serverconfig/notification/README.md

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.

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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))

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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.

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Prerequisites

1. Linux Environment:

   • Both scripts are designed to work on Linux systems.
   • Ensure PAM is available for the login monitoring script.

2. 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.

3. 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
     

4. Dependencies:

   • Ensure curl is installed:

     sudo apt install curl
     

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Installation & Configuration

1. PAM Hook Script

1. 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
     

2. 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
     

3. Test the Setup:

   • Log in and out of the system via SSH.
   • Check Telegram for notifications.

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2. Disk Monitoring Script

1. 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
     

2. Run Manually:

   • Execute the script with a threshold percentage:

     /usr/local/bin/disk-monitor.sh
     

3. 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
     

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Security Considerations

1. 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

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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.