Check nextcloud for aliveness using tcp ping with lft, send notification to telegram if it's dead. See https://gist.github.com/jogerj/47eca63335c93b214c9bc72347139756

check_nextcloud.sh

#!/bin/bash

source /root/telegram.sh

fixes_dir="/root"
check_website="nextcloud.acme.com"

ip_address="$(dig +short @1.1.1.1 $check_website)"

if [ "x$ip_address" == "x" ]; then
    echo "[ERROR] $(date -R) - ${title} DNS record not found!" >> $fixes_dir/cloud_alive.log
    if [ ! -f $fixes_dir/.cloudlivechecked ]; then
        touch $fixes_dir/.cloudlivechecked;
        echo "[WARN] $(date -R) - Sent DNS error notification for ${check_website}" >> $fixes_dir/cloud_alive.log
        send_telegram "$check_website" "$(echo -e "Failed to resolve ${check_website}!")";
    fi;
    exit 1;
fi;

check="$(/usr/sbin/lft -S -z -d 443 ${check_website})"
check_alive="$(echo -e $check | grep -oP "$ip_address:443\s.+ms")"

if [ "x$check_alive" == "x" ]; then
    echo "[ERROR] $(date -R) - ${check}" >> $fixes_dir/cloud_alive.log
    if [ ! -f $fixes_dir/.cloudlivechecked ]; then
        touch $fixes_dir/.cloudlivechecked;
        echo "[WARN] $(date -R) - Sent error notification for ${check_website}" >> $fixes_dir/cloud_alive.log;
        send_telegram "$check_website" "$(echo -e "${check}\n\nNextcloud failed to respond!")";
    fi;
else
    # all is good
    if [ -f $fixes_dir/.cloudlivechecked ]; then
        echo "[INFO] $(date -R) - Sent online notification for ${check_website}" >> $fixes_dir/cloud_alive.log
        send_telegram "$check_website" "$(echo -e "${check}\n\nNextcloud is back online!")";
        rm -f $fixes_dir/.cloudlivechecked
    fi;
fi;