systemd-first-boot-script/scripts/04-create-default-user

#!/bin/bash
# Licence : GPL v3
# Author: Laurent HUBERT
#
# Creates a new user for administrative purposes (in sudo group)
#
cat <<EOF
##################################
# Creating default user          #
##################################
EOF
read -p "Please enter default user name: " the_user

if [ -n "$the_user" ]
then
  echo Creating user $the_user
  # Creates the user but disable the login to set the password later:
  adduser --gecos ,,,, --disabled-login $the_user
  status=$?
else
  # Exit with non zero status
  exit 1
fi

if [ 0 -ne "$status" ]
then
  echo "Error creating $the_user"
  echo "Please try again by rebooting"
else
  adduser $the_user sudo
fi

status=1
while [ 0 -ne "$status" ]
do
  passwd $the_user
  status=$?
  if [ 0 -ne "$status" ]
  then
    echo "Error changing $the_user password"
    echo "Please try again"
  else
    cat <<EOF
************************************
* $the_user : created successfully *
************************************
EOF
    exit 0
  fi
done

echo "An error occurred changing $the_user password"
exit $status