Ubuntu-Debian APT upgrade script

system_update.sh

#!/bin/bash
#
# Brady Shea - 18SEP2020 - conversion of system_update alias to bash script
# https://www.holylinux.net/
#
# Place this script in "/usr/local/sbin/system_update" or similar location under your $PATH
# It needs root permissions (SUDO) to execute.
#
# Change these settings to your liking:
#################################
noprompting=true                # ( true | false ) (APT option:  -y, --yes, --assume-yes)
sleepy=5                        # Pause a bit between autoremoves and updates
bootpartitionwarning=102400     # 102400 1kb blocks (~100MiB) is a reasonable amount
#################################

# STATIC VARIABLES #
BRIGHT_RED=$(tput bold)$(tput setaf 1)
BRIGHT_GREEN=$(tput bold)$(tput setaf 2)
GREEN=$(tput setaf 2)
BRIGHT_YELLOW=$(tput bold)$(tput setaf 3)
BRIGHT_WHITE=$(tput bold)$(tput setaf 7)
COLOR_OFF=$(tput sgr0)
scriptname=`basename "$0"`
rebootfileflag=/var/run/reboot-required

# OTHER VARIABLES #
noprompt=
if [[ $noprompting == "true" ]]; then
  noprompt=-y
fi
rebootreq=0
bootavail=0
problems=0

# FUNCTIONS #
root_user () { [ ${EUID:-$(id -u)} -eq 0 ]; }
## No point going any further in script if not sudo:
if ! root_user; then printf "\nPlease use: \'sudo ${scriptname}\'\nExiting.\n\n"; exit; fi

sleeptimer () {
  for (( count=1; count<=$sleepy; count++ )); do
    printf "${BRIGHT_WHITE}.${COLOR_OFF}"; sleep 1;
  done
  printf "\n"
}

rebootcheck () {
  rebootreq="false"
  if [ -f $rebootfileflag ]; then
    rebootreq="true"
  fi
}

okaynookay () {
  showalert="${GREEN}(PASS)${COLOR_OFF}"
  if [ $problems == "1" ]; then
    showalert="${BRIGHT_RED}(FAIL)${COLOR_OFF}"
  fi
  problems=0
}

# MAIN PROGRAM #
printf "\n${BRIGHT_YELLOW}SYSTEM UPDATE STARTED${COLOR_OFF}\n\n"

printf " ${BRIGHT_WHITE}Current Distribution:${COLOR_OFF} %b %b %b\n" $(lsb_release -sd)

bootavail=$(df --output=avail /boot | tail -n 1)
if [[ $bootavail -lt bootpartitionwarning ]]; then
  problems=1; okaynookay
  displaybootavail="${bootavail} ${showalert}"
else
  problems=0; okaynookay
  displaybootavail="${bootavail} ${showalert}"
fi
printf " ${BRIGHT_WHITE}Available /boot space:${COLOR_OFF} %s %s\n" $displaybootavail

rebootcheck ## (pre update)
if [[ $rebootreq == "true" ]]; then
  problems=1; okaynookay;
  displayrebootreq="${rebootreq} ${showalert}"
else
  problems=0; okaynookay;
  displayrebootreq="${rebootreq} ${showalert}"
fi
printf " ${BRIGHT_WHITE}Reboot required currently:${COLOR_OFF} %s %s\n" $displayrebootreq

if [[ $rebootreq == "true" || $bootavail -lt $bootpartitionwarning ]]; then
  while true; do
    read -p " $(echo -e "You have warnings. Proceed anyway? [y/N] ")" userinput
    case $userinput in
      [Yy]* ) break;;
      [Nn]* ) exit;;
      * ) exit;;
    esac
  done
fi

# START UPDATE #

printf "\n${BRIGHT_WHITE}Updating from sources..${COLOR_OFF}\n"
apt update

printf "\n${BRIGHT_WHITE}Running autoremove before updates..${COLOR_OFF}\n"
apt ${noprompt} autoremove

printf "\n${BRIGHT_WHITE}Autoremove completed. Sleeping ${sleepy} seconds${COLOR_OFF}"; sleeptimer

printf "\n${BRIGHT_WHITE}Installing any upgrades found..${COLOR_OFF}\n"
apt ${noprompt} upgrade

printf "\n${BRIGHT_WHITE}Updates have completed. Sleeping ${sleepy} seconds${COLOR_OFF}"; sleeptimer

printf "\n${BRIGHT_WHITE}Re-running autoremove post-updates..${COLOR_OFF}\n"
apt ${noprompt} autoremove

rebootcheck ## (post update)
if [[ $rebootreq == "true" ]]; then
    printf "\n${BRIGHT_RED} *** A system reboot is required. ***${COLOR_OFF}\n"
else
    printf "\n${GREEN} A system reboot is NOT required at this time.${COLOR_OFF}\n"
fi
printf "\n${BRIGHT_YELLOW}SYSTEM UPDATE COMPLETED. Exiting.${COLOR_OFF}\n\n"

A 'clean' way to do apt updates on debian/ubuntu/etc.. with autoremove.
I have used something similar to this for years and have never had a problem with updates/upgrades.

Using Script

• It needs root permissions (SUDO) to execute.
• Place this script in /usr/local/sbin/system_update (or similar location under your $PATH)

Permissions:
$ sudo chmod 755 /usr/local/sbin/system_update

Execute:
$ sudo system_update

I have added a sudo check, a reboot check (pre and post update) and a /boot space check as well (Updated 19JUN2021):

Failure(s) will look like this:

A failure is either low /boot space, or a reboot is needed (less than 100MiB default - see bootpartitionwarning in adjustable variables).
These should probably be corrected before proceeding. You can of course continue the update, but you were warned.

Nice script. Thanks for posting and I appreciated the documentation. This was exactly the type of inspiration I needed for the script I'm working on.

@jcanfield

No prob and thanks. Think you are first person who noticed it. haha
Yeah - got tired of friends/other admins saying Debian/Ubuntu/others sucks because APT UPGRADE screwed up a system.

Seems to usually happen because they run out of space in /boot halfway through an upgrade and were not warned beforehand. (/boot being a separate mount point).

Not sure why default aptitude/apt scripts doesn't at least do a 'free space check' and warning on /boot (or whole disk) before applying more kernel updates to same area. This has been an "issue" with upgrading Debian/et al since the beginning.

And for same reasons, why is 'apt autoremove' not run automatically before an upgrade to clean up kernels before 'apt upgrade' runs.

The reboot warning isn't as big a deal, but is still checked (why not?).
Though you can (usually) run an upgrade successfully when the reboot flag is true.

-Brady