#!/bin/bash
# Remove old kernels safely and cleanly. As it uses urpme, grub is automatically updated.
#
# LISTK contains the list of kernels to analyse
# The script keep the NBK most recents for each of them
# Pierre Jarillon - 3 avril 2018 - Tested on Mageia 5..8
# Jean-Baptiste Biernacki 2021
# rev 2021-08-07 PJ

# Script permettant de supprimer les anciens kernels
# Si il est lancé en tant que root, il propose de supprimer les kernels écrits en rouge. Si on le lance sans être root, il fait le test de la même façon mais affiche "Must be root" et se termine.

# Nouvelle version ajoutant la protection du noyau en cours et des options.

# Utilisation : remove-old-kernels : [-a] [-d] [-n valeur]
# -a = automatique, pas de question. Interactif si non spécifié
# -d = mode débogage ou test, rien n'est supprimé, urpme est simulé
# -n valeur = nombre de noyaux à garder (-n3 ou -n 3 garde 3 noyaux), Min=2, Défaut=2

# Par exemple remove-old-kernels -d -a ( ou -ad ou -ad) permet de simuler un mode automatique sans rien modifier.

# Ce script peut être lancé avec plusieurs options. Pour les afficher :
# remove-old-kernels -?

# Seul root peut réduire le nombre de kernels. Lancé avec un autre compte, on
# obtient un état des noyaux présents et des packages rpm correspondants.
# Avec le mode -t (ou -d) les modifications sont simulées.

VERSION="Remove-old-kernels 0.9 \n"
DEBUG=0 # 1 for debug/test mode, urpme is simulated and not applied
NBK=2 # Number of kernels to keep
MODE="I" # mode A)utomatic, I)nteractve
VISU=0 # If VISU=1, show commands which can be used

USAGE=\
"Usage: %s: [-a] [-d] [-t] [-n value] [-p]
-a = automatic, no question. Interactive if not specified
-d or -t = Debug or test mode, nothing is removed, urpme is simulated
-n value = number of kernels to keep (-n3 or -n 3 keep 3 kernels), Min=2, Default=2
-p = show (print) the urpme commands which can be used
-v = version
-? or -h = show this help.
Old kernels are removed safely and cleanly. As urpme is used, grub is automatically updated.\n
"

# Colors
Normal="\033[0m"
Green="\033[32m"
Red="\033[31m"
GrBg="\033[102;30m" # Green Background
ClearLine="\r\033[2K" # Clear the line

LISTK=\
"kernel-desktop586
kernel-desktop
kernel-desktop-devel
kernel-server
kernel-server-devel
kernel-source
kernel-tmb-desktop
kernel-tmb-desktop-devel
kernel-tmb-source
kernel-linus
kernel-linus-devel
kernel-linus-source
"

#Parsing arguments

if [[ ${#} -gt 0 ]] ; then
while getopts adtpvn:?h NAME ; do
case ${NAME} in
a) MODE="A";;
d|t) DEBUG=1 ;;
p) VISU=1 ;;
n) NBK=${OPTARG} ;;
v) printf "${VERSION}"
exit 2;;
?|h) printf "${USAGE}" ${0}
exit 2;;
esac
done
if [[ ${NBK} -lt 2 ]]; then
NBK=2 # Unsafe if less
fi
fi

# Get the release of the current kernel
CURK=$(uname -r | cut -d- -f1)
# Storage for the list of kernels to remove
TMPKTR=$(mktemp)
# Check storage usage on root partition
OCCDISK1=$(df -B 1k -l --output=used / | tail -n1 | awk '{ print $1 }')

#================================= Analyse /boot/ =============================

NK=$(ls /boot/vmlinuz*.mga* | wc -l)
echo -e "${GrBg} Number of kernels in /boot/ : ${NK} ${Normal} "

#================================= Analyse rpm =============================
for kernelType in ${LISTK} ; do
echo -ne "${ClearLine}"
echo -ne "\r ==> ${kernelType}"
export n=0;
installedKernelCounter=0;

rpm -qa --last "${kernelType}-[0-9]*" | while read installedKernel ; do
# Not possible, as it is kernelType-[0-9]andAnything and kernelType-lastest is not included.
# [ $(echo ${installedKernel} | grep "latest" | wc -l ) -eq 1 ] && continue # Security
installedKernelCounter=$((${installedKernelCounter} + 1))
#Return to the line if there exists at least one installedKernel of this kernelType
if [[ ${installedKernelCounter} -eq 1 ]] ; then echo "" ; fi
installedKernelPackage=$(echo ${installedKernel} | cut -d ' ' -f 1 )

if [[ $(echo ${installedKernel} | grep ${CURK} | wc -l ) -eq 1 ]] ; then
NOTA="used now " # current kernel
REMVBL=0 # not removable
else
NOTA="" # not currently used
REMVBL=1 # is removable
fi

if [[ ${installedKernelCounter} -gt $NBK ]] ; then
if [[ ${REMVBL} -ne 1 ]] ; then
echo -e "\r ${installedKernelCounter} : keep : ${Green}${installedKernel} ${Normal}${NOTA}"
else
echo -e "\r ${installedKernelCounter} : remove : ${Red}${installedKernel} ${Normal}${NOTA}"
echo ${installedKernelPackage} >>${TMPKTR}
fi
else
echo -e "\r ${installedKernelCounter} : keep : ${Green}${installedKernel} ${Normal}${NOTA}"
fi
done
done

echo -e "${ClearLine}"

#================================= Mode of execution ===================

nbt=$(cat ${TMPKTR} | wc -l)
if [[ ${nbt} -ne 0 ]] ; then
if [[ $(id -u) -ne 0 ]] ; then
echo "Must be root to allow urpme"
if [ ${VISU} -eq 1 ]; then
for f in $(tac ${TMPKTR}) ; do
echo "urpme ${f}"
done
fi
else
if [[ ${MODE} != "A" ]] ; then
if [[ ${DEBUG} -eq 1 ]] ; then
echo -e "\n${Green}>> Debug/test mode is on - kernels won't be removed <<${Normal}"
fi
plural="s" ; [ ${nbt} -eq 1 ] && plural=""
read -p "Remove ${nbt} kernel${plural} ? y/N/i (i=confirm for each) " -n 1 response
if [[ -z ${response} ]] ; then response="n" ; fi
case ${response} in
[Yy])
AUTO="--auto"
ASK=0
MODE="A"
echo -e " \n" ;;
[Ii])
AUTO="--auto"
MODE="I"
echo " interactif" ;;
*)
echo -e "\nAborted"
rm -f ${TMPKTR}
exit 0 ;;
esac
fi

#================================= Execution ===========================


for installedKernelPackage in $(tac ${TMPKTR}) ; do
if [[ ${MODE} = "I" ]] ; then # --- interactive mode ---
read -p "Remove ${installedKernelPackage} ? y/N/q (q=quit/abort) " -n 1 response
if [[ -z ${response} ]] ; then response="N" ; fi
case ${response} in
[Yy])
if [[ ${DEBUG} -eq 1 ]] ; then
echo "\nDEBUG: Could execute: urpme ${AUTO} ${installedKernelPackage}"
nbt=$((${nbt} - 1))
else
urpme ${installedKernelPackage}
nbt=$((${nbt} - 1))
fi
;;
[qQ])
echo -e "\nAborted"
rm -f ${TMPKTR}
exit 0 ;;
*)
#echo "do nothing"
continue
;;
esac
else # --- automatic mode ---
if [[ ${DEBUG} -eq 1 ]] ; then
echo "DEBUG: Could execute: urpme ${AUTO} ${installedKernelPackage}"
nbt=$((${nbt} - 1))
else
#echo "Here is the execution"
urpme ${AUTO} ${installedKernelPackage}
nbt=$((${nbt} - 1))
fi
fi
done

NK=$(ls /boot/vmlinuz*.mga? | wc -l)
OCCDISK2=$(df -B 1k -l --output=used / | tail -n1 | awk '{ print $1 }')
echo -e "${GrBg} Gain : $((OCCDISK1 - OCCDISK2)) k - Kernels in /boot/: ${NK} ${Normal}"
fi
fi

rm -f ${TMPKTR}

# Run again if some removable kernels are left
[ $(id -u) -ne 0 ] && exit 0
[ ${MODE} != "I" ] && exit 0
[ ${nbt} -gt 0 ] && ${0}