debian/apt.auto-removal.sh

   1 #!/bin/sh
   2 set -e
   3
   4 # Author: Steve Langasek <steve.langasek@canonical.com>
   5 #
   6 # Mark as not-for-autoremoval those kernel packages that are:
   7 #  - the currently booted version
   8 #  - the kernel version we've been called for
   9 #  - the latest kernel version (determined using rules copied from the grub
  10 #    package for deciding which kernel to boot)
  11 #  - the second-latest kernel version, if the booted kernel version is
  12 #    already the latest and this script is called for that same version,
  13 #    to ensure a fallback remains available in the event the newly-installed
  14 #    kernel at this ABI fails to boot
  15 # In the common case, this results in exactly two kernels saved, but it can
  16 # result in three kernels being saved.  It's better to err on the side of
  17 # saving too many kernels than saving too few.
  18 #
  19 # We generate this list and save it to /etc/apt/apt.conf.d instead of marking
  20 # packages in the database because this runs from a postinst script, and apt
  21 # will overwrite the db when it exits.
  22
  23
  24 eval $(apt-config shell APT_CONF_D Dir::Etc::parts/d)
  25 test -n "${APT_CONF_D}" || APT_CONF_D="/etc/apt/apt.conf.d"
  26 config_file=${APT_CONF_D}/01autoremove-kernels
  27
  28 eval $(apt-config shell DPKG Dir::bin::dpkg/f)
  29 test -n "$DPKG" || DPKG="/usr/bin/dpkg"
  30
  31 installed_version="$1"
  32 running_version="$(uname -r)"
  33
  34
  35 version_test_gt ()
  36 {
  37         local version_test_gt_sedexp="s/[._-]\(pre\|rc\|test\|git\|old\|trunk\)/~\1/g"
  38         local version_a="`echo "$1" | sed -e "$version_test_gt_sedexp"`"
  39         local version_b="`echo "$2" | sed -e "$version_test_gt_sedexp"`"
  40         $DPKG --compare-versions "$version_a" gt "$version_b"
  41         return "$?"
  42 }
  43
  44 list="$(${DPKG} -l | awk '/^ii[ ]+(linux|kfreebsd|gnumach)-image-[0-9]/ && $2 !~ /-dbg$/ { print $2 }' | sed -e 's#\(linux\|kfreebsd\|gnumach\)-image-##')"
  45
  46 latest_version=""
  47 previous_version=""
  48 for i in $list; do
  49         if version_test_gt "$i" "$latest_version"; then
  50                 previous_version="$latest_version"
  51                 latest_version="$i"
  52         elif version_test_gt "$i" "$previous_version"; then
  53                 previous_version="$i"
  54         fi
  55 done
  56
  57 if [ "$latest_version" != "$installed_version" ] \
  58    || [ "$latest_version" != "$running_version" ] \
  59    || [ "$installed_version" != "$running_version" ]
  60 then
  61         # We have at least two kernels that we have reason to think the
  62         # user wants, so don't save the second-newest version.
  63         previous_version=
  64 fi
  65
  66 kernels="$(echo "$latest_version
  67 $installed_version
  68 $running_version
  69 $previous_version" | sort -u | sed -e 's#\.#\\.#g' )"
  70
  71 generateconfig() {
  72         cat <<EOF
  73 // DO NOT EDIT! File autogenerated by $0
  74 APT::NeverAutoRemove
  75 {
  76 EOF
  77         apt-config dump --no-empty --format '%v%n' 'APT::VersionedKernelPackages' | while read package; do
  78                 for kernel in $kernels; do
  79                         echo "   \"^${package}-${kernel}$\";"
  80                 done
  81         done
  82         echo '};'
  83 }
  84 generateconfig > "${config_file}.dpkg-new"
  85 mv "${config_file}.dpkg-new" "$config_file"