#!/bin/bash

if [ "$EUID" -ne 0 ]
  then
  echo "Please run as root"
  exit
fi

# set static ip address
if [[ ! -d /etc/cloud ]]
    then
        if [[ ! -f /etc/network/interfaces.bak ]]
            then
                read -r -p "Enter Static IP Address with subnet mask: " staticip
                read -r -p "Enter Gateway IP Address: " gatewayip
                read -r -p "Enter Primary DNS IP Address: " dnsip1
                read -r -p "Enter Secondary DNS IP Address: " dnsip2
                name=$(basename /sys/class/net/e*)
                cp /etc/network/interfaces /etc/network/interfaces.bak
                rm /etc/network/interfaces
                cp /etc/network/interfaces.bak /etc/network/interfaces
                sed -i "s,^iface $name inet dhcp*,iface $name inet static," /etc/network/interfaces
                echo "        address $staticip" >> /etc/network/interfaces
                echo "        gateway $gatewayip" >> /etc/network/interfaces
                cp /etc/resolv.conf /etc/resolv.conf.bak
                rm /etc/resolv.conf
                echo "nameserver $dnsip1" >> /etc/resolv.conf
                echo "nameserver $dnsip2" >> /etc/resolv.conf
                ifdown $name
                ifup $name
                echo "Static IP set successfully."
            else 
                echo "Static IP already set."
        fi
    else 
        echo "Static IP not set on cloud image."
fi