initial ubuntu server setup

initial.sh

printf '\e[1;34m%b\e[m' "\nUpdating the system...\n"
apt-get -y -qq update
DEBIAN_FRONTEND=noninteractive apt-get -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" dist-upgrade

NEW_USER=${1:-admin}
SSH_PORT=${2}

if [ ! -d /home/${NEW_USER} ]; then
  printf '\e[1;34m%b\e[m' "\nCreating user '$NEW_USER'...\n"
  adduser --gecos "" $NEW_USER
  mkdir /home/$NEW_USER/.ssh
  chmod 700 /home/$NEW_USER/.ssh

  printf '\e[1;34m%b\e[m' "\nAdding ssh keys to $NEW_USER...\n"
  cp /root/.ssh/authorized_keys /home/$NEW_USER/.ssh/
  chmod 400 /home/$NEW_USER/.ssh/authorized_keys
  chown $NEW_USER:$NEW_USER /home/$NEW_USER -R

  printf '\e[1;34m%b\e[m' "\nGranting sudo rights to $NEW_USER\n"
  adduser $NEW_USER sudo

  # make ssh a little more secure
  printf '\e[1;34m%b\e[m' "\nDisabling ssh root login...\n"
  sed -e 's/^PermitRootLogin .*$/PermitRootLogin no/' -i /etc/ssh/sshd_config
  sed -e 's/#\{0,1\}PasswordAuthentication .*$/PasswordAuthentication no/' -i /etc/ssh/sshd_config

  if [ -n "${SSH_PORT}" ]; then
    printf '\e[1;34m%b\e[m' "\nChanging SSH port to ${SSH_PORT}...\n"
    sed -e "s/^Port .*$/Port ${SSH_PORT}/" -i /etc/ssh/sshd_config
  fi

  reload ssh
fi

printf '\e[1;34m%b\e[m' "\nSetting up basic firewall...\n"
apt-get -y -qq install ufw

if [ -n "${SSH_PORT}" ]; then
  ufw delete allow ssh
  ufw allow ${SSH_PORT}/tcp
else
  ufw allow ssh
fi

echo "y" | ufw enable
ufw status

printf '\e[1;34m%b\e[m' "\nDone!\n"

./initial.sh $user $ssh_port

you can now (optionally) set a different port for sshd to listen on.