install_ssh.sh

#!/bin/bash

# Global variables
SSH_CONFIG="/etc/ssh/sshd_config"
SSH_CONFIG_D="/etc/ssh/sshd_config.d/60-cloudimg-settings.conf"

# Function to update system repositories
update_system() {
    sudo apt update && sudo apt upgrade -y
}

# Function to install SSH server
install_ssh_server() {
    sudo apt install openssh-server -y
}

# Function to enable SSH server
enable_ssh_server() {
    sudo systemctl enable ssh
}

# Function to start SSH server
start_ssh_server() {
    sudo systemctl start ssh
}

# Function to enable and start SSH server
enable_and_start_ssh() {
    sudo systemctl enable --now ssh
}

# Function to verify SSH server status
verify_ssh_status() {
    sudo systemctl status ssh
}

# Function to enable UFW firewall
enable_ufw_firewall() {
    sudo ufw enable
}

# Function to allow SSH traffic through firewall
allow_ssh_through_firewall() {
    sudo ufw allow ssh
}

# Function to check UFW status
check_ufw_status() {
    sudo ufw status
}

# Function to configure SSH for root login and password authentication
configure_ssh() {
    sudo sed -i -e 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/g' \
                -e 's/^PasswordAuthentication.*/PasswordAuthentication yes/' $SSH_CONFIG
    sudo rm -f $SSH_CONFIG_D
    sudo systemctl restart sshd
}

# Main function
main() {
    update_system
    install_ssh_server
    enable_and_start_ssh
#    verify_ssh_status
    enable_ufw_firewall
    allow_ssh_through_firewall
    check_ufw_status
    configure_ssh
}

# Execute main function
main