#!/bin/bash
# Prepare Ubuntu Server 18.04 for Cisco Trex

ttyS0_service='/lib/systemd/system/ttyS0.service'


# Check if I am root
 [ "$(id -u)" != 0 ] && echo "Run the script as root, exiting" && exit 1 

# Update packages
 apt-get update
 [ "$?" != 0 ] && echo "System can't be updated, exiting" && exit 1

# Check if we utilities are installed
 for package in ifupdown unzip build-essential libelf-dev zlib1g-dev python3-distutils; do
  dpkg --list | grep "$package" &>/dev/null
  [ "$?" == 1 ] && sudo apt-get -y install "$package"
 done

# Stop renaming interface e.g. eth0 to ens3
 sed -i 's/GRUB_CMDLINE_LINUX=""/GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"/g' /etc/default/grub
 grub-mkconfig -o /boot/grub/grub.cfg

# Redirect video output to serial console
 echo '[Unit]' > "$ttyS0_service"
 echo -e "Description=Serial Console Service\n" >> "$ttyS0_service"
 echo '[Service]' >> "$ttyS0_service"
 echo 'ExecStart=/sbin/getty -L 115200 ttyS0 vt102' >> "$ttyS0_service"
 echo -e "Restart=always\n" >> "$ttyS0_service"
 echo '[Install]' >> "$ttyS0_service"
 echo 'WantedBy=multi-user.target' >> "$ttyS0_service"

 systemctl daemon-reload
 systemctl enable ttyS0
 systemctl start ttyS0
 
 
# Reduce timeout for network interfaces to 15sec during boot
 mkdir -p /etc/systemd/system/networking.service.d
 echo "[Service]" > /etc/systemd/system/networking.service.d/reduce-timeout.conf
 echo "TimeoutStartSec=15" >> /etc/systemd/system/networking.service.d/reduce-timeout.conf

exit 0