network etc host swapper

#!/usr/bin/bash

# ------------------------------------------
#
# place in /etc/NetworkManager/dispatcher.d/
#
# ------------------------------------------


CURRENT_INTERFACE=$1
EVENT=$2

# uuid of 'tofu' (nmcli c)
HOME_UUID="xyz"

# Replace with the interface name (e.g., wlp0s20f3)
HOME_INTERFACE="wlp0s20f3"

# Path to your default hosts file
BASE_HOSTS="/etc/hosts.base"

# Path to the hosts file for your home network
HOME_HOSTS="/etc/hosts.home"

if [[ $CURRENT_INTERFACE != "$HOME_INTERFACE" ]] || [[ $EVENT != "up" && $EVENT != "down" ]]
; then
  exit 0
fi

# this environmental variable is set on UP/DOWN events
if [[ $CONNECTION_UUID != "$HOME_UUID" ]]; then
  exit 0
fi

# Function to swap hosts files
if [ "$EVENT" = "up" ]; then
  cat "$BASE_HOSTS" "$HOME_HOSTS" | sudo tee /etc/hosts
  echo "combined home hosts file"
else
  sudo cp /etc/hosts.base /etc/hosts
  echo "back to base hosts file"
fi