Report downtime with a Telegram bot

A simple bash script that uses a Telegram bot to report if one or more websites are down. Inspired by sitecheck by rla.

Prerequisites

• wget
• curl
• git

Installation

Add a new user that will run the script and switch to the new user

adduser sitecheck
su sitecheck

Fetch the script and create the required files

git clone https://github.com/rsolvang/report-downtime-telegram.git
touch sitelist.txt output.log

Make the script executable and make an environtment file

chmod +x checksite.sh
cp env-example .env

Fill in the correct information in the .env file. Follow the instructions below to create a Telegram bot if you do not already have one.

How to make a Telegram bot

Note: The following steps assumes you already have a Telegram account.

1. Search for @BotFather in your preferred Telegram client.
2. Create a new bot by typing /newbot and give it a common name (Your Bot Name) and a username (yourbotname_bot). Note that the username has to end with "bot" to be valid!
3. Copy your token to a safe place, prefferably a password manager. This token is your authentication to send requests to the Telegram API.

Retrive your Chat ID

You need to tell your bot which user to send messages to. To find your own Chat ID, you need to start a conversation with your newly created bot and send a request through the API:

1. Find your bot in Telegram by searching for it (e.g. @yourbotname_bot)
2. Send your bot a simple message, the content does not matter.
3. Ask your bot for the information on the current conversation by sending the following API request:

• In a browser: https://api.telegram.org/bot<INSERT YOUR TOKEN HERE>/getUpdates
• On a terminal: curl https://api.telegram.org/bot<INSERT YOUR TOKEN HERE>/getUpdates | grep -oP '(?<="from":{"id":)\w+'

Test your connection with the bot

You can verify that your connection with the Telegram bot works by running ./telegram-msg.sh. If you want to send a custom message, add -m "A custom message" as an argument to the script.

Run the script regularly with cron

Add crontab entry to run monitoring every 5 minutes:

*/5 * * * * <PATH-TO>/checksite.sh