Create a new user and add the SSH public key for Raspberry Pi.

new-user-ssh.sh

#!/bin/bash
printf "What new username to use? "
read user
printf "Which is the public key? "
read public_key
if [ "$user" != "" -a "$public_key" != "" ]; then
  # create user, password required
  sudo adduser $user
  # add the new user to the gpio group
  sudo usermod -a -G gpio $user
  echo "Type the password one more time"
  # create the .ssh directory and add the public key
  su - $user bash -c "mkdir -m 700 ~/.ssh && echo $public_key > ~/.ssh/authorized_keys"
  sudo service ssh restart
  echo "Done"
else
  echo "I need the correct values"
fi