dns-ubuntu.sh

#!/bin/bash
iface=$(ip addr show | awk '/inet.*brd/{print $NF; exit}')
gateway=$(route -n | grep 'UG[ \t]' | awk '{print $2}')
address=$(ip addr show | awk '/inet.*brd/{print $2; exit}')
if which netplan &> /dev/null; then
    yaml=$(ls /etc/netplan/*.yaml | head -n 1)
    sudo cp $yaml $yaml.bak
    sudo tee $yaml << EOF
network:
  version: 2
  ethernets:
    $iface:
      addresses:
      - $address
      gateway4: $gateway
      nameservers:
        addresses:
        - 119.29.29.29
        - 223.5.5.5
EOF
    sudo netplan apply
    sudo systemd-resolve --flush-caches
fi