bashscripts/updates_notifier.sh

#!/bin/bash

# uncomment when use script from cron
PATH=$PATH:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin

#verify run as root or sudo
if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root"
   exit 1
fi

# vars gotify
readonly GOTIFY_TOKEN="<TOKEN_GOTIFY_APP>"
readonly GOTIFY_HOST="<GOTIFY_HOST>"
readonly GOTIFY_PRIORITY=5

apt update -qq

#https://askubuntu.com/questions/269606/apt-get-count-the-number-of-updates-available
num=`apt-get -q -y --ignore-hold --allow-change-held-packages --allow-unauthenticated -s dist-upgrade | /bin/grep  ^Inst | wc -l`;

if [ "$num" -eq "0" ]; then
	echo "No updates";
	exit;
else
	#echo "There are $num updates";
	updates=`apt-get --fix-missing --no-download -s dist-upgrade -V | grep '=>' | awk '{print$1}';`
	updates=$(echo $updates|tr -d '\n')
	OUT="There are **$num** updates:  \r"
	OUT="${OUT} Packages: *$updates*"

  # send gotify notification
  TITLE="$(hostname) pending updates"
  EXTRAS="{\"client::display\": {\"contentType\": \"text/markdown\"}}"
  curl -X POST "$GOTIFY_HOST/message?token=$GOTIFY_TOKEN" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"message\": \"${OUT}\", \"priority\": ${GOTIFY_PRIORITY}, \"title\": \"${TITLE}\", \"extras\": ${EXTRAS} }"
fi