send_telegram_notif.sh

#!/bin/bash
# Version 1.0
# Send Fail2ban notifications using a Telegram Bot

# Add to the /etc/fail2ban/jail.conf:
# [sshd]
# ***
# action  = iptables[name=SSH, port=22, protocol=tcp]
#			telegram

# Create a new file in /etc/fail2ban/action.d with the following information:
# [Definition]
# actionstart = /etc/fail2ban/scripts/send_telegram_notif.sh -a start 
# actionstop = /etc/fail2ban/scripts/send_telegram_notif.sh -a stop
# actioncheck = 
# actionban = /etc/fail2ban/scripts/send_telegram_notif.sh -n <name> -b <ip>
# actionunban = /etc/fail2ban/scripts/send_telegram_notif.sh -n <name> -u <ip>
# 
# [Init]
# init = 123

# Telegram BOT Token 
telegramBotToken='YOUR_BOT_TOKEN'

# Telegram Chat ID
telegramChatID='YOUR_CHAT_ID'

function talkToBot() {
	message=$1
	curl -s -X POST https://api.telegram.org/bot${telegramBotToken}/sendMessage -d text="${message}" -d chat_id=${telegramChatID} > /dev/null 2>&1
}

if [ $# -eq 0 ]; then
	echo "Usage $0 -a ( start || stop ) || -b \$IP || -u \$IP"
	exit 1;
fi

while getopts "a:n:b:u:" opt; do
	case "$opt" in
		a)
			action=$OPTARG
		;;
		n)
			jail_name=$OPTARG
		;;
		b)
			ban=y
			ip_add_ban=$OPTARG
		;;
		u)
			unban=y
			ip_add_unban=$OPTARG
		;;
		\?) 
			echo "Invalid option. -$OPTARG" 
			exit 1
		;;
	esac
done

if [[ ! -z ${action} ]]; then
	case "${action}" in
		start)
			talkToBot "Fail2ban has been started"
		;;
		stop)
			talkToBot "Fail2ban has been stopped"
		;;
		*)
			echo "Incorrect option"
			exit 1;
		;;
	esac
elif [[ ${ban} == "y" ]]; then
	talkToBot "[${jail_name}] The IP: ${ip_add_ban} has been banned"
	exit 0;
elif [[ ${unban} == "y" ]]; then
	talkToBot "[${jail_name}] The IP: ${ip_add_unban} has been unbanned"
	exit 0;
else
	info
fi