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 eval $(apt-config shell APT_CONF_D Dir::Etc::parts/d)
  26 test -n "${APT_CONF_D}" || APT_CONF_D="/etc/apt/apt.conf.d"
  27 config_file=${APT_CONF_D}/01autoremove-kernels
  28
  29 eval $(apt-config shell DPKG Dir::bin::dpkg/f)
  30 test -n "$DPKG" || DPKG="/usr/bin/dpkg"
  31
  32 installed_version="$1"
  33 running_version="$(uname -r)"
  34
  35
  36 version_test_gt ()
  37 {
  38         local version_test_gt_sedexp="s/[._-]\(pre\|rc\|test\|git\|old\|trunk\)/~\1/g"
  39         local version_a="`echo "$1" | sed -e "$version_test_gt_sedexp"`"
  40         local version_b="`echo "$2" | sed -e "$version_test_gt_sedexp"`"
  41         $DPKG --compare-versions "$version_a" gt "$version_b"
  42         return "$?"
  43 }
  44
  45 list=$(${DPKG} -l 'linux-image-[0-9]*'|awk '/^ii/ && $2 !~ /-dbg$/ { print $2 }' | sed -e's/linux-image-//')
  46
  47 latest_version=""
  48 previous_version=""
  49 for i in $list; do
  50         if version_test_gt "$i" "$latest_version"; then
  51                 previous_version="$latest_version"
  52                 latest_version="$i"
  53         elif version_test_gt "$i" "$previous_version"; then
  54                 previous_version="$i"
  55         fi
  56 done
  57
  58 if [ "$latest_version" != "$installed_version" ] \
  59    || [ "$latest_version" != "$running_version" ] \
  60    || [ "$installed_version" != "$running_version" ]
  61 then
  62         # We have at least two kernels that we have reason to think the
  63         # user wants, so don't save the second-newest version.
  64         previous_version=
  65 fi
  66
  67 kernels=$(sort -u <<EOF
  68 $latest_version
  69 $installed_version
  70 $running_version
  71 $previous_version
  72 EOF
  73 )
  74
  75 generateconfig() {
  76         cat <<EOF
  77 // File autogenerated by $0, do not edit
  78 APT
  79 {
  80   NeverAutoRemove
  81   {
  82 EOF
  83         apt-config dump --no-empty --format '%v%n' 'APT::VersionedKernelPackages' | while read package; do
  84                 for kernel in $kernels; do
  85                         echo "    \"^${package}-${kernel}$\";"
  86                 done
  87         done
  88         cat <<EOF
  89   };
  90 };
  91 EOF
  92 }
  93 generateconfig > "${config_file}.dpkg-new"
  94 mv "${config_file}.dpkg-new" "$config_file"