linux-kernel-autoremove

#!/bin/bash
# linux-kernel-autoremove (part of ossobv/vcutil) // wdoekes/2016-2019
#   // Public Domain
#
# Automatically remove old unused kernels on Debian and Ubuntu platforms.
#
# On hosts with auto updating on, a large collection of old kernels can
# pile up and collect dust.  This utility greps for all linux-image-*,
# linux-modules-* and linux-headers-* and keeps only two, apt-get
# removing the rest.  It prefers to keep the latest and running kernels.
#
# Usage:
#
#     linux-kernel-autoremove       # lists what it would remove
#     linux-kernel-autoremove -f    # apt-get removes those packages
#
# Bugs: right now, it doesn't correlate headers or modules to images. So
# if you've stopped updating headers/modules, this utility won't clean
# up old versions for you.
#
set -ue

list_packages_other_than_current_and_latest_kernel() {
    # Take <prefix> (linux-image) and add current uname version, but
    # remove trailing stuff like "-generic".
    prefix="$1"  # e.g. "linux-image", "linux-headers"
    current="$prefix-$(uname --kernel-release | sed -e 's/\(.*[0-9]\).*/\1/')"
    latest=$(dpkg -l "$prefix-[0-9]*" 2>/dev/null | awk '/^ii/{print $2}' |
             sort -V | sed -e 's/\(.*[0-9]\).*/\1/' | tail -n1)
    alldpkg=$(dpkg -l "$prefix-[0-9]*" 2>/dev/null |
              awk '/^[ir][ic]  /{print $2}' | sort -V)
    currentdpkg=$(dpkg -l "$current*" 2>/dev/null | awk '/^ii/{print $2}')

    if test -z "$latest"; then
        if test "$prefix" = "linux-headers" ||
                test "$prefix" = "linux-modules"; then
            # echo "(ignoring $prefix; doesn't exist)" >&2
            return
        else
            echo "ERROR: $current not installed. Please fix manually." >&2
            exit 1
        fi
    fi

    if test -z "$currentdpkg"; then
        echo "WARNING: $current not installed. Please double check." >&2
        echo >&2
    fi

    # Is already latest? Then use the previous one as current, so we
    # keep two.
    if test "$latest" = "$current"; then
        current=$(dpkg -l "$prefix-[0-9]*" 2>/dev/null |
                  awk '/^ii/{print $2}' | sed -e 's/\(.*[0-9]\).*/\1/' |
                  sort -uV | tail -n2 | head -n1)
    fi

    for pkg in $alldpkg; do
        # bash-isms in the if-globbing here, so we can find both
        # linux-headers-4.15.0-50 and linux-headers-4.15.0-50-generic.
        if ! test "$pkg" = "$currentdpkg" &&
                ! [[ "$pkg" = "$current"* ]] &&
                ! [[ "$pkg" = "$latest"* ]]; then
            echo $pkg
        fi
    done
}

# Run by importance first. If there is no image, we'll want to abort fast.
# Headers are not mandatory, nor are modules.
packages=$(
    list_packages_other_than_current_and_latest_kernel linux-image
    list_packages_other_than_current_and_latest_kernel linux-modules
    list_packages_other_than_current_and_latest_kernel linux-headers
)
force="${1:-}"
if test "$force" = "-f"; then
    test -n "$packages" && apt-get -y remove --purge $packages
    true
elif test -n "$packages"; then
    echo "Supply -f to remove these packages:"
    echo "$packages" | sed -e 's/^/  /'
else
    echo "Nothing to remove." >&2
    false
fi

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