Managing a Linux server manually can be time-consuming and error-prone. Automation with Bash scripts simplifies common tasks, ensuring consistency and efficiency. In this guide, we’ll walk through setting up a Linux server and automating routine operations.

Step 1: Setting Up Your Linux Server

Option 1: Local Virtual Machine

• Install VirtualBox or VMware.
• Download Ubuntu Server (recommended) or CentOS/RHEL.
• Allocate:
  • 2 CPU cores
  • 2GB RAM
  • 20GB Storage
• Install the OS and configure SSH for remote access.

Option 2: Cloud Server

• Choose a cloud provider: AWS, Azure, GCP, Linode, or DigitalOcean.
• Create a virtual machine (EC2 instance for AWS).
• Use Ubuntu 22.04 LTS or Amazon Linux 2.
• Set up SSH access with a private key.

Step 2: Basic Server Configuration

1️⃣ Update & Upgrade Packages

sudo apt update && sudo apt upgrade -y  # Ubuntu/Debian
sudo yum update -y  # CentOS/Red Hat

2️⃣ Create a New User & Grant Sudo Privileges

sudo adduser devuser  # Replace 'devuser' with your username
sudo usermod -aG sudo devuser  # Grant sudo access

3️⃣ Set Up SSH Key Authentication

On your local machine:

ssh-keygen -t rsa -b 4096  # Generate SSH key
ssh-copy-id devuser@your-server-ip  # Copy key to the server

Disable password authentication for better security:

sudo nano /etc/ssh/sshd_config
# Change "PasswordAuthentication yes" to "no"
sudo systemctl restart ssh

4️⃣ Set Up a Firewall (UFW)

sudo ufw allow OpenSSH
sudo ufw enable
sudo ufw status

Step 3: Automating Tasks Using Bash

1️⃣ Automate System Updates

Create a script:

nano update.sh

Add the following:

#!/bin/bash
sudo apt update && sudo apt upgrade -y
sudo apt autoremove -y
echo "System updated on $(date)" >> /var/log/update_log.txt

Make it executable:

chmod +x update.sh

Schedule it with cron:

crontab -e

Add this line to run it daily at midnight:

0 0 * * * /home/devuser/update.sh

2️⃣ Automate User Backup

Create a script:

nano backup_users.sh

Add:

#!/bin/bash
tar -czvf /backup/users_$(date +%F).tar.gz /home/
echo "Backup completed at $(date)" >> /var/log/backup_log.txt

Schedule it with cron to run every Sunday at 2 AM:

0 2 * * 0 /home/devuser/backup_users.sh

3️⃣ Automate Service Monitoring

Check if a service (e.g., Nginx) is running and restart if not:

nano check_nginx.sh

#!/bin/bash
if ! systemctl is-active --quiet nginx; then
    sudo systemctl restart nginx
    echo "Nginx restarted on $(date)" >> /var/log/nginx_restart.log
fi

Schedule it to check every 5 minutes:

*/5 * * * * /home/devuser/check_nginx.sh

Step 4: Testing & Verifying Automation

• Run scripts manually:

  ./update.sh
  ./backup_users.sh
  ./check_nginx.sh

• Check logs:

  cat /var/log/update_log.txt
  cat /var/log/backup_log.txt
  cat /var/log/nginx_restart.log