A simple script used to update WSL Ubuntu with host file entries you may not want Windows to have access to. place a .hosts file in the same working dir as the script it should be formatted like a hosts file as to not break your host resolution

WSL_HostUpdater.sh

#!/bin/bash
# Ron Egli / github.com/smugzombie
# A simple script used to update WSL Ubuntu with host file entries you may not want Windows to have access to
# place a .hosts file in the same working dir as the script
#  - it should be formatted like a hosts file as to not break your host resolution
# Version 1.0

rootcheck () {
    # A simple check to force sudo if not already root user. If unable quit.
    if [ $(id -u) != "0" ]
    then
        sudo ./"$0" "$@"
        exit $?
    fi
}

# Doublecheck that the user is a sudo user, Otherwise Kill script
rootcheck

while IFS="" read -r hosts || [ -n "$hosts" ]
do
  # Loop through the file, check to see if line already exists in hosts file, If not then we add it.
  found=$(cat /etc/hosts | grep "$hosts")
  if [[ -z "$found" ]]; then
    # Add the line to the hosts file
    echo "$hosts" >> /etc/hosts
    # Let the user know the line has been added
    echo "Added '$hosts' to /etc/hosts"
  fi
done < .hosts