Auto-Notification

This repository contains two Bash scripts designed for monitoring user logins and system disk usage. Notifications are sent via Telegram Bot. Below is a detailed explanation of each script, their functionality, and how to set them up.

Scripts Overview

1. PAM Hook Script

Purpose: Monitors user sessions (login and logout) and sends notifications via Telegram whenever a user connects or disconnects from the system.
Trigger: The script is invoked by PAM (Pluggable Authentication Module) during session events (e.g., SSH login).
Notification Content:
- Username ($PAM_USER)
- Remote host ($PAM_RHOST)
- Timestamp ($(date))

2. Disk Monitoring Script

Purpose: Monitors disk usage on the root filesystem (/) and sends an alert if the usage exceeds a predefined threshold.
Trigger: Can be run manually, or scheduled to run periodically using Cron.
Notification Content:
- Current disk usage percentage.
- Total disk size, used space, and available space.

Prerequisites

Linux Environment:
- Both scripts are designed to work on Linux systems.
- Ensure PAM is available for the login monitoring script.
Telegram Bot Setup:
- Create a Telegram bot by talking to BotFather.
- Save the bot token (TOKEN).
- Get your CHAT_ID by sending a message to the bot and using an API call like:
```
curl https://api.telegram.org/bot<YOUR_TOKEN>/getUpdates
```
- Add these variables (TOKEN and CHAT_ID) to the .env file.
Environment File (.env):
- Place the .env file in /etc/serverconfig/.env.
- Example .env file:
```
TOKEN=your_bot_token_here
CHAT_ID=your_chat_id_here
```
Dependencies:
- Ensure curl is installed:
```
sudo apt install curl
```

Installation & Configuration

1. PAM Hook Script

Place the Script:
- Save the script as /usr/local/bin/sshd-login.sh.
- Make it executable:
```
sudo chmod +x /usr/local/bin/sshd-login.sh
```
Configure PAM:
- Edit the PAM configuration for the service you want to monitor. For SSH:
```
sudo nano /etc/pam.d/sshd
```
- Add the following line to trigger the script:
```
session optional pam_exec.so /usr/local/bin/sshd-login.sh
```
Test the Setup:
- Log in and out of the system via SSH.
- Check Telegram for notifications.

2. Disk Monitoring Script

Place the Script:
- Save the script as /usr/local/bin/disk-monitor.sh.
- Make it executable:
```
sudo chmod +x /usr/local/bin/disk-monitor.sh
```
Run Manually:
- Execute the script with a threshold percentage:
```
/usr/local/bin/disk-monitor.sh
```
Automate with Cron:
- Schedule the script to run periodically:
```
crontab -e
```
- Add a cron job, e.g., to check disk usage every hour:
```
0 * * * * /usr/local/bin/disk-monitor.sh
```

Security Considerations

Restrict Access to Scripts and .env:

Ensure only root or authorized users can access these files:

sudo chmod 600 /etc/serverconfig/.env
sudo chmod 700 /usr/local/bin/sshd-login.sh
sudo chmod 700 /usr/local/bin/disk-monitor.sh

Conclusion

These scripts provide a lightweight solution for real-time session monitoring and disk usage alerts via Telegram. By integrating with PAM and automating periodic checks, they enhance system monitoring and improve administrator response time to critical events.