Ubuntu Clone Hostname Reset

#!/bin/bash

# Exit on error
set -e

# Check if script is run as root
if [ "$EUID" -ne 0 ]; then
  echo "Please run as root"
  exit 1
fi

# Check if FQDN is provided
if [ -z "$1" ]; then
  echo "Please provide an FQDN"
  exit 1
fi

# Extract hostname and domain from FQDN
FQDN="$1"
NEW_HOSTNAME=$(echo "$FQDN" | cut -d'.' -f1)
DOMAIN=$(echo "$FQDN" | cut -d'.' -f2-)

# Set new hostname
hostnamectl set-hostname "$NEW_HOSTNAME"
echo "$NEW_HOSTNAME" > /etc/hostname

# Update hosts file
sed -i '/^127.0.1.1/d' /etc/hosts
echo "127.0.1.1 $FQDN $NEW_HOSTNAME" >> /etc/hosts

# Reset machine-id
truncate -s 0 /etc/machine-id
rm -f /var/lib/dbus/machine-id
systemd-machine-id-setup

# Clear SSH keys
rm -f /etc/ssh/ssh_host_*
if dpkg -l | grep -q openssh-server; then
  dpkg-reconfigure openssh-server
  systemctl restart ssh
else
  echo "Warning: openssh-server not installed, skipping SSH key regeneration"
fi

# Reset network configuration
# Detect primary network interface
IFACE=$(ip link | awk -F: '$0 !~ "lo|vir|docker|br-|^[^0-9]"{print $2;getline}' | head -n 1 | xargs)
if [ -z "$IFACE" ]; then
  echo "Error: No network interface found"
  exit 1
fi
# Delete existing connections
nmcli -t -f UUID con show | while read -r uuid; do
  nmcli con delete "$uuid" 2>/dev/null || true
done
# Add new ethernet connection
nmcli con add type ethernet ifname "$IFACE" con-name "eth0" autoconnect yes

# Clear logs
find /var/log -type f -name "*.log" -exec truncate -s 0 {} \;

# Remove temporary files
rm -rf /tmp/* /var/tmp/*

echo "VM template reset complete. New FQDN: $FQDN"