linux-sysadmin-journey/projects/01-homelab-setup/scripting-automation.md

Shell Scripting and Automation

Overview

This document tracks the implementation of shell scripts and automation tasks for our Ubuntu Server VM.

Shell Scripting Basics

1. First Script: System Health Check ✅

#!/bin/bash
# system-health.sh - Basic system health check script

# Create script
sudo nano /usr/local/bin/system-health.sh

Script contents:

#!/bin/bash

# System Health Check Script
echo "=== System Health Check ==="
echo "Date: $(date)"
echo

# System uptime
echo "=== System Uptime ==="
uptime
echo

# Memory usage
echo "=== Memory Usage ==="
free -h
echo

# Disk usage
echo "=== Disk Usage ==="
df -h /
echo

# CPU load
echo "=== CPU Load ==="
mpstat 1 1
echo

# Active system services
echo "=== System Services ==="
systemctl list-units --type=service --state=running
echo

# Recent system logs
echo "=== Recent System Logs ==="
tail -n 5 /var/log/syslog

Script Setup ✅

# Install required package
sudo apt install sysstat

# Make script executable
sudo chmod +x /usr/local/bin/system-health.sh

# Test script
sudo /usr/local/bin/system-health.sh

Test Results ✅

• Script executed successfully
• All system metrics collected:
  • System uptime (4 users, load average visible)
  • Memory usage (1.9GB total, 370MB used)
  • Disk usage (75% used)
  • CPU load (97.11% idle)
  • Active services (15 services running)
  • Recent system logs

Next Improvements

1. Add Error Handling

#!/bin/bash

# Add error handling
set -e  # Exit on error
exec 2> >(tee -a /var/log/system-health.error.log)  # Log errors

# Function for error handling
check_command() {
    if ! command -v $1 &> /dev/null; then
        echo "Error: $1 is not installed" >&2
        exit 1
    fi
}

# Check required commands
check_command free
check_command df
check_command mpstat
check_command systemctl

2. Add Logging

# Add timestamp and logging
LOG_FILE="/var/log/system-health.log"
exec 1> >(tee -a $LOG_FILE)  # Log stdout

Would you like to:

1. Implement these improvements
2. Schedule regular execution
3. Add more system checks

Automation Plan

1. System Health Monitoring

   • Create basic health check script
   • Add error checking
   • Implement logging
   • Schedule regular execution

2. Maintenance Tasks

   • Create cleanup script
   • Automate log analysis
   • Monitor service status

3. Reporting

   • Generate system reports
   • Email notifications
   • Performance tracking

Implementation Status

• Basic Script Creation
• Error Handling
• Logging Implementation
• Automated Scheduling