Born2beroot - 42 Network

Overview

Born2beroot is a system administration project that introduces the fundamentals of virtualization, server security, and Linux configuration. The goal is to set up a secure Debian-based virtual machine while implementing essential security measures and user management.

Project Scope

In this project, you will:

• Install and configure a Debian-based virtual machine (using VirtualBox or UTM).
• Set up a custom user and groups with specific permissions.
• Implement UFW (Uncomplicated Firewall) for security.
• Enforce strong password policies and sudo rules.
• Configure SSH to allow remote connections securely.
• Implement disk partitioning and LVM (Logical Volume Manager).
• Set up and use monitoring tools to track system performance.

Learning Outcomes

• Understanding virtualization and system setup.
• Strengthening knowledge of Linux security best practices.
• Managing users, permissions, and groups effectively.
• Implementing and maintaining firewall configurations.
• Learning LVM partitioning for flexible disk management.
• Using monitoring tools to track system health.

Setup Instructions

1. Install Debian and Configure Virtual Machine

• Use VirtualBox (or UTM for macOS).
• Install a minimal Debian environment without a GUI.

2. User and Group Management

• Create a new user with sudo privileges.
• Configure password expiration policies to enforce security.

3. Security Enhancements

• Install and configure UFW (Uncomplicated Firewall).
• Disable root login via SSH and change the default SSH port.
• Implement strong password policies using pam_pwquality.

4. LVM Partitioning

• Use LVM (Logical Volume Manager) for flexible storage allocation.
• Set up separate partitions for root, home, and swap.

System Monitoring Script

As part of the project, a system monitoring script is required to display important system metrics. Below is the script that automatically runs every 10 minutes, sending a message to all logged-in users via wall.

Script:

#!/bin/bash

# System Architecture
architectur=$(uname -a)

# CPU Information
cpuphysical=$(grep "physical id" /proc/cpuinfo | sort -u | wc -l)
cpuvirtual=$(grep -c "processor" /proc/cpuinfo)

# Memory Usage
memoryusage=$(free --mega | awk '/Mem/ {printf("%d/%dMB (%.2f%%)\n", $3, $2, ($3 / $2) * 100 )}')

# Disk Usage
fulldisk=$(df -BG | awk '/^\/dev/ && !/boot/ {sum += $2} END {print sum}')
usagedisk=$(df -BM | awk '/^\/dev/ && !/boot/ {sum += $3} END {print sum}')
pordisk=$(df -BM | awk '/^\/dev/ && !/boot/ {used+=$3} {total+=$2} END {printf("%.2f"), (used/total)*100}')

# CPU Load
cpuload=$(mpstat 1 1 | awk '/Average/ {printf "%.2f\n", 100 - $NF}')

# Last Boot Time
lastboot=$(uptime -s | cut -c-16)

# LVM Usage
lvmu=$(lsblk | grep -q "lvm" && echo "yes" || echo "no")

# Established TCP Connections
ctcp=$(ss -t state established | wc -l)

# Logged-in Users
ulog=$(who | cut -d " " -f1 | sort -u | wc -l)

# Network Information
ip=$(hostname -I | awk '{print $1}')
mac=$(ip link show | awk '/ether/ {print $2}')

# Sudo Commands Executed
cmds=$(journalctl _COMM=sudo | grep COMMAND | wc -l)

# Display System Information
wall "  
    #Architecture: $architectur
    #CPU physical: $cpuphysical
    #vCPU: $cpuvirtual
    #Memory Usage: $memoryusage
    #Disk Usage: $usagedisk/${fulldisk}Gb ($pordisk%)
    #CPU load: $cpuload
    #Last boot: $lastboot
    #LVM use: $lvmu
    #Connections TCP: $ctcp ESTABLISHED
    #User log: $ulog
    #Network: IP $ip ($mac)
    #Sudo: $cmds commands executed"