # saving too many kernels than saving too few.
  19 #
  20 # We generate this list and save it to /etc/apt/apt.conf.d instead of marking
  21 # packages in the database because this runs from a postinst script, and apt
  22 # will overwrite the db when it exits.
  23
  24
  25 #
  26 eval $(apt-config shell APT_CONF_D Dir::Etc::parts/d)
  27 test -n "${APT_CONF_D}" || APT_CONF_D="/etc/apt/apt.conf.d"
  28 config_file=${APT_CONF_D}/01autoremove-kernels
  29
  30 eval $(apt-config shell DPKG Dir::bin::dpkg/f)
  31 test -n "$DPKG" || DPKG="/usr/bin/dpkg"
  32
  33 installed_version="$1"
  34 running_version="$(uname -r)"
  35
  36
  37 version_test_gt ()
  38 {
  39         local version_test_gt_sedexp="s/[._-]\(pre\|rc\|test\|git\|old\|trunk\)/~\1/g"
  40         local version_a="`echo "$1" | sed -e "$version_test_gt_sedexp"`"
  41         local version_b="`echo "$2" | sed -e "$version_test_gt_sedexp"`"
  42         $DPKG --compare-versions "$version_a" gt "$version_b"
  43         return "$?"
  44 }
  45
  46 list=$($DPKG -l 'linux-image-[0-9]*'|awk '/^ii/ { print $2 }' | sed -e's/linux-image-//')
  47
  48 latest_version=""
  49 previous_version=""
  50 for i in $list; do
  51         if version_test_gt "$i" "$latest_version"; then
  52                 previous_version="$latest_version"
  53                 latest_version="$i"
  54         elif version_test_gt "$i" "$previous_version"; then
  55                 previous_version="$i"
  56         fi
  57 done
  58
  59 if [ "$latest_version" != "$installed_version" ] \
  60    || [ "$latest_version" != "$running_version" ] \
  61    || [ "$installed_version" != "$running_version" ]
  62 then
  63         # We have at least two kernels that we have reason to think the
  64         # user wants, so don't save the second-newest version.
  65         previous_version=
  66 fi
  67
  68 kernels=$(sort -u <<EOF
  69 $latest_version
  70 $installed_version
  71 $running_version
  72 $previous_version
  73 EOF
  74 )
  75
  76 cat > "$config_file".dpkg-new <<EOF
  77 # File autogenerated by $0, do not edit
  78 APT
  79 {
  80   NeverAutoRemove
  81   {
  82 EOF
  83 for kernel in $kernels; do
  84         echo "    \"^linux-image-$kernel.*\";" >> "$config_file".dpkg-new
  85         echo "    \"^linux-image-extra-$kernel.*\";" >> "$config_file".dpkg-new
  86         echo "    \"^linux-signed-image-$kernel.*\";" >> "$config_file".dpkg-new
  87 done
  88 cat >> "$config_file".dpkg-new <<EOF
  89   };
  90 };
  91 EOF
  92 mv "$config_file".dpkg-new "$config_file"