Ubuntu System Update Script

A comprehensive bash script for checking and applying Ubuntu system updates with interactive prompts, email notifications, and automatic cleanup.

Features

• Interactive Mode: Prompts for user confirmation before applying updates
• Comprehensive Updates: Applies all available system updates using apt upgrade
• Package Cleanup: Automatically removes unused packages and cleans apt cache
• Email Notifications: Sends detailed update reports via email
• Detailed Logging: Creates timestamped logs in /var/log/ for audit trails
• Color-Coded Output: Easy-to-read terminal output with status indicators
• Error Handling: Robust error checking with appropriate exit codes
• Safety Checks: Validates privileges, OS type, and required commands

Requirements

• Operating System: Ubuntu (any supported version)
• Privileges: Must be run with sudo or as root
• Required Packages: apt, apt-get (pre-installed on Ubuntu)
• Optional for Email: mailutils or sendmail

Installing Email Support (Optional)

To enable email notifications, install mailutils:

sudo apt update
sudo apt install mailutils

During installation, you may be prompted to configure the mail system. For most use cases, select "Internet Site" and use your system's hostname.

Installation

1. Download or create the script:

# Navigate to the correct directory
cd /usr/local/bin

# Download the script file using sudo
sudo wget https://raw.githubusercontent.com/authorTom/ubuntu-update-script/79940d7ef9263f81bd517a6313b01da3508b73db/update-system.sh

2. Make the script executable:

sudo chmod +x update-system.sh

3. Verify installation:

sudo ./update-system.sh --help

Usage

Basic Usage (Interactive Mode)

Run the script with sudo. It will prompt you before each major operation:

sudo ./update-system.sh

The script will:

1. Check prerequisites (permissions, OS, commands)
2. Update package lists
3. Display available updates
4. Prompt to install updates
5. Prompt to clean up unused packages

With Email Notifications

Receive a summary report via email:

sudo ./update-system.sh --email admin@example.com

Automatic Mode (No Prompts)

Run without interactive prompts (useful for cron jobs):

sudo ./update-system.sh --yes --email admin@example.com

Command Line Options

Option	Description
-h, --help	Display help message and exit
-e, --email EMAIL	Send notification to specified email address
-y, --yes	Skip confirmation prompts (automatic mode)

Examples

Example 1: Manual Update with Prompts

sudo ./update-system.sh

Output:

================================
Running Prerequisite Checks
================================
[INFO] Checking privileges...
[SUCCESS] Running with appropriate privileges
[INFO] Checking operating system...
[SUCCESS] Ubuntu system detected: Ubuntu 22.04.3 LTS

================================
Updating Package Lists
================================
[INFO] Running apt update...
[SUCCESS] Package lists updated successfully

================================
Checking for Available Updates
================================
[INFO] Found 15 packages with available updates
[INFO] Upgradable packages:
...

Do you want to proceed with installing updates? [y/N]: y

Example 2: Automated Updates with Email

sudo ./update-system.sh --yes --email sysadmin@company.com

This will run unattended and send a report like:

Ubuntu System Update Report
===========================

Server: web-server-01
Date: Wed Nov 11 14:30:22 UTC 2025
User: root

Update Summary:
--------------
Updates Available: 15
Packages Upgraded: 15
Packages Removed: 3
Errors Encountered: 0

Status: SUCCESS

Full log file: /var/log/system-update-20251111-143022.log

Example 3: Scheduled Updates with Cron

Add to root's crontab to run weekly updates on Sunday at 2 AM:

sudo crontab -e

Add this line:

0 2 * * 0 /usr/local/bin/update-system.sh --yes --email admin@example.com

Log Files

Each run creates a timestamped log file:

/var/log/system-update-YYYYMMDD-HHMMSS.log

Example: /var/log/system-update-20251111-143022.log

To view recent logs:

ls -lth /var/log/system-update-*.log | head -5

To view a specific log:

sudo less /var/log/system-update-20251111-143022.log

Exit Codes

The script uses the following exit codes:

Code	Description
0	Success
1	Prerequisite check failed (permissions, OS, commands)
2	Failed to update package lists
3	Failed to apply updates
4	Failed to clean up packages
5	Completed with errors

Troubleshooting

Permission Denied

Problem: [ERROR] This script must be run with sudo or as root

Solution: Always run with sudo:

sudo ./update-system.sh

Email Not Sending

Problem: Email notification fails or is not sent

Solution: Install mailutils and configure:

sudo apt install mailutils
echo "Test email" | mail -s "Test" your@email.com

Package Lock Error

Problem: Could not get lock /var/lib/dpkg/lock-frontend

Solution: Another process is using apt. Wait for it to complete or check:

ps aux | grep -i apt
sudo lsof /var/lib/dpkg/lock-frontend

Script Not Found

Problem: command not found when running the script

Solution: Use the full path or ensure the script is executable:

sudo /usr/local/bin/update-system.sh
# or
sudo chmod +x /path/to/update-system.sh

Security Considerations

• Run as Root: The script requires root privileges to update system packages
• Review Updates: In interactive mode, review the list of updates before confirming
• Log Access: Log files contain system information; ensure proper file permissions
• Email Security: Email notifications may contain sensitive system information
• Cron Jobs: When scheduling, ensure the email system is properly configured

Customization

Change Log Directory

Edit the LOG_FILE variable in the script:

LOG_FILE="/custom/path/system-update-$(date +%Y%m%d-%H%M%S).log"

Modify Email Format

Edit the send_email_notification() function to customize the email body and subject.

Adjust Color Scheme

Modify the color variables at the top of the script:

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
# ... etc

Best Practices

1. Test First: Run in interactive mode first to review changes
2. Check Logs: Review log files after automated runs
3. Email Notifications: Set up email for scheduled/automated updates
4. Regular Schedule: Schedule updates during low-traffic periods
5. Backup First: Consider backing up critical data before major updates
6. Monitor Disk Space: Ensure adequate space for updates (check with df -h)

Advanced Usage

Pre-Update System Backup

Create a wrapper script to backup before updating:

#!/bin/bash
# backup-and-update.sh

echo "Creating system backup..."
# Your backup commands here
rsync -av /important/data /backup/location

echo "Running system updates..."
sudo /usr/local/bin/update-system.sh --yes --email admin@example.com

Notification to Multiple Recipients

Use comma-separated addresses (depends on your mail configuration):

sudo ./update-system.sh --email "admin1@example.com,admin2@example.com"

License

This script is provided for system administration purposes.

Support

For issues, questions, or contributions, please refer to the script documentation or contact your system administrator.

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Last Updated: 2025-11-11 Version: 1.0